Target body for underwater shooting training

Abstract

The application discloses a target body for underwater shooting training, which comprises a target body, a gas tank, a counterweight, an air bag, a camera and a computing unit. The target body is a sealed liquid storage cavity, which is filled with a water-fast coagulation liquid. The target body is provided with a gas tank interface communicating with the liquid storage cavity, and the gas tank is connected with the interface. The upper and lower parts of the target body are respectively provided with an upper connecting piece and a lower connecting piece. The air bag is connected with the upper connecting piece through a rope, and the counterweight is connected with the lower connecting piece through a rope, so that the target body is vertically suspended in water at a corresponding depth. The camera is arranged towards the target surface and is electrically connected with the computing unit. When the target body is penetrated, the water-fast coagulation liquid overflows from the bullet hole under the action of the gas tank pressure and coagulates rapidly when meeting water, which forms a clear and visible mark at the bullet hole, facilitates the camera to take pictures and identify, and blocks the bullet hole to prevent water from seeping into the target cavity. The application can accurately obtain a bullet impact point underwater, prolong the service life of the target body and reduce the use cost.

Description

Technical Field

[0001] This invention relates to the field of target technology, specifically to an underwater shooting training target. Background Technology

[0002] When frogmen perform special missions underwater, underwater pistols and rifles are essential self-defense weapons. Shooting accuracy often determines a frogman's life or death. Therefore, underwater shooting training is a crucial means to improve their shooting accuracy, and the effectiveness of this training depends on the ability to accurately report underwater targets. Currently, the target reporting methods used in land-based light weapons shooting training mainly fall into three categories: shock wave target reporting, conductive target reporting, and camera target reporting. However, none of these three methods are applicable to underwater targets: underwater pistol and rifle bullets do not reach supersonic speeds in water and do not generate shock waves, thus shock wave target reporting fails; water itself is conductive, especially seawater, and bullet holes on the target surface will be directly short-circuited by the water, preventing the bullet from generating an instantaneous short-circuit signal when penetrating multiple conductive layers, thus conductive target reporting fails; and camera target reporting relies on identifying the shadows formed by light illuminating bullet holes to determine the point of impact. However, underwater, the high density of water and the constant disturbance of light by currents make it almost impossible to form and distinguish the shadows of bullet holes, rendering ordinary camera target reporting unusable.

[0003] The existence of the above problems has resulted in a long-term lack of a target for underwater shooting training that can both accurately identify the bullet impact point and withstand multiple shots, which has seriously affected the training effect. Summary of the Invention

[0004] The purpose of this invention is to provide a target for underwater shooting training, which can actively form a visible mark at the bullet hole after being penetrated, making it easy to capture clearly underwater. At the same time, it can seal the bullet hole to prevent water from seeping into the target cavity, thereby accurately obtaining the bullet impact point in the underwater environment and extending the service life of the target.

[0005] To achieve the above objectives, the present invention proposes the following technical solution: an underwater shooting training target, characterized in that it comprises,

[0006] The target mechanism includes a target body and a water-reacting fast-condensing liquid, wherein the target body is a sealed liquid storage cavity, and the water-reacting fast-condensing liquid is filled in the liquid storage cavity;

[0007] A pressurization mechanism includes a gas tank and a gas tank interface, wherein the gas tank interface is connected to the liquid storage chamber of the target, and the gas tank is connected to the gas tank interface;

[0008] A depth-fixing mechanism includes an airbag and a counterweight. The airbag is connected to the upper part of the target via a rope, and the counterweight is connected to the lower part of the target via a rope.

[0009] An imaging mechanism includes a camera and a computing unit, wherein the camera is positioned facing the target surface of the target and the camera is electrically connected to the computing unit.

[0010] Preferably, the front of the target body is provided with a target surface, and the target body is also provided with a border located on the outer periphery of the target surface;

[0011] The frame is coated with a waterproof fluorescent material.

[0012] The target is an injection-molded plastic cavity. The upper part of the target is provided with an upper circular hole, and the lower part of the target is provided with a lower circular hole. Both the upper circular hole and the lower circular hole are isolated from the liquid storage cavity.

[0013] The airbag is connected to the upper circular hole via a first rope, and the counterweight is connected to the lower circular hole via a second rope;

[0014] Both the first rope and the second rope are adjustable in length, the airbag is a rubber airbag, and the counterweight is a stainless steel block.

[0015] Preferably, the water-based fast-setting liquid includes an aqueous polyurethane grouting liquid, wherein the aqueous polyurethane grouting liquid contains fluorescent microspheres.

[0016] Preferably, the gas tank interface is located at the bottom side of the liquid storage chamber, the gas tank is connected to the gas tank interface via a pipeline, the gas tank is filled with nitrogen, and the pressure of the nitrogen in the gas tank is greater than the water pressure corresponding to the water depth where the target is located;

[0017] A diaphragm-type pressure transmission assembly is provided at the gas tank interface. The diaphragm-type pressure transmission assembly includes an interface housing and a flexible diaphragm disposed within the interface housing. The flexible diaphragm divides the internal space of the interface housing into a gas-side cavity and a liquid-side cavity. The gas-side cavity is connected to the gas tank, and the liquid-side cavity is connected to the liquid storage cavity of the target. The flexible diaphragm can deform towards the liquid-side cavity under the action of gas pressure in the gas-side cavity to transmit the gas pressure to the water-reacting liquid in the liquid storage cavity.

[0018] Preferably, the camera is an underwater camera, and a watertight cable is connected to the camera, which is connected to the computing unit via the watertight cable;

[0019] The camera is fixedly mounted on the bracket and faces the target surface, and the computing unit is a microprocessor.

[0020] The target detection method for underwater shooting training, including the aforementioned underwater shooting training target, includes the following steps:

[0021] S1. Fill the liquid storage chamber of the target with a water-fast solidifying liquid, connect the gas tank to the liquid storage chamber, and make the gas pressure provided by the gas tank greater than the water pressure corresponding to the water depth where the target is located; put the target into the water, and adjust the length of the rope connecting the air bag and the rope connecting the counterweight to make the target vertically suspended at the predetermined water depth.

[0022] S2. Position the camera towards the target surface of the target, and use the camera to capture images of the target surface in real time, and send the captured images to the computing unit;

[0023] S3. After the projectile fired underwater penetrates the target and forms a bullet hole on the target, the flexible diaphragm can deform towards the liquid side cavity under the action of the gas pressure provided by the gas tank, so as to transmit the gas pressure to the water-reacting liquid in the storage cavity and drive the water-reacting liquid to overflow out of the target through the bullet hole.

[0024] S4. Make the water-reacting liquid overflowing from the bullet hole come into contact with the water outside the target and solidify at the bullet hole to form a visible solidification mark at the bullet hole, and seal the bullet hole through the visible solidification mark.

[0025] S5. The computing unit identifies the target's border and the visible solidification mark based on the image captured by the camera, and determines the bullet impact position or firing ring number based on the position of the visible solidification mark on the target surface.

[0026] Preferably, the water-based quick-setting liquid is an aqueous polyurethane grout containing fluorescent microspheres, and the frame of the target is coated with a waterproof fluorescent material.

[0027] In step S4, the aqueous polyurethane grout overflows through the bullet hole and reacts with water to solidify. The fluorescent microspheres are encapsulated and fixed in the solidified material so that the visible solidification mark forms fluorescent spots.

[0028] In step S5, the calculation unit determines the range of the target surface based on the fluorescent profile formed by the waterproof fluorescent material coating, and determines the impact position or the number of firing rings based on the position of the fluorescent spot within the range of the target surface.

[0029] The target detection method for underwater shooting training based on image detection includes the aforementioned underwater shooting training target.

[0030] It also includes pressure regulation using an air pump connected to the air tank, an air valve disposed between the air tank and the liquid storage chamber of the target, and a pressure sensor for detecting the internal pressure of the target;

[0031] The system identifies hit events in continuous target surface images captured by the camera, and after identifying the hit event, acquires post-hit images of the area where the bullet hole is located and the internal pressure of the target detected by the pressure sensor.

[0032] The solidification state of the water-reacting liquid at the bullet hole is determined based on the image after the bullet hits the target. The air pump and air valve are controlled according to the solidification state to adjust the internal pressure of the target body, so that the water-reacting liquid overflows outward at a limited speed before the bullet hole solidifies, and the target body is kept at a preset working pressure after the bullet hole solidifies.

[0033] Preferably, determining the solidification state of the water-reacting liquid at the bullet hole based on the post-hit-target image includes:

[0034] Continuous image tracking is performed on the area where the bullet hole is located to identify the overflow area and solidification mark area formed by the water-reacting liquid. Based on the area change and boundary position change of the solidification mark area and the solidification state recognition result output by the pre-trained image classification model, the degree of solidification of the bullet hole is determined.

[0035] When the solidification degree does not reach the preset solidification threshold, it is determined that the bullet hole has not yet completed solidification;

[0036] When the solidification degree reaches the preset solidification threshold, the air pump is controlled to stop supplying air and the air valve is controlled to enter the pressure holding state. The sealing degree of the bullet hole is determined based on the degree of pressure decay inside the target and the area change of the overflow area during the pressure holding period.

[0037] Preferably, the step of controlling the air pump and air valve to adjust the internal pressure of the target body according to the solidification state includes:

[0038] When the bullet hole has not yet solidified, the air pump is controlled to stop running or the air supply is reduced, and the air valve is controlled to release pressure, so that the first safe pressure difference between the inside of the target and the external water body is maintained. The first safe pressure difference is greater than zero and less than the standby pressure difference before hitting the target, so as to prevent the external water body from entering the target body and limit the speed at which the water-reacting liquid flows out through the bullet hole.

[0039] When the bullet hole has solidified and the sealing degree has reached the preset sealing threshold, the air pump is controlled to replenish the gas tank, and the air valve is controlled to switch between the gas supply state and the pressure holding state, so that the inside of the target body maintains a second working pressure difference. The second working pressure difference is greater than the first safety pressure difference and less than the standby pressure difference, so as to maintain the target surface shape of the target body.

[0040] When the sealing degree fails to reach the preset sealing threshold, the target body is controlled to maintain the first safe pressure difference or further reduce the internal pressure, and an abnormal bullet hole sealing prompt is output.

[0041] Beneficial effects: The technical solution of this application has the following technical effects:

[0042] The target is a sealed reservoir filled with a water-reacting liquid. An air tank maintains a pressure in the reservoir that is higher than the water pressure at the surrounding depth. When the target is pierced by a bullet, the water-reacting liquid overflows from the bullet hole under air pressure and solidifies rapidly upon contact with water, actively forming a brightly colored and fluorescent solidified mark at the bullet hole. This transforms the bullet hole, which was originally indistinguishable underwater due to the lack of shadows, into a clearly visible mark, allowing the camera to capture a clear image of the bullet hole. This solves the problem of the bullet impact point not being accurately obtained underwater in the background technology, effectively improving the target reporting accuracy and training effect of underwater shooting training.

[0043] Meanwhile, the water-fast solidifying liquid can seal the hole after solidifying, preventing water from seeping into the target's liquid storage cavity. This prevents the target from failing due to water immersion after a single shot, thus enabling it to withstand subsequent shots. This solves the problems of water ingress failure, short lifespan, and high cost after the target is penetrated, greatly extending the service life of underwater targets and reducing usage costs.

[0044] In addition, the target is pulled by the upper and lower ropes through the airbag and counterweight, which can make the target stand stably and suspend at the corresponding depth in the water. On the one hand, it can be easily adjusted according to different underwater training scenarios and subjects. On the other hand, it provides a stable target surface for underwater shooting training and clear camera shooting, further ensuring the realization of the above-mentioned target reporting effect.

[0045] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0046] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0047] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0048] Figure 1 This is a schematic diagram of the structure of the present invention;

[0049] Figure 2 This is a schematic diagram of the method flow in Example 3;

[0050] Figure 3 This is a schematic diagram of the structure of Example 3.

[0051] The meanings of the labels in the figures are as follows: 1. Target; 2. Liquid that solidifies rapidly upon contact with water; 3. Gas tank; 4. Counterweight; 5. Airbag; 6. Camera; 7. Computing unit; 8. Air pump; 9. Air valve; 10. Pressure sensor. Detailed Implementation

[0052] The embodiments of the invention are described in detail below with reference to the accompanying drawings to clearly illustrate the structure, purpose, advantages, positional relationships, and connection methods of each component. It should be noted that the directional indications (such as "front," "back," "up," and "down") involved in this embodiment are based on the posture shown in the drawings and are only used to describe the relative positional relationships and movement of the components. If the posture changes, the directional indications will be adjusted accordingly. The term "connection" includes mechanical connections and electrical connections, and can be fixed connections, detachable connections, or indirect connections through an intermediate medium. The specific meaning is understood by those skilled in the art based on the context.

[0053] Example 1

[0054] As shown in Figure 1, this embodiment provides an underwater shooting training target, including a target body 1, a water-soluble liquid 2, an air tank 3, a counterweight 4, an airbag 5, a camera 6, and a computing unit 7. The purpose, function, positional relationship, and connection relationship of each component are described in detail below.

[0055] Target 1 is the main body that withstands bullet fire and displays bullet holes. It is made of high-density polyethylene material and directly blow-molded into a plastic cavity, with a sealed liquid storage chamber inside. Alternatively, it can be formed by sealing two plastic shells made of ABS material, with the mating surfaces sealed by hot-melt welding or sealant to ensure that the liquid storage chamber is not connected to the outside world except for the gas tank interface and bullet holes.

[0056] The target 1 can be made of high-density polyethylene, linear low-density polyethylene, toughened polypropylene, ABS resin, or a composite plastic formed from the above materials, preferably high-density polyethylene or toughened ABS resin. High-density polyethylene is characterized by water resistance, corrosion resistance, impact resistance, and non-brittleness, making it suitable for forming an integral sealed cavity by blow molding or rotational molding. Toughened ABS resin has good dimensional stability, molding accuracy, and surface coating performance, making it suitable for joining the front and rear shells after injection molding. The selected plastic should be chemically compatible with the water-soluble liquid 2 and should not exhibit significant swelling, cracking, or strength reduction due to liquid immersion during normal storage and use.

[0057] The thickness of the wall forming the target surface on the front of the target body 1 can be 1.0–4.0 mm, preferably 1.5–3.0 mm. The thickness of the liquid storage cavity refers to the effective distance between the inner surface of the target surface and the inner surface of the rear wall of the target body 1, which can be 10–40 mm, preferably 15–25 mm. The lower limit of the target surface thickness is used to ensure that the target body 1 has basic structural strength under transportation, placement, and water pressure, avoiding damage or deformation when not fired. The upper limit is used to ensure that underwater projectiles can penetrate the target surface and form relatively concentrated bullet holes, avoiding excessively irregular bullet hole shapes due to excessively thick target surfaces. The selection of the liquid storage cavity thickness takes into account the storage capacity of the water-curing liquid 2, the underwater resistance of the target body 1, and the overall weight, so that there is sufficient liquid supply space on the inner side of the target surface, while avoiding excessively large front and rear dimensions of the target body 1, which would affect the suspension stability and firing use.

[0058] When the target body 1 is integrally molded from high-density polyethylene, a circumferentially continuous and seamless sealed liquid storage cavity can be formed by blow molding, rotational molding, or hollow injection molding. When the target body 1 adopts a front shell and rear shell mating structure, the periphery of the two shells can be sealed by hot plate welding, vibration friction welding, ultrasonic welding, or continuous sealant bonding. A water-resistant sealing ring is set at the gas tank interface and tightened by thread or flange. The allowable working pressure of the target body 1 is measured by the pressure difference between the internal pressure of the liquid storage cavity and the external ambient water pressure of the target body 1. This working pressure difference can be 5-50 kPa, preferably 10-30 kPa. After the target body 1 is manufactured, it can be pressure-held for testing under conditions not less than 1.5 times the maximum allowable working pressure difference, and is considered qualified if there is no significant pressure drop, no leakage, and no irreversible deformation within a predetermined time. The lower limit of the above pressure range can ensure that the water-reacting fast-condensing liquid 2 overcomes the flow resistance and overflows outward through the bullet hole, while the upper limit is used to avoid excessive bulging of the target surface, failure of the sealing connection, or excessive leakage of the water-reacting fast-condensing liquid 2 from the bullet hole.

[0059] The purpose of choosing plastic is twofold: firstly, plastic is relatively soft and tough, allowing bullets to penetrate smoothly and form regular holes without shattering the entire target; secondly, plastic is easy to mold, inexpensive, and easy to coat with a coating on the edges. The front of the target 1 is the target surface, which is the object targeted by the frogman for aiming and shooting, and captured by the camera 6. The target surface can be painted with target rings or human figures using colored waterproof paint. The upper part of the target 1 is equipped with an upper connector, and the lower part is equipped with a lower connector. In this embodiment, both the upper and lower connectors are circular holes opened on the edge of the target 1 shell. These two circular holes are located outside the sealed liquid storage cavity and are isolated from it. Thus, the circular holes are only used to attach ropes without damaging the sealing of the liquid storage cavity, preventing the water-reacting liquid 2 from leaking out of the circular holes.

[0060] Water-reactive fast-setting liquid 2 fills and saturates the sealed reservoir cavity of the target 1, enabling "self-marking of bullet holes" and "sealing and preventing seepage" in this embodiment. In this embodiment, the water-reactive fast-setting liquid 2 can be a liquid material capable of cross-linking, gelling, or solidifying upon contact with water, including single-component hydrophilic polyurethane grouting liquid, two-component aqueous polyurethane grouting liquid, acrylate fast-gelling liquid, and silicate-polymer composite fast-setting liquid. Preferably, a single-component hydrophilic aqueous polyurethane grouting liquid is used, which maintains a flowing state when stored in the sealed reservoir cavity of the target 1 and not in contact with external water. After a bullet hole is formed in the target 1 and overflows from the hole, it can utilize external water to trigger cross-linking and solidification, forming a solid with elasticity and underwater stability at the bullet hole. The above material categories are a further clarification based on the original embodiment's use of aqueous polyurethane grouting liquid with incorporated fluorescent microspheres.

[0061] The initial viscosity of the water-reacting fast-setting liquid 2 at 25°C can be 100–1000 mPa·s, preferably 150–600 mPa·s. If the initial viscosity is below this range, the liquid may spray out too quickly after the bullet hole is formed, making it difficult to control the dosage. If the initial viscosity is too high, it may be difficult to distribute evenly within the reservoir of the target 1, and it may also be difficult to stably overflow through the bullet hole under a limited pressure difference. The solidification time of the water-reacting fast-setting liquid 2 from contact with external water to the formation of a gel or solidified material that no longer flows significantly can be 2–10 seconds; its volume expansion ratio can be 1.2–5.0 times, preferably 1.5–3.0 times. Moderate expansion allows the solidified material to fill the bullet hole and the irregular openings around it, but excessive expansion ratio easily forms excessively large solidified clumps, affecting the identification of the bullet hole location and potentially causing excessive tension on the unstable edges of the bullet hole.

[0062] The solidified material formed after the water-reactive liquid 2 solidifies should be able to adhere to the edge of the bullet hole and the outer surface of the target body 1, and should not easily fall off under water flow disturbance conditions. For the plastic surface of the target body that has been roughened, plasma-treated, or primed, the tensile bond strength of the solidified material should not be less than 0.05 MPa, preferably 0.10 to 0.50 MPa, and should still maintain its sealing and adhesion to the bullet hole after immersion in water for 24 hours. The applicable water temperature range for the water-reactive liquid 2 is 5 to 35°C, preferably 10 to 30°C. The required solidification time can be maintained at different water temperatures by adjusting the catalyst content or reactive group content.

[0063] The fluorescent microspheres can be made of polystyrene, polymethyl methacrylate, or silica-coated fluorescent microspheres, with a particle size of 1–100 μm, preferably 5–50 μm. The amount of fluorescent microspheres added relative to the water-soluble liquid 2 can be 0.05–2.0% by mass, preferably 0.10–1.0% by mass. This particle size and addition range can create fluorescent features that can be recognized by the camera 6, while avoiding significant increases in liquid viscosity, particle sedimentation, or flow obstruction caused by excessively large particles or excessive addition. When excited by underwater light (including natural light or the camera's built-in supplemental light), the polystyrene fluorescent microspheres emit a bright orange fluorescence, making the solidified bullet hole mark appear as a bright orange fluorescent spot with strong contrast to the surrounding water and target surface, which can be clearly distinguished even in underwater environments with flickering light and lack of shadows.

[0064] It is this characteristic of "rapidly solidifying within seconds upon contact with water" that allows the liquid to solidify quickly on the spot once it spills out of the bullet hole and comes into contact with the external water body, without being dispersed by the water flow. This allows it to accumulate at the bullet hole, forming a stable solidification mark and sealing the breach at the same time.

[0065] The purpose of the gas tank 3 is to provide continuous internal pressure to the sealed liquid storage cavity of the target 1, serving as the power source to drive the water-reacting fast-setting liquid 2 to overflow from the bullet hole. The target 1 is equipped with a gas tank interface communicating with the liquid storage cavity. In this embodiment, the gas tank interface is located at the bottom side of the liquid storage cavity. The gas tank 3 is sealed to this gas tank interface via a pipe or thread, thus communicating with the liquid storage cavity. The gas tank 3 is filled with nitrogen gas. Nitrogen gas is chemically stable and does not react with the polyurethane grout, thus avoiding any impact on the water-reacting fast-setting liquid 2. The pressure of the nitrogen gas in the gas tank 3 is set to be greater than the water pressure corresponding to the water depth at which the target 1 is located.

[0066] In this embodiment, a diaphragm-type pressure transmission assembly is provided between the gas tank interface and the liquid storage chamber of the target 1. The diaphragm-type pressure transmission assembly includes an interface housing and a flexible diaphragm. The interface housing is detachably or fixedly installed on the lower side of the target 1 and is located between the gas tank 3 and the liquid storage chamber of the target 1. A flexible diaphragm is disposed inside the interface housing, and the periphery of the flexible diaphragm is sealed to the interface housing, thereby dividing the internal space of the interface housing into a gas-side chamber and a liquid-side chamber. The gas-side chamber is connected to the gas tank 3 through the gas tank interface and pipeline, and the liquid-side chamber is connected to the liquid storage chamber of the target 1 through a liquid inlet.

[0067] The flexible diaphragm can be a circular or elliptical arc-shaped diaphragm, a cup-shaped diaphragm, or a corrugated diaphragm, with an annular sealing edge around its perimeter. The interface housing includes a gas-side housing and a liquid-side housing. The annular sealing edge of the flexible diaphragm is clamped between the mating surfaces of the gas-side housing and the liquid-side housing and is tightened and fixed by threaded connectors, clamps, pressure rings, or flange structures. A water-resistant sealing ring can also be provided on the mating surfaces to prevent gas from entering the liquid-side cavity and to prevent water-reacting liquid 2 from entering the gas-side cavity. The flexible diaphragm can be made of silicone rubber, nitrile rubber, fluororubber, or thermoplastic polyurethane elastomer, preferably silicone rubber or thermoplastic polyurethane elastomer that is water-resistant, resistant to polyurethane grout corrosion, and has good elastic recovery properties. The thickness of the flexible diaphragm can be 0.2–2.0 mm, preferably 0.5–1.2 mm. The effective deformation stroke and corresponding volume compensation of the flexible diaphragm are determined based on the liquid storage chamber capacity, the expected outflow of a single bullet hole, and the predetermined number of consecutive shots, so that the effective volume compensation of the flexible diaphragm is not less than the expected cumulative outflow of the water-crystallizing liquid 2 after the predetermined number of shots.

[0068] When the target 1 is not penetrated, the storage chamber and liquid-side chamber are filled with water-reacting fast-condensing liquid 2. The gas in the gas-side chamber is isolated from the water-reacting fast-condensing liquid 2 by a flexible diaphragm. After the gas supplied by the gas tank 3 enters the gas-side chamber, the gas pressure acts on the side of the flexible diaphragm facing the gas-side chamber, causing the flexible diaphragm to elastically deform towards the liquid-side chamber. The deformation of the flexible diaphragm reduces the effective volume of the liquid-side chamber and applies pressure to the water-reacting fast-condensing liquid 2 in the liquid-side chamber and the storage chamber. Since the liquid-side chamber and the storage chamber are connected, the pressure applied by the flexible diaphragm can be transmitted through the liquid to various areas of the storage chamber.

[0069] When the projectile penetrates the target 1 and forms a bullet hole, the water-reacting fast-condensing liquid 2 in the storage chamber overcomes the ambient water pressure at the bullet hole and overflows to the outside of the target 1 under the pressure. As the water-reacting fast-condensing liquid 2 flows out through the bullet hole, the flexible diaphragm further deforms towards the liquid side cavity to compensate for the volume reduction caused by the liquid outflow and maintains the pressure difference from the storage chamber to the external water body within its effective deformation stroke. The gas in the gas tank 3 does not enter the storage chamber and will not form bubbles in the water-reacting fast-condensing liquid 2; the water-reacting fast-condensing liquid 2 will also not enter the gas tank 3 and its connecting pipelines, thereby improving the stability of pressure transmission and reducing gas path blockage or contamination.

[0070] The effective variable volume of the flexible diaphragm can be determined based on the liquid storage chamber capacity, the predetermined bullet hole size, the expected liquid outflow from a single bullet hole, and the predetermined number of consecutive shots. Preferably, the effective variable volume of the flexible diaphragm is not less than the expected cumulative outflow of the water-soluble liquid 2 after the predetermined number of consecutive shots, so as to ensure that the flexible diaphragm still has sufficient volume compensation stroke during continuous shooting.

[0071] The common purpose of the counterweight 4 and the airbag 5 is to keep the target 1 stably suspended vertically in the water at a corresponding depth, providing a stable target surface for shooting and clear imaging by the camera 6. The counterweight 4 is connected to the lower connector (lower round hole) at the bottom of the target 1 via a rope. In this embodiment, the counterweight 4 is a stainless steel block, which is dense and corrosion-resistant. After sinking to the bottom, it can serve as a positioning anchor point below the target 1, applying a downward pulling force to the target 1. The airbag 5 is connected to the upper connector (upper round hole) at the top of the target 1 via a rope. In this embodiment, the airbag 5 is a rubber airbag that floats on the water surface, applying an upward buoyancy force to the target 1. Thus, the target 1 is pulled upward by the buoyancy of the airbag 5 and pulled downward by the gravity of the counterweight 4. Under the action of tension in two opposite directions, the target 1 is able to be vertically and stably suspended in the water.

[0072] To accommodate different training water depths, the ropes connecting the airbag 5 to the upper connector and the ropes connecting the counterweight 4 to the lower connector are all adjustable in length. By adjusting the length of these two ropes, the height at which the target 1 is suspended in the water can be changed, allowing the target surface to remain at the required shooting depth.

[0073] The purpose of camera 6 is to capture images of the target surface. In this embodiment, camera 6 is an underwater camera, which is set facing the target surface of the target body 1. It can be fixedly installed on an underwater bracket facing the target surface or kept relatively fixed to the target body 1 so that the target surface is always within its field of view, thereby capturing images of the target surface and the orange fluorescent solidification marks at the bullet holes in real time.

[0074] The purpose of the computing unit 7 is to receive and process the images captured by the camera 6. In this embodiment, the computing unit 7 is a microprocessor. The camera 6 is electrically connected to the computing unit 7 via a watertight cable. The image signal captured by the camera 6 is transmitted to the computing unit 7 in real time via this cable. It should be noted that the waterproof fluorescent material coating (such as a hydrophobic polymer composite material) applied to the edge of the target 1 makes the edge of the target surface appear as a bright fluorescent outline in the image, and the solidified orange fluorescent microsphere mark at the bullet hole makes the bullet hole appear as a bright fluorescent spot in the image. Together, these two elements make the outline of the target surface and the position of the bullet hole clearly distinguishable from the background in the captured image. Based on this, the computing unit 7 can obtain the target surface range defined by the outline of the edge and the position of the bullet hole on the target surface. The calculation of the object outline and the position of the point object are common techniques in this field and can be directly implemented by the microprocessor, so they will not be described in detail here.

[0075] The working principle of this embodiment is as follows: Before use, a single-component hydrophilic polyurethane water-swellable grout containing orange polystyrene fluorescent microspheres is filled into the liquid storage chamber of the target 1 and the liquid-side chamber of the interface shell, and residual air in the liquid storage chamber and the liquid-side chamber is discharged. A nitrogen-filled gas tank 3 is sealed to the gas-side chamber of the interface shell through a pipeline, so that the gas-side chamber and the liquid-side chamber are isolated from each other by a flexible diaphragm. Gas tank 3 supplies gas to the gas-side chamber, causing the flexible diaphragm to deform towards the liquid-side chamber, and establishing an equivalent liquid pressure in the liquid storage chamber that is higher than the ambient water pressure corresponding to the water depth of the target 1.

[0076] The target 1 is placed in water, the airbag 5 floats on the surface via an upper rope, and the counterweight 4 sinks to the bottom via a lower rope. By adjusting the lengths of the two ropes, the target 1 is vertically suspended at a predetermined water depth, with its surface facing the camera 6. After the trainee fires at the target 1, the projectile creates a bullet hole in the target 1. Under the gas pressure in the air-side chamber, the flexible diaphragm continues to deform towards the liquid-side chamber, applying pressure to the water-reacting liquid 2 in the storage chamber, causing the water-reacting liquid 2 to overflow through the bullet hole.

[0077] Upon contact with external water, the water-fast solidifying liquid 2 undergoes cross-linking and solidification within 2-10 seconds, encapsulating and fixing the orange fluorescent microspheres within it, thus forming a fluorescent solidification mark at the bullet hole. This fluorescent solidification mark serves two purposes: firstly, it seals the bullet hole, reducing the ingress of external water into the storage chamber; secondly, it works in conjunction with the waterproof fluorescent material coating on the target 1's frame to form a high-contrast image that can be clearly identified by the camera 6. The camera 6 transmits the image to the computing unit 7, which determines the target surface area based on the fluorescent frame and the bullet impact position or the number of firing rings based on the location of the fluorescent solidification mark.

[0078] Example 2

[0079] This embodiment provides a target detection method for underwater shooting training, which is implemented using the underwater shooting training target described in Embodiment 1.

[0080] Before conducting underwater shooting training, the target 1 is first prepared. A single-component hydrophilic polyurethane water-swellable grout containing orange polystyrene fluorescent microspheres is used as water-fast setting liquid 2 to fill the liquid storage cavity of the target 1 and the liquid side cavity of the interface shell. The residual air in the liquid storage cavity and the liquid side cavity is then discharged, so that the water-fast setting liquid 2 is continuously distributed to the inner area of ​​the target surface of the target 1.

[0081] A nitrogen-filled gas cylinder 3 is sealed to the gas-side cavity of the interface housing via a pipeline. A flexible diaphragm is installed between the gas-side cavity and the liquid-side cavity, and the periphery of the flexible diaphragm is sealed to the interface housing, thereby isolating the nitrogen supplied by the gas cylinder 3 from the water-reacting fast-condensing liquid 2. The gas supplied by the gas cylinder 3 only enters the gas-side cavity and indirectly transmits pressure to the water-reacting fast-condensing liquid 2 in the liquid-side cavity and the storage cavity by pushing the flexible diaphragm to deform.

[0082] The gas pressure supplied to the gas-side cavity by the water depth regulating gas tank 3, which is pre-set in the target 1, ensures that the equivalent liquid pressure transmitted from the flexible diaphragm to the liquid storage cavity is greater than the ambient water pressure corresponding to that water depth. The elastic recovery pressure of the flexible diaphragm itself can be obtained through pre-calibration. When determining the equivalent liquid pressure of the liquid storage cavity, it can be corrected based on the gas pressure in the gas-side cavity and the elastic recovery pressure of the flexible diaphragm under the corresponding deformation.

[0083] When the target 1 is penetrated by the projectile, the water-reacting liquid 2 in the storage chamber forms a pressure difference from the inside to the outside under the pressure applied by the flexible diaphragm, and overflows outward through the bullet hole. Because the flexible diaphragm separates the gas from the water-reacting liquid 2, external water and the water-reacting liquid 2 will not enter the gas tank 3 through the liquid side cavity, and the gas in the gas tank 3 will not directly enter the storage chamber to form bubbles.

[0084] Next, target 1 is placed in the training water area. Airbag 5 is connected to the upper circular hole of target 1 via a first rope, causing airbag 5 to float on the water surface and apply an upward traction force to target 1. Counterweight 4 is connected to the lower circular hole of target 1 via a second rope, causing counterweight 4 to sink to the bottom and apply a downward traction force to target 1. By adjusting the lengths of the first and second ropes, target 1 is vertically suspended at a predetermined water depth, with the target face facing the firing direction.

[0085] Camera 6 is mounted on an underwater support and oriented towards the target surface of target 1. The distance and orientation between camera 6 and target 1 are adjusted so that the entire target surface of target 1 is within the field of view of camera 6. Camera 6 is connected to computing unit 7 via a watertight cable and acquires target surface images in real time during shooting training.

[0086] The frame of the target 1 is coated with a waterproof fluorescent material. Under underwater illumination or supplemental lighting from the camera 6, the frame forms a fluorescent outline with a clear contrast to the surrounding water and the target surface. The camera 6 transmits the captured target surface image to the computing unit 7 in real time, and the computing unit 7 determines the position of the target 1 and the target surface range in the image based on the fluorescent outline.

[0087] During shooting training, trainees use underwater pistols or underwater rifles to fire at target 1. When the projectile penetrates target 1, it creates a bullet hole in the target 1 that connects the liquid storage chamber to the external water. Because the gas pressure provided by gas tank 3 is greater than the ambient water pressure at the location of target 1, the water-reacting liquid 2 in the liquid storage chamber of target 1 overflows outward through the bullet hole under the action of the pressure difference.

[0088] Upon overflowing from the bullet hole, the water-based rapid-setting liquid 2 immediately comes into contact with external water. The water-based polyurethane grout then reacts and rapidly cross-links and solidifies near the bullet hole. During the solidification process, the orange polystyrene fluorescent microspheres dispersed in the water-based polyurethane grout are encapsulated and fixed within the polyurethane solidified material, thus forming a stable orange fluorescent solidification mark at the bullet hole.

[0089] The orange fluorescent solidified markers are attached to and around the bullet holes, sealing the openings and reducing the inflow of external water into the target's liquid reservoir. They also transform ordinary bullet holes, which are normally difficult to identify underwater due to a lack of stable shadows, into brightly colored, fluorescent dots. Even with water currents or light fluctuations in the training area, the fluorescent solidified markers still create a clear image contrast with the target surface.

[0090] Camera 6 continues to acquire images of the target surface and transmits the images, including the fluorescent border and fluorescent solidification marks, to computing unit 7. Computing unit 7 first determines the target surface range based on the fluorescent outline of the target 1's border, then identifies fluorescent spots formed by the fluorescent solidification marks within the target surface range, and determines the impact position or the corresponding firing ring number based on the position of the fluorescent spots on the target surface.

[0091] During continuous firing training, after each bullet creates a new bullet hole on target 1, a fluorescent solidification mark is formed at the corresponding bullet hole by a water-based fast-curing liquid 2, following the process described above. The calculation unit 7 identifies the position of each fluorescent solidification mark on the target surface to obtain the bullet impact position or ring number for each shot, thereby completing real-time target detection for underwater firing training.

[0092] In this embodiment, the pressure provided by the gas tank 3 causes the water-reacting fast-curing liquid 2 to overcome the ambient water pressure and overflow from the bullet hole. The water in the training environment then triggers the solidification of the water-reacting fast-curing liquid 2 at the bullet hole, allowing the same solidified material to simultaneously serve as a visual marker and a seal for the bullet hole. By coordinating the fluorescent outline of the target 1's frame with the fluorescent spots at the bullet hole, the visibility of the target area and impact position in underwater images can be improved, thereby achieving real-time target detection for underwater shooting training.

[0093] Example 3

[0094] like Figure 2 and Figure 3 As shown, this embodiment, based on the target 1, water-crystallizing liquid 2, air tank 3, counterweight 4, airbag 5, camera 6, and computing unit 7 described in Embodiments 1 and 2, further includes an air pump 8, air valve 9, pressure sensor 10, flexible diaphragm, interface housing, air-side cavity, and liquid-side cavity, to form an underwater shooting training control method that combines image detection, bullet hole solidification state judgment, pressure detection, and air pressure closed-loop regulation.

[0095] The outlet of the air pump 8 is connected to the inlet of the air tank 3 to replenish the air tank 3. An air valve 9 is located between the air tank 3 and the air-side cavity of the interface housing. The air valve 9 is preferably a three-way electromagnetic proportional valve with supply, pressure holding, and pressure relief positions. When the air valve 9 is in the supply position, the air tank 3 is connected to the air-side cavity; when it is in the pressure holding position, the air path between the air tank 3, the air-side cavity, and the pressure relief port is cut off; when it is in the pressure relief position, some gas in the air-side cavity is discharged through the pressure relief port to reduce the pressure applied by the flexible diaphragm to the water-reacting quick-condensing liquid 2.

[0096] A flexible diaphragm is positioned between the gas tank interface and the liquid storage chamber of the target 1, and is sealed within the interface housing. The flexible diaphragm divides the interface housing into a gas-side chamber and a liquid-side chamber. The gas-side chamber is connected to the gas valve 9, and the liquid-side chamber is connected to the liquid storage chamber of the target 1. The gas pressure in the gas-side chamber pushes the flexible diaphragm to deform towards the liquid-side chamber, reducing the effective volume of the liquid-side chamber and transmitting pressure to the water-reacting, rapidly solidifying liquid 2 in the liquid storage chamber.

[0097] The pressure sensor 10 is disposed within the gas-side cavity or on a gas pipeline near the gas-side cavity to detect the gas pressure within the gas-side cavity. The calculation unit 7 determines the equivalent liquid pressure within the storage cavity based on the gas-side pressure detected by the pressure sensor 10 and the pre-calibrated elastic recovery pressure of the flexible diaphragm. Alternatively, the pressure sensor 10 may be a liquid pressure sensor with a corrosion-resistant diaphragm, disposed within the liquid-side cavity or on a liquid passage communicating with the liquid-side cavity, to directly detect the liquid pressure within the storage cavity.

[0098] The computing unit 7 is electrically connected to the camera 6, air pump 8, air valve 9, and pressure sensor 10. The computing unit 7 receives target surface images and pressure detection signals, determines whether a hit has occurred, whether the water-reacting liquid 2 has solidified, and the sealing degree of the bullet hole based on the target surface image, and adjusts the gas pressure in the air-side cavity according to the determination results. Pressure changes in the air-side cavity are transmitted to the water-reacting liquid 2 through a flexible diaphragm, thereby limiting the outflow rate of the liquid before the bullet hole solidifies, and maintaining the working pressure in the liquid storage cavity after the bullet hole solidifies to maintain the target surface shape.

[0099] The control method provided in this embodiment includes the following steps.

[0100] S301, Target placement, system initialization and initial pressure establishment.

[0101] Fill the reservoir cavity of target 1 and the liquid-side cavity of interface housing with water-soluble fast-condensing liquid 2 containing fluorescent microspheres, and then expel the residual air in the reservoir cavity and liquid-side cavity. Connect gas tank 3 to the gas-side cavity of interface housing via gas valve 9, and connect air pump 8 to the air inlet of gas tank 3. Connect airbag 5 to the upper part of target 1 via rope, and connect counterweight 4 to the lower part of target 1 via rope. By adjusting the length of the two ropes, target 1 is vertically suspended at a predetermined water depth, with the target surface facing camera 6.

[0102] Calculation unit 7 determines the ambient water pressure outside target 1 based on the set water depth of target 1. The ambient water pressure is determined according to the following formula:

[0103]

[0104] In the formula, For target 1 at time The ambient water pressure at the location This refers to the atmospheric pressure at the water surface. To train the density of water in the aquatic area, It is the acceleration due to gravity. For target 1 at time The depth relative to the water surface; when the depth of target 1 remains constant, It is a fixed value.

[0105] Pressure sensor 10 detects the gas pressure in the gas-side cavity. Calculation unit 7 determines the equivalent liquid pressure in the liquid-side cavity and the storage cavity based on the gas pressure in the gas-side cavity, the pre-calibrated parameters of the flexible diaphragm, and the current deformation state of the flexible diaphragm. The pre-calibrated parameters include at least the elastic recovery pressure of the flexible diaphragm under different deformation amounts, enabling calculation unit 7 to correct the difference between the gas-side pressure and the equivalent liquid-side pressure. Calculation unit 7 determines the internal and external pressure difference of target 1 based on the internal pressure of target 1 and the ambient water pressure.

[0106]

[0107] In the formula, For target 1 at time The internal and external pressure difference, The pressure inside the target 1 detected by pressure sensor 10. The external environmental water pressure of target 1.

[0108] Before firing begins, the calculation unit 7 controls the air pump 8 to fill the air tank 3 with air and controls the air valve 9 to be in the air supply position, so that the gas enters the air-side cavity and pushes the flexible diaphragm toward the liquid-side cavity to produce initial deformation, thereby establishing an initial standby pressure difference in the liquid storage cavity that is greater than the ambient water pressure. The initial standby pressure difference should be sufficient to allow the water-reacting liquid 2 to overcome the ambient water pressure and overflow after the bullet hole is formed, while being less than the maximum allowable working pressure difference of the target body 1, so as to avoid significant bulging of the target surface or the flexible diaphragm exceeding the allowable deformation stroke.

[0109] This step establishes a stable gas source through the combined action of air pump 8, air tank 3, and air valve 9. Air tank 3 serves as a gas storage and pressure buffer, reducing pressure fluctuations caused by the start and stop of air pump 8. Air valve 9 is used for fine-tuning the gas entering the liquid storage chamber of target 1. Pressure sensor 10 provides feedback on the actual pressure, thus preventing inaccuracies in the actual pressure inside target 1 caused by relying solely on the rated pressure of air tank 3.

[0110] S302, Target Incident Detection and Bullet Hole Area Determination.

[0111] During shooting training, camera 6 continuously acquires images of the target surface of target 1 and transmits the images to computing unit 7. Computing unit 7 first identifies the target surface boundary based on the waterproof fluorescent material coating on the edge of target 1, and performs position registration on continuous images to prevent slight swaying of target 1 caused by water flow from being mistaken for a hit. Subsequently, the images are processed for noise reduction, brightness equalization, and color enhancement to highlight the fluorescent microspheres at the bullet holes and the visible area formed by the water-condensing liquid 2.

[0112] The computing unit 7 can process the target image using a lightweight convolutional neural network trained on sample images. The training samples include at least images of no target hits, images of liquid overflow after a target hit, images of liquid solidifying, images of solidified liquid, images of water bubble interference, and images of light swaying. The convolutional neural network outputs newly added bullet hole regions, liquid overflow regions, and solidification marker regions. To improve the reliability of target hit detection, the computing unit 7 also calculates target hit feature values ​​based on the changes in adjacent images:

[0113]

[0114] In the formula, For a moment The mid-target feature value, This is a weighting coefficient between the image change and the area of ​​the newly added region, with a value ranging from zero to one. This represents the total number of pixels within the effective area of ​​the target surface. The effective target area is determined based on the fluorescence border. For the current frame image after location registration, at the pixel point Pixel value at that location, This refers to the pixel value at the same pixel point in the previous frame image after location registration. The area of ​​any new bullet hole or new spillway area identified by the intelligent algorithm. This represents the total area of ​​the effective target region.

[0115] When the target feature value exceeds the preset target-hitting threshold for multiple consecutive sampling periods, and the pressure sensor 10 detects a corresponding transient change in the internal pressure of the target 1, the calculation unit 7 determines that the target 1 has been hit, and identifies the newly changed area as the tracking area for this bullet hole. By using both image changes and pressure changes for dual judgment, false judgments caused by bubbles in the water, aquatic plants, light flickering, or the swinging of the target 1 can be reduced.

[0116] S303, Test for the solidification degree and sealing degree of bullet holes.

[0117] After determining the bullet hole region, calculation unit 7 continuously tracks the region. When the water-reacting fast-setting liquid 2 first flows out of the bullet hole, the overflow area typically expands rapidly, with its boundary shape changing quickly. As the water-reacting fast-setting liquid 2 reacts with water and gradually solidifies, the area and boundary position of the overflow area gradually stabilize, and the fluorescence intensity and outline of the solidified material also tend to stabilize. Based on these patterns, calculation unit 7 determines the degree of bullet hole solidification according to the sealing state probability, solidification area change, and solidification boundary displacement output by the intelligent algorithm.

[0118]

[0119] In the formula, For a moment The degree of solidification of the bullet hole; the closer the value is to one, the more complete the solidification. This indicates that the calculation result will be limited to the range of zero to one; , and These are weighting coefficients, and the sum of the three is one. The probability that the bullet hole has solidified or sealed is output by the convolutional neural network. The area of ​​the solidified marked region at the current moment; Interval time The area of ​​the previously solidified marked region; A tiny positive number set to prevent the denominator from being zero; This represents the average displacement of the solidification mark boundary within the current detection cycle. This is the normalized reference value for the boundary displacement.

[0120] When the solidification degree has not yet reached the preset solidification threshold, the calculation unit 7 determines that the water-reactive liquid 2 at the bullet hole has not completely solidified. At this time, if the internal pressure of the target 1 is too high, the water-reactive liquid 2 will continue to flow out rapidly before solidification is complete. This not only wastes the water-reactive liquid 2, but may also cause the solidified material to be continuously washed away, preventing a stable seal from forming at the bullet hole. Therefore, at this stage, it is necessary to reduce the internal pressure of the target 1 to a safe pressure difference slightly higher than the ambient water pressure, so that the water-reactive liquid 2 can still slowly come into contact with the water body, but without forming an excessively large continuous jet.

[0121] When the solidification degree reaches the preset solidification threshold, the calculation unit 7 controls the air pump 8 to stop operating and controls the air valve 9 to be in the pressure-holding position for a short time, temporarily cutting off the air tank 3, the liquid storage chamber of the target 1, and the pressure relief port. During this pressure-holding detection time, the calculation unit 7 judges the sealing degree of the bullet hole based on the amount of pressure decay inside the target 1 and the continued expansion of the overflow area around the bullet hole.

[0122]

[0123] In the formula, This represents the sealing degree of the bullet hole; the closer the value is to one, the better the sealing effect of the bullet hole. and These are the weighting coefficients for the pressure attenuation term and the spillover expansion term; This is the start time of the pressure holding test; The duration of the pressure holding test; The internal pressure of target 1 at the start of the pressure holding test; The internal pressure of target 1 at the end of the pressure holding test; This is the allowable pressure decay reference value used for normalization; This refers to the area of ​​the liquid diffusion region outside the bullet hole at the start of the pressure holding test; This refers to the area of ​​the liquid diffusion region outside the bullet hole at the end of the pressure holding test; This represents the total area of ​​the effective target region.

[0124] If the pressure drops rapidly or the overflow area continues to expand during the pressure holding process, it indicates that the bullet hole has not been reliably sealed; if the pressure is basically stable and the overflow area no longer expands significantly, it indicates that the solidified material has formed a good seal at the bullet hole. Therefore, this embodiment does not judge the sealing effect solely based on the appearance of the solidified material, but combines the image status and the pressure holding status, which can improve the accuracy of the judgment.

[0125] S304. Adaptive pressure control based on solidification and sealing conditions.

[0126] After detecting a target hit, the calculation unit 7 first controls the air pump 8 to stop or reduce its speed, and controls the air valve 9 to switch from the inflation position to the depressurization position, so that the pressure difference between the inside and outside of the target 1 is reduced from the standby pressure difference before firing to a safe pressure difference. This safe pressure difference is greater than zero to prevent external water from flowing back into the target 1, but is significantly less than the standby pressure difference before firing to limit the rapid flow of the water-reacting liquid 2 from the unsolidified bullet hole.

[0127] As the solidification degree increases, the calculation unit 7 gradually adjusts the target pressure difference from the safety pressure difference to the working pressure difference. After the bullet hole has solidified, the working pressure difference is still lower than the initial standby pressure difference before firing, but it can maintain the basic shape of the target 1, preventing the target surface from collapsing significantly due to excessively low internal pressure, and ensuring that the target 1 can continue to withstand subsequent firing. The target pressure difference is determined according to the following formula:

[0128]

[0129] In the formula, For the target internal and external pressure difference determined by calculation unit 7, This is the safety pressure differential used when the bullet hole has not yet solidified. This is the working pressure differential used to maintain the shape of target 1 after the bullet hole solidifies. The degree of solidification of the bullet hole, To begin gradually increasing the pressure to the first solidification threshold, To determine the second solidification threshold for the basic solidification of the bullet hole, and Greater than ; To determine the sealing degree of the bullet hole, The sealing threshold that allows entry into a stable pressure-holding state, This is the pressure adjustment coefficient corresponding to the degree of sealing. and These are the minimum and maximum pressure differentials that are allowed to be used, respectively.

[0130] When the bullet hole is not yet solidified, the target pressure differential is maintained at a safe level. During the solidification process, the target pressure differential gradually changes with the degree of solidification to avoid sudden pressure increases that could damage the unstable solidified material. When the bullet hole has solidified, the target pressure differential is adjusted slightly based on the degree of sealing. With a high degree of sealing, the normal operating pressure can be maintained; with a low degree of sealing, the pressure is further reduced, and the bullet hole area is continuously monitored. If necessary, a prompt to pause firing or replace target 1 is issued.

[0131] The calculation unit 7 performs closed-loop control based on the target pressure difference and the actual pressure difference fed back by the pressure sensor 10. The control quantity can be determined according to the following formula:

[0132]

[0133] In the formula, The pressure error between the target pressure difference and the actual pressure difference. For the target internal and external pressure difference, The actual internal and external pressure difference is fed back by pressure sensor 10. This is the combined control quantity for air pump 8 and air valve 9. This is the proportional control coefficient. The integral control coefficient, These are the differential control coefficients. This is the time variable in integration operations.

[0134] When the control quantity is positive, the calculation unit 7 controls the air pump 8 to operate and controls the air supply channel of the air valve 9 to open according to the corresponding opening degree, so that the air tank 3 replenishes gas to the air-side cavity. After the pressure in the air-side cavity increases, the flexible diaphragm deforms further toward the liquid-side cavity, increasing the pressure applied to the water-reacting fast-condensing liquid 2. When the control quantity is within the preset control dead zone, the calculation unit 7 controls the air pump 8 to stop and puts the air valve 9 in the pressure-holding position to maintain the current deformation state of the flexible diaphragm. When the control quantity is negative, the calculation unit 7 controls the air pump 8 to stop and controls the pressure relief channel of the air valve 9 to open, so that some of the gas in the air-side cavity is discharged, and the pressure applied by the flexible diaphragm to the water-reacting fast-condensing liquid 2 decreases accordingly. The air supply channel and the pressure relief channel are not opened at the same time to avoid short circuits in the air path and pressure oscillations.

[0135] When the control quantity approaches zero, the calculation unit 7 controls the air pump 8 to stop and puts the air valve 9 in the pressure-holding position; when the control quantity is negative, the calculation unit 7 controls the air pump 8 to stop and controls the pressure relief channel of the air valve 9 to open according to the corresponding opening degree to slowly release the gas inside the target body 1. Through the above control method, the internal pressure of the target body 1 can be made to steadily approach the target pressure, avoiding pressure oscillations caused by frequent start-stop of the air pump 8 and repeated switching of the air valve 9.

[0136] The air pump 8 is mainly used to restore the gas storage pressure of the gas tank 3. The gas tank 3 is used to temporarily store gas and absorb the pressure fluctuations generated during the operation of the air pump 8. The air valve 9 is used to directly regulate the inflation, pressure holding and depressurization states of the target 1. The three work together to balance the pressure regulation speed and pressure stability.

[0137] S305, Confirmation of solidification results, target inspection records, and continuous firing control.

[0138] When the solidification degree of the bullet hole continuously reaches the second solidification threshold and the sealing degree continuously reaches the sealing threshold, the calculation unit 7 determines that the bullet hole has been solidified and sealed. The calculation unit 7 controls the air pump 8 and the air valve 9 to maintain the working pressure difference of the target body 1, and saves the target surface image after the bullet hole solidifies, the bullet hole coordinates, the number of firing rings, the solidification time, the sealing degree, and the pressure change curve.

[0139] The calculation unit 7 establishes a target surface coordinate system based on the fluorescent outline of the target body 1's frame, and calculates the impact position and firing ring number based on the position of the solidification mark center relative to the target surface center. For multiple bullet holes formed by continuous firing, the calculation unit 7 establishes corresponding bullet hole tracking areas for each bullet hole, and independently detects the solidification degree and sealing degree of each bullet hole. At the same time, it adjusts the internal pressure of the target body 1 based on the overall pressure change caused by all bullet holes.

[0140] If a bullet hole fails to reach the solidification threshold within a preset time, or if its sealing degree remains below the sealing threshold, the calculation unit 7 controls the target body 1 to maintain a safe pressure difference to prevent the rapidly solidifying liquid 2 from continuing to leak out in large quantities, and outputs a bullet hole sealing abnormality warning; when the pressure sensor 10 detects that the internal pressure of the target body 1 cannot be maintained, or the air pump 8 continues to run but still cannot make the actual pressure difference reach the target pressure difference, the calculation unit 7 can output a warning to stop shooting and replace the target body 1, so as to avoid the target body 1 from failing due to excessive liquid loss or external water entering.

[0141] The working principle of this embodiment is as follows.

[0142] Before firing, the air pump 8 replenishes gas to the air tank 3, which then supplies gas to the air-side cavity of the interface housing via the air valve 9. The gas pressure in the air-side cavity pushes the flexible diaphragm to deform towards the liquid-side cavity, and transmits pressure through the liquid-side cavity to the water-reacting liquid 2 in the storage cavity, making the equivalent liquid pressure in the storage cavity higher than the ambient water pressure outside the target 1. The gas and the water-reacting liquid 2 are isolated by the flexible diaphragm, preventing the gas from entering the storage cavity and forming bubbles, and preventing the water-reacting liquid 2 from flowing back into the air pump 8, air tank 3, air valve 9, and pressure sensor 10.

[0143] After the projectile penetrates the target 1, the water-soluble liquid 2, under the pressure transmitted by the flexible diaphragm, overflows through the projectile hole and cross-links and solidifies upon contact with the external water. The camera 6 captures continuous images after the target is hit, and the computing unit 7 identifies the target hit event through image changes and tracks the liquid overflow area, solidification mark area, and boundary stability state at the projectile hole.

[0144] Before the bullet hole solidifies, the calculation unit 7 controls the air pump 8 to stop or reduce the air supply, and controls the air valve 9 to release some of the gas in the air-side cavity, so that the pressure applied by the flexible diaphragm to the water-reactive liquid 2 is reduced to the first safe pressure difference. The first safe pressure difference is still greater than zero, which can prevent external water from flowing back through the bullet hole, and at the same time reduce the speed at which the water-reactive liquid 2 flows out of the bullet hole, providing stable conditions for the water-reactive liquid 2 to solidify at the bullet hole.

[0145] Once the area and boundary of the solidification mark gradually stabilize, the calculation unit 7 controls the air valve 9 to enter the pressure-holding position and judges the sealing degree of the bullet hole based on the degree of attenuation of the pressure in the air-side cavity or the equivalent liquid pressure in the storage cavity during the pressure-holding period. When the bullet hole has completed solidification and the sealing degree reaches the preset sealing threshold, the calculation unit 7 controls the air pump 8, air tank 3, and air valve 9 to maintain the second working pressure in the air-side cavity. The flexible diaphragm then continuously applies appropriate pressure to the water-reacting fast-condensing liquid 2 to maintain the target surface shape of the target body 1. This avoids both excessive pressure that could break open the unstable solidified material or cause excessive loss of the water-reacting fast-condensing liquid 2, and also prevents the target body 1 from collapsing significantly due to excessively low pressure, ensuring that the target body 1 can continue to be used for underwater shooting training and camera target inspection.

[0146] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A target for underwater shooting training, characterized in that: include, The target mechanism includes a target body (1) and a water-reacting fast-condensing liquid (2), wherein the target body (1) is a sealed liquid storage cavity, and the water-reacting fast-condensing liquid (2) is filled in the liquid storage cavity; The pressurization mechanism includes a gas tank (3) and a gas tank interface, wherein the gas tank interface is connected to the liquid storage chamber of the target (1), and the gas tank (3) is connected to the gas tank interface; The depth-fixing mechanism includes an airbag (5) and a counterweight (4). The airbag (5) is connected to the upper part of the target (1) via a rope, and the counterweight (4) is connected to the lower part of the target (1) via a rope. The imaging mechanism includes a camera (6) and a computing unit (7), wherein the camera (6) is disposed facing the target surface of the target (1), and the camera (6) is electrically connected to the computing unit (7).

2. The underwater shooting training target according to claim 1, characterized in that: The front of the target (1) is provided with a target surface, and the target (1) is also provided with a frame located on the outer periphery of the target surface; The frame is coated with a waterproof fluorescent material. The target (1) is a plastic cavity formed by injection molding. The upper part of the target (1) is provided with an upper circular hole, and the lower part of the target (1) is provided with a lower circular hole. The upper circular hole and the lower circular hole are isolated from the liquid storage cavity. The airbag (5) is connected to the upper circular hole via the first rope, and the counterweight (4) is connected to the lower circular hole via the second rope; Both the first rope and the second rope are adjustable in length, the airbag (5) is a rubber airbag, and the counterweight (4) is a stainless steel block.

3. The underwater shooting training target according to claim 2, characterized in that: The water-based fast-setting liquid (2) includes an aqueous polyurethane grouting liquid, which contains fluorescent microspheres.

4. The underwater shooting training target according to claim 3, characterized in that: The gas tank interface is located at the bottom side of the liquid storage chamber. The gas tank (3) is connected to the gas tank interface via a pipeline. The gas tank (3) is filled with nitrogen, and the pressure of the nitrogen in the gas tank (3) is greater than the water pressure corresponding to the water depth at which the target (1) is located. A diaphragm-type pressure transmission assembly is provided at the gas tank interface. The diaphragm-type pressure transmission assembly includes an interface housing and a flexible diaphragm disposed in the interface housing. The flexible diaphragm divides the internal space of the interface housing into a gas-side cavity and a liquid-side cavity. The gas-side cavity is connected to the gas tank (3), and the liquid-side cavity is connected to the liquid storage cavity of the target (1). The flexible diaphragm can deform towards the liquid-side cavity under the action of gas pressure in the gas-side cavity to transmit the gas pressure to the water-reacting liquid (2) in the liquid storage cavity.

5. The underwater shooting training target according to claim 4, characterized in that: The camera (6) is an underwater camera, and a watertight cable is connected to the camera (6). The camera (6) is connected to the computing unit (7) via the watertight cable. The camera (6) is fixedly mounted on the bracket and faces the target surface, and the computing unit (7) is a microprocessor.

6. A target detection method for underwater shooting training, characterized in that, Including the underwater shooting training target as described in claim 5, the method further includes the following steps: S1. Fill the liquid storage chamber of the target (1) with a water-fast solidifying liquid (2), connect the gas tank (3) to the liquid storage chamber, and make the gas pressure provided by the gas tank (3) greater than the water pressure corresponding to the water depth of the target (1); put the target (1) into the water, and adjust the length of the rope connecting the air bag (5) and the rope connecting the counterweight (4) to make the target (1) vertically suspended at the predetermined water depth; S2. The camera (6) is positioned facing the target surface of the target (1), and the camera (6) collects images of the target surface in real time and sends the collected images to the computing unit (7). S3. After the projectile fired underwater penetrates the target (1) and forms a bullet hole on the target (1), the flexible diaphragm can deform towards the liquid side cavity under the action of the gas pressure provided by the gas tank (3), so as to transmit the gas pressure to the water-reacting liquid (2) in the liquid storage cavity, and drive the water-reacting liquid (2) to overflow out of the target (1) through the bullet hole. S4. Make the water-reacting liquid (2) overflowing from the bullet hole come into contact with the water outside the target (1) and solidify at the bullet hole to form a visible solidification mark at the bullet hole, and seal the bullet hole through the visible solidification mark. S5. The computing unit (7) identifies the frame of the target (1) and the visible solidification mark based on the image captured by the camera (6), and determines the bullet impact position or the number of firing rings based on the position of the visible solidification mark on the target surface.

7. The target detection method for underwater shooting training according to claim 6, characterized in that: The water-based quick-setting liquid (2) is an aqueous polyurethane grouting liquid doped with fluorescent microspheres, and the frame of the target (1) is provided with a waterproof fluorescent material coating. In step S4, the aqueous polyurethane grout overflows through the bullet hole and reacts with water to solidify. The fluorescent microspheres are encapsulated and fixed in the solidified material so that the visible solidification mark forms fluorescent spots. In step S5, the calculation unit (7) determines the range of the target surface based on the fluorescent profile formed by the waterproof fluorescent material coating, and determines the impact position or the number of firing rings based on the position of the fluorescent spot within the range of the target surface.

8. A target detection method for underwater shooting training based on image detection, characterized in that: Including the underwater shooting training target as described in claim 5, It also includes an air pump (8) connected to the air tank (3), an air valve (9) disposed between the air tank (3) and the liquid storage chamber of the target (1), and a pressure sensor (10) for detecting the internal pressure of the target (1) for pressure regulation; In the continuous target surface images captured by the camera (6), the target hit event is identified, and after the target hit event is identified, the target hit image of the area where the bullet hole is located and the internal pressure of the target body detected by the pressure sensor (10) are obtained. The solidification state of the water-reacting liquid (2) at the bullet hole is determined based on the image after the target is hit, and the air pump (8) and air valve (9) are controlled according to the solidification state to adjust the internal pressure of the target body (1), so that the water-reacting liquid (2) overflows outward at a limited speed before the bullet hole solidifies, and the target body (1) is kept at a preset working pressure after the bullet hole solidifies.

9. The target detection method for underwater shooting training based on image detection according to claim 8, characterized in that: The determination of the solidification state of the water-reacting liquid (2) at the bullet hole based on the image after the target is hit includes: Continuous image tracking is performed on the area where the bullet hole is located to identify the overflow area and solidification mark area formed by the water-reacting liquid (2). Based on the area change, boundary position change and solidification state recognition result output by the pre-trained image classification model of the solidification mark area, the degree of solidification of the bullet hole is determined. When the solidification degree does not reach the preset solidification threshold, it is determined that the bullet hole has not yet completed solidification; When the solidification degree reaches the preset solidification threshold, the air pump (8) is controlled to stop supplying air and the air valve (9) is controlled to enter the pressure holding state. The sealing degree of the bullet hole is determined according to the degree of pressure decay inside the target (1) and the area change of the overflow area during the pressure holding period.

10. The target detection method for underwater shooting training based on image detection according to claim 9, characterized in that: The method of controlling the air pump (8) and air valve (9) to adjust the internal pressure of the target (1) according to the solidification state includes: When the bullet hole has not yet solidified, control the air pump (8) to stop running or reduce the air supply, and control the air valve (9) to release pressure, so that the inside of the target (1) and the external water body maintain a first safe pressure difference. The first safe pressure difference is greater than zero and less than the standby pressure difference before hitting the target, so as to prevent the external water body from entering the target (1) and limit the speed at which the water-reacting liquid (2) flows out through the bullet hole. When the bullet hole has solidified and the sealing degree has reached the preset sealing threshold, the air pump (8) is controlled to replenish the gas tank (3), and the air valve (9) is controlled to switch between the gas supply state and the pressure holding state, so that the target body (1) maintains a second working pressure difference inside. The second working pressure difference is greater than the first safety pressure difference and less than the standby pressure difference, so as to maintain the target surface shape of the target body (1). When the sealing degree does not reach the preset sealing threshold, the target (1) is controlled to maintain the first safety pressure difference or further reduce the internal pressure, and an abnormal bullet hole sealing prompt is output.

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