Experimental device and method for exploring attack effect of underwater near-field explosion on small-size and small-mass target

Abstract

The invention belongs to the technical field of underwater explosion experiments, and particularly relates to an experimental device and method for exploring the attack effect of underwater near-field explosion on a small-size and small-mass target. The experimental device provided by the invention shows excellent advantages in the aspect of improving scientificity and applicability of an underwater near-field explosion experiment, and lays a solid foundation for deeply researching a damage mechanism of a small-size and small-mass target; according to the invention, a modular and flexible design is adopted, accurate and synchronous data acquisition, non-contact parameter extraction and intelligent nonlinear motion analysis can be realized, the system adapts to a complex experiment scene, a reliable experiment platform is provided for research on a damage mechanism of a small target, and a technical foundation is laid for attack and defense tests of an underwater unmanned system.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater explosion experiments, and in particular relates to an experimental device and method for exploring the attack effect of underwater near-field explosion on a small-size and small-mass target. Background Art

[0002] Underwater unmanned systems are a typical small underwater target, which are characterized by small size and light mass; therefore, under the action of the explosion load, bubbles will wrap up the small volume target or cause the small mass target to move. Current research shows that there are significant differences in the damage effects of the shock wave and bubbles generated by the explosion on the target, which depends on factors such as the size, mass and shape of the target. At present, the wall pressure measurement technology generated by underwater near-field explosions on curved surface boundaries is relatively mature. For example, the Chinese invention patent with application number CN202010557766.5 discloses a multi-angle electric spark bubble wall pressure load test device. However, the existing explosion test device is mainly aimed at larger targets, and the research on small targets is still insufficient, resulting in a lack of effective data and theoretical support to understand the impact of explosions on these targets.

[0003] This type of target exhibits unique response characteristics during the explosion process, which further increases the difficulty of research. However, there is currently a lack of experimental devices that can simulate these conditions in the laboratory. Therefore, it is particularly necessary to develop an explosion experimental device that can adapt to small-sized and small-mass targets in order to provide more accurate experimental data for damage assessment and protection design. Summary of the invention

[0004] The purpose of the present invention is to provide an experimental device and method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets.

[0005] An experimental device for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets, comprising a slot plate, an experimental bracket, an experimental water tank, a high-voltage electric control box, an electric spark base, a first experimental cylinder mounting mechanism, and a second experimental cylinder mounting mechanism;

[0006] The slot plate is provided with a positioning hole and two slots, and the positioning hole is located between the two slots; the experimental water tank is installed in the experimental bracket, and a crossbeam is installed on the top of the experimental bracket, and a structural frame extending in the vertical direction is provided on the crossbeam; the electric spark base is installed in the experimental water tank, and a discharge needle column is installed on the electric spark base, and a discharge needle is installed on the upper end of the discharge needle column; light sources and high-speed cameras are provided on both sides of the experimental bracket; the high-speed camera is equipped with a signal acquisition instrument to capture the contact process between the electric spark bubble and the experimental cylinder; the high-voltage electric control box is connected to the discharge needle through a wire, and is connected to the high-speed camera and the signal acquisition instrument through a synchronous sensor to ensure that the high-voltage electric control box, the high-speed camera and the signal acquisition instrument work synchronously;

[0007] The first experimental cylinder installation mechanism comprises a first experimental cylinder and two sets of sliding positioning pieces, the spacing between the two sets of sliding positioning pieces is adapted to the first experimental cylinder, and the upper end of the first experimental cylinder is fixed to the lower ends of the two sets of sliding positioning pieces;

[0008] The second experimental cylinder installation mechanism includes a second experimental cylinder and two groups of slides, and the spacing between the two groups of slides is adapted to the second experimental cylinder; the slide includes an upper annular installation opening and a lower slide rail; the two ends of the second experimental cylinder are respectively arranged in the lower slide rails of the slides on both sides.

[0009] An experimental method for exploring the attack effect of underwater near-field explosion on a small-sized and small-mass target includes the following steps:

[0010] Step 1: Design the first experimental cylinder and the second experimental cylinder according to the small size and small mass target;

[0011] The first experimental cylinder is a complete cylinder, and the second experimental cylinder has slide grooves at both ends, and the radius and mass of the first experimental cylinder are equal to those of the second experimental cylinder;

[0012] Step 2: Arrange the slot plate vertically and install it at the lower end of the structural frame. After adjusting the spacing between the two sets of sliding positioning pieces, fix the upper end of the first experimental cylinder to the lower ends of the two sets of sliding positioning pieces, and fix the upper ends of the two sets of sliding positioning pieces in the notches of the slot plate;

[0013] Step 3: Pour water into the experimental water tank, adjust the longitudinal position of the spark base according to the experimental content, so that the first experimental cylinder and the discharge needle are located below the water surface, and the distance between the first experimental cylinder and the discharge needle meets the experimental requirements; adjust the light source and the high-speed camera so that the light intensity of the light source meets the experimental needs, and make the shooting position of the light source and the high-speed camera on the same horizontal line with the discharge needle;

[0014] Step 4: Start the experiment of the first experimental cylinder, use the high-voltage electric control box to make the underwater discharge needle generate underwater bubbles, and the high-speed camera and signal acquisition instrument work synchronously;

[0015] Step 5: Unload the first experimental cylinder, the sliding positioning piece and the slot plate; arrange the slot plate horizontally and install it at the lower end of the structural frame, insert the upper annular mounting openings of the two sets of sliding pieces into the two slots of the slot plate through the positioning sliders, adjust the spacing between the two sets of sliding pieces by sliding the positioning sliders, and then set the left and right ends of the second experimental cylinder in the lower slide rails of the sliding pieces on both sides, and fix the two sets of positioning sliders in the positioning openings of the slot plate;

[0016] Step 6: Adjust the water level in the experimental water tank, the initial position and distance between the second experimental cylinder and the discharge needle, the light source and the shooting position of the high-speed camera, which are consistent with step 3;

[0017] Step 7: Start the experiment of the second experimental cylinder. Use the high-voltage electric control box to make the underwater discharge needle generate the same underwater bubbles as in step 4. The second experimental cylinder moves in the vertical direction along the lower slide rails of the slides on both sides under the action of the bubble explosion. The high-speed camera and the signal acquisition instrument work synchronously.

[0018] Step 8: According to the video captured by the high-speed camera, process frame by frame, convert each frame into a grayscale image, apply Gaussian blur to smooth the image, and then obtain the contours of the bubble and the first experimental cylinder and the second experimental cylinder through edge detection and binary filling.

[0019] Features are extracted from each connected area of ​​the bubble contour, and the variation law of the bubble pulsation velocity with the distance parameter in the two experiments is obtained based on the image size and proportional size; feature points are extracted from each connected area of ​​the first experimental cylinder and the second experimental cylinder, the displacement of the second experimental cylinder is identified, and the Hurst exponent of the displacement time series is calculated based on the rescaled range analysis method. The nonlinear motion law of the second experimental cylinder is obtained based on the Hurst exponent, and the experiment on the attack effect of underwater near-field explosion on small-sized and small-mass targets is completed.

[0020] Furthermore, in step 2, the trough plate is arranged vertically and fixed to the lower end of the structural frame by bolts at the four corners.

[0021] Furthermore, in step 2, the upper end of the sliding positioning piece is respectively fixed in two notches on the slot plate by positioning bolts.

[0022] Furthermore, in step 2, the upper end of the first experimental cylinder is fixed to the lower end of the sliding positioning plate by means of eyelet screws.

[0023] Furthermore, in step 5, the trough plate is arranged horizontally and fixed to the lower end of the structural frame by corner brackets at the four corners.

[0024] Furthermore, in step 5, mounting holes are provided on both sides of the upper portion of the annular mounting opening of the slide, and are connected to both sides of the lower portion of the positioning slide block by bolts.

[0025] Furthermore, in step 5, the two sets of positioning slide blocks are fixed in the positioning openings of the slot plate by locking bolts.

[0026] Furthermore, in step 8, features are extracted from each connected area of ​​the bubble contour, and after the bubble reaches the maximum radius, the moment when the filling degree is lower than 0.3 is checked as the moment of bubble rupture, and the change curve of the bubble radius and the filling degree is plotted; the expansion speed is defined as a positive value and the contraction speed is defined as a negative value, and the bubble radius variation curve over time, the bubble expansion speed variation curve over time, and the bubble longitudinal position and longitudinal speed variation curve over time are plotted to obtain the variation law of the bubble pulsation speed with the distance parameter in the two experiments.

[0027] Furthermore, the Hurst exponent of the displacement time series calculated based on the rescaled range analysis method in step 8 is specifically:

[0028] Based on the rescaled range analysis method, the mean of the time series is calculated. The time series X = {X1, X2, …, X N}, where N represents the length of the sequence, and X represents the time series of displacement, velocity, and acceleration. First, the mean of the time series is calculated:

[0029]

[0030] Calculate the deviation sequence Y i for:

[0031]

[0032] Calculate the cumulative deviation sequence Z i :

[0033]

[0034] The range of the cumulative deviation series is defined as:

[0035] R(N)=max(Z1,Z2,…,Z N )-min(Z1,Z2,…,Z N )

[0036] That is, calculate the difference between the maximum and minimum values ​​of the Z sequence;

[0037] The standard deviation S(N) of the time series X is:

[0038]

[0039] According to the rescaled range analysis method, the relationship between the rescaled range R / S and the time scale N obeys a power law relationship:

[0040]

[0041] Taking the logarithm, both sides become a linear relationship:

[0042]

[0043] Through linear regression, the slope H value is obtained, which is the Hurst index.

[0044] The beneficial effects of the present invention are:

[0045] The experimental device of the present invention demonstrates outstanding advantages in improving the scientificity and applicability of underwater near-field explosion experiments, and lays a solid foundation for in-depth research on the damage mechanism of small-size and small-mass targets; it adopts modular and flexible design to achieve precise and synchronous data acquisition, non-contact parameter extraction and intelligent nonlinear motion analysis, and adapt to complex experimental scenarios; it provides a reliable experimental platform for the study of the damage mechanism of small targets, and lays a technical foundation for the attack and defense testing of underwater unmanned systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a front view schematic diagram of the first experimental cylinder installation mechanism in the present invention.

[0047] Figure 2 It is a schematic diagram of an isometric view of the first experimental cylinder mounting mechanism of the present invention.

[0048] Figure 3 It is a front view schematic diagram of the second experimental cylinder installation mechanism in the present invention;

[0049] Figure 4 It is a schematic diagram of an isometric view of the second experimental cylinder mounting mechanism of the present invention.

[0050] Figure 5 It is a partial schematic diagram of the electric spark discharge needle in the present invention.

[0051] Figure 6 It is a partial structural schematic diagram of the assembly of the second experimental cylinder installation mechanism and the experimental water tank in the present invention.

[0052] Figure 7 Schematic diagram of the overall structure of the experimental device of the present invention.

[0053] Figure 8 It is a schematic diagram of the assembly of the sliding plate and the positioning slider in the present invention.

[0054] Fig. 9 It is a schematic diagram of the explosion structure of the second experimental cylinder installation mechanism in the present invention.

[0055] Fig.10 It is a schematic diagram of the structure of the second experimental cylinder in the present invention.

[0056] Fig.11 for Fig.10 Schematic diagram of the cross section at AA in the middle. DETAILED DESCRIPTION

[0057] The present invention is further described below in conjunction with the accompanying drawings.

[0058] like Figures 1 to 11 As shown, the present invention provides an experimental device for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets, including a second experimental cylinder 1, a slide rail 2, a groove plate 3, a positioning slide block 4, an angle code 5, a structural frame 6, a sliding positioning plate 7, an eye screw 8, a first experimental cylinder 9, a light source 10, an experimental bracket 11, an experimental water tank 12, a high-speed camera 13, a signal acquisition instrument 14, a high-voltage electric control box 15, a crossbeam 16, an electric spark base 17, a discharge needle column 18, a discharge needle 19, a positioning bolt 20, and a locking bolt 21.

[0059] A positioning hole 32 and two slots 31 are provided on the slot plate 3, and the positioning hole 32 is located between the two slots 31; the experimental water tank 12 is installed in the experimental bracket 11, and a crossbeam 16 is installed on the top of the experimental bracket 11, and a structural frame 6 extending in the vertical direction is provided on the crossbeam 16; the electric spark base 17 is installed in the experimental water tank 12, and a discharge needle column 18 is installed on the electric spark base 17, and a discharge needle 19 is installed on the upper end of the discharge needle column 18; a light source 10 and a high-speed camera 13 are provided on both sides of the experimental bracket 11; the high-speed camera 13 is equipped with a signal acquisition instrument 14 to capture the contact process between the electric spark bubble and the experimental cylinder; the high-voltage electric control box 15 is connected to the discharge needle 19 through a wire, and is connected to the high-speed camera 13 and the signal acquisition instrument 14 through a synchronous sensor to ensure that the high-voltage electric control box 15, the high-speed camera 13 and the signal acquisition instrument 14 work synchronously;

[0060] The first experimental cylinder installation mechanism comprises a first experimental cylinder 9 and two sets of sliding positioning pieces 7, the spacing between the two sets of sliding positioning pieces 7 is adapted to the first experimental cylinder 9, and the upper end of the first experimental cylinder 9 is fixed to the lower ends of the two sets of sliding positioning pieces 7;

[0061] The second experimental cylinder installation mechanism includes a second experimental cylinder 1 and two sets of slides, the spacing between the two sets of slides is adapted to the second experimental cylinder 1; the slide includes an upper annular installation opening 71 and a lower slide rail 2; the two ends of the second experimental cylinder 1 are respectively arranged in the lower slide rails 2 of the slides on both sides.

[0062] An experimental method for exploring the attack effect of underwater near-field explosion on a small-sized and small-mass target includes the following steps:

[0063] Step 1: Design the first experimental cylinder 9 and the second experimental cylinder 1 according to the small size and small mass target;

[0064] The first experimental cylinder 9 is a complete cylinder, and the second experimental cylinder 1 has slide grooves at both ends, and the radius and mass of the first experimental cylinder 9 and the second experimental cylinder 1 are equal;

[0065] Step 2: Arrange the slot plate 3 vertically and fix it to the lower end of the structural frame 6 by bolts at the four corners. After the two sets of sliding positioning pieces 7 are adjusted to a good spacing, the upper ends of the sliding positioning pieces 7 are respectively fixed to the two notches 31 on the slot plate 3 by positioning bolts 20. The upper end of the first experimental cylinder 9 is fixed to the lower end of the sliding positioning piece 7 by eye screws 8.

[0066] Step 3: Pour water into the experimental water tank 12, adjust the longitudinal position of the electric spark base 17 according to the experimental content, so that the first experimental cylinder 9 and the discharge needle 19 are located below the water surface, and the distance between the first experimental cylinder 9 and the discharge needle 19 meets the experimental requirements; adjust the light source 10 and the high-speed camera 13, so that the illumination intensity of the light source 10 meets the experimental requirements, and make the shooting positions of the light source 10 and the high-speed camera 13 and the discharge needle 19 on the same horizontal line;

[0067] Step 4: Start the experiment of the first experimental cylinder 9, make the underwater discharge needle 19 generate underwater bubbles through the high-voltage electric control box 15, and the high-speed camera 13 and the signal acquisition instrument 14 work synchronously;

[0068] Step 5: Unload the first experimental cylinder 9, the sliding positioning piece 7 and the slot plate 3; arrange the slot plate 3 horizontally and fix it to the lower end of the structural frame 6 through the corner codes 5 at the four corners. The upper annular mounting openings 71 of the two sets of slides are inserted into the two notches 31 of the slot plate 3 through the positioning slider 4. Mounting holes are provided on both sides of the upper part of the annular mounting openings 71 of the slides, and are connected to the lower sides of the positioning slider 4 through bolts; after adjusting the spacing between the two sets of slides by sliding the positioning slider 4, the left and right ends of the second experimental cylinder 1 are arranged in the lower slide rails 2 of the slides on both sides, and the two sets of positioning sliders 4 are fixed in the positioning openings 32 of the slot plate 3 through locking bolts 21;

[0069] Step 6: Adjust the water level in the experimental water tank 12, the initial position and distance between the second experimental cylinder 1 and the discharge needle 19, and the shooting position of the light source 10 and the high-speed camera 13, which are consistent with step 3;

[0070] Step 7: Start the experiment of the second experimental cylinder 1, and make the underwater discharge needle 19 generate the same underwater bubbles as in step 4 through the high-voltage electric control box 15. The second experimental cylinder 1 moves in the vertical direction along the lower slide rails 2 of the slides 4 on both sides under the action of the bubble explosion, and the high-speed camera 13 and the signal acquisition instrument 14 work synchronously;

[0071] Step 8: According to the video captured by the high-speed camera 13, each frame is processed frame by frame, each frame is converted into a grayscale image, Gaussian blur is applied to smooth the image, and then the contours of the bubble and the first experimental cylinder 9 and the second experimental cylinder 1 are obtained by edge detection and binary filling;

[0072] Features are extracted from each connected area of ​​the bubble contour, and the variation law of the bubble pulsation velocity with the distance parameter in the two experiments is obtained based on the image size and proportional size; feature points are extracted from each connected area of ​​the first experimental cylinder 9 and the second experimental cylinder 1, the displacement of the second experimental cylinder 1 is identified, and the Hurst exponent of the displacement time series is calculated based on the rescaled range analysis method. The nonlinear motion law of the second experimental cylinder 1 is obtained based on the Hurst exponent, and the experiment on the attack effect of underwater near-field explosion on small-sized and small-mass targets is completed.

[0073] Based on the rescaled range analysis method, the mean of the time series is calculated. The time series X = {X1, X2, …, X N}, where N represents the length of the sequence, and X represents the time series of displacement, velocity, and acceleration. First, the mean of the time series is calculated:

[0074]

[0075] Calculate the deviation sequence Y i for:

[0076]

[0077] Calculate the cumulative deviation sequence Z i :

[0078]

[0079] The range of the cumulative deviation series is defined as:

[0080] R(N)=max(Z1,Z2,…,Z N )-min(Z1,Z2,…,Z N )

[0081] That is, calculate the difference between the maximum and minimum values ​​of the Z sequence;

[0082] The standard deviation S(N) of the time series X is:

[0083]

[0084] According to the rescaled range analysis method, the relationship between the rescaled range R / S and the time scale N obeys a power law relationship:

[0085]

[0086] Taking the logarithm, both sides become a linear relationship:

[0087]

[0088] Through linear regression, the slope H value is obtained, which is the Hurst index.

[0089] The existing experimental cylinder fixing mechanism can only limit the experimental cylinder of a specific size, and the constraint method of the experimental cylinder is single, which cannot meet the needs of exploring the attack effect of explosion on small-sized and small-mass targets.

[0090] When the underwater unmanned system is attacked by the anti-underwater unmanned system directly below, it will move, among which the movement perpendicular to the horizontal plane, that is, the Z direction movement is the most obvious. If the attack intensity is large, it may even damage the underwater unmanned system. The attack process is simulated in the experimental water tank 12, and the underwater unmanned system can be simplified into a cylinder.

[0091] There are two structures of the experimental cylinder, corresponding to two experimental constraints.

[0092] The first constraint condition is that when the experiment is carried out with the first experimental cylinder 9 as the target, the first experimental cylinder 9 has no degree of freedom and the first experimental cylinder fixing mechanism is used. Figure 1 The middle structural frame 6 is installed on the crossbeam 16 by bolts, and the slot plate 3 is fixed to the lowermost side of the structural frame 6 by bolts, that is, the slot plate 3 is perpendicular to the ground; the upper part of the two sliding positioning plates 7 has two through holes, and the positioning bolts 20 pass through the through holes on the sliding positioning plates 7 and the corresponding notches 31 on the slot plate 3, and are connected with the positioning nuts. The positioning bolts 20 fix the sliding positioning plates 7 and the slot plate 3. The sheep eye screw 8 is fixed to the lower end of the sliding positioning plate 7 by bolts, and the self-tapping thread part of the sheep eye screw 8 cooperates with the blind hole thread reserved on the surface of the first experimental cylinder 9. The position of the positioning bolts that cooperate with the sliding positioning plate 7 and the slot plate 3 is changed, and the distance between the two sliding positioning plates 7 is adjusted to adapt to the first experimental cylinders 9 of different lengths.

[0093] The second constraint condition is that when the experiment is carried out with the second experimental cylinder 1 with positioning grooves at both ends as the target, the second experimental cylinder 1 with positioning grooves at both ends is fixed in the X and Y directions, and the Z direction is free for the experiment, that is, the second experimental cylinder with positioning grooves at both ends can only move perpendicular to the ground. Using the second experimental cylinder fixing mechanism, the structural frame 6 is installed on the mounting beam 16 by bolts, the slot plate 3 is connected to the structural frame 6 by bolts and angle codes 5, the slot plate 3 is directly below the structural frame 6, the slot plate 3 is parallel to the ground, and the two positioning sliders 4 are installed in the corresponding slots of the slot plate. There is a through hole at the central symmetry axis of the upper end face of the positioning slider 4, and the locking bolt 21 passes through the through hole and is connected to the positioning port 32 on the center line of the slot plate 3 and the locking nut. By loosening the locking bolt 21 on the upper end face of the positioning slider, the distance between the positioning sliders 4 can be adjusted to adapt to second experimental cylinders of different lengths. In the Z-direction free experiment, the second experimental cylinder 1 with positioning grooves at both ends is clearance-matched with the slide rail 2, and is circumferentially and axially limited with the slide rail 2, ensuring that the second experimental cylinder 1 with positioning grooves at both ends only moves in the Z direction after being subjected to the bubble pulsation load.

[0094] When the underwater near-field electric spark explosion load acts on the surface of the experimental cylinder, the experimental cylinder will have a corresponding response, including movement and damage. By adjusting the installation position of the electric spark base 17, the discharge needle 19 and the experimental cylinder can maintain a certain relative position relationship. The discharge needle 19 is installed on the discharge needle needle column 18, the discharge needle needle column 18 is installed on the electric spark base 17, and the electric spark base 17 is installed on the crossbeam 16. The discharge needle 19, the discharge needle needle column 18, and the electric spark base 17 are all immersed below the water surface in the experimental water tank 12; the position of the experimental cylinder in the experimental water tank 12 can be adjusted by the position of the structural frame 6 on the installation crossbeam 16.

[0095] The high-voltage electric control box 15 is connected to the discharge needle 19 through a wire, and at the same time, the high-voltage electric control box 15 is connected to the high-speed camera 13 and the signal acquisition device 14 through a synchronous sensor. The purpose is to ensure that the high-voltage electric control box 15, the high-speed camera 13, and the data acquisition device work synchronously. Because the time from the generation to the collapse of the underwater explosion bubble is very short (millisecond level), it is necessary for each device to work at the same time to avoid missing relevant data and phenomena due to the short time of the experimental phenomenon, especially the process from the electric spark bubble to the experimental cylinder starting to contact until the collapse.

[0096] The experimental use environment of the present invention is as shown in the attached Figures 5 to 7 As shown, the experimental water tank 12 is made of transparent glass to ensure that the light emitted by the light source 10 can pass through the experimental water tank, and at the same time, the high-speed camera 13 collects the movement of objects in the experimental water tank; during the experiment, the experimental water tank is placed on the experimental bracket and fixed. The light source and the high-speed camera are placed on both sides of the experimental water tank. The light source is 0.5 meters away from the wall of the experimental water tank. The high-speed camera is 0.5 meters away from the wall of the experimental water tank. The center of the light source is at the same height as the high-speed camera. The experimental table is placed about 2 meters away from the experimental water tank. The data acquisition instrument and the high-voltage control box are placed on the experimental table.

[0097] The experimental bracket 11 is composed of aluminum profiles, which are connected by bolts and angle brackets. The experimental bracket 11 is 1.5m high and 0.78m wide. The overall frame of the bracket is composed of 4 1.5m and 8 0.7m aluminum profiles. The water tank platform is made of 7 0.7m long aluminum profiles and is installed in the lower part of the overall structure of the experimental bracket. The upper platform is 0.5m above the ground.

[0098] During the experiment, the experimental water tank 12 is installed and fixed on the water tank platform of the experimental bracket 11; the experimental water tank 12 is adjusted to be in the middle position; the crossbeam 16 is fixed on the experimental bracket 11; the structural frame 6 and the crossbeam 16 are fixed by bolts; the height of the structural frame 6 is adjusted so that the experimental cylindrical body is in the center position below the horizontal plane in the experimental water tank 12; the distance between the discharge needle 19 and the two experimental cylinders is adjusted; the discharge needle 19 discharges to generate electric sparks, thereby causing the discharge needle 19 in the experimental water tank 12 to generate bubbles, and the bubbles are coupled with the first experimental cylinder 9 or the second experimental cylinder 1, and interact with each other. Under the interaction, the second experimental cylinder 1 moves along the Z direction, and the first experimental cylinder 9 does not move; at the same time, the bubbles pulsate and collapse; the high-speed camera 13 shoots the entire experimental process, and the signal acquisition instrument 14 stores the video file of the experimental process.

[0099] The high-speed camera 13 is matched with the signal acquisition device 14 to capture the contact process between the electric spark bubble and the experimental cylinder, simulating the attack process of the anti-underwater unmanned system, and providing an experimental basis for analyzing the near-field bubble pulsation and load characteristics of the cylindrical surface boundary under different attack angles and different explosion distances.

[0100] Relying on the images captured by the high-speed camera 13, an image processing program is developed by secondary programming to read the video frame by frame and convert it into a grayscale image; Gaussian blur is applied to smooth the image, and then the contours of bubbles and small-sized and small-mass targets are obtained through edge detection and binary filling.

[0101] Extract features from each connected area of ​​the bubble, such as the maximum diameter (radius) and filling degree; after the bubble reaches the maximum radius, check the moment when the filling degree is lower than 0.3 to detect bubble rupture; draw the change curves of the bubble radius and filling degree; output the rupture time (in milliseconds) on the console; calculate according to the bubble radius change rate, the expansion speed is a positive value, and the contraction speed is a negative value, and obtain: the bubble radius change curve over time, the bubble expansion speed change curve over time, the bubble longitudinal position and longitudinal speed change curve over time; automatically identify the bubble movement form and bubble load, realize non-contact measurement of the bubble parameters, and identify the first and second pulsating bubble load change rules with distance parameters.

[0102] Extract feature points from each connected area of ​​small-sized and small-mass targets, automatically identify the motion form of small-sized and small-mass targets, and automatically output the motion parameters (including displacement, velocity, acceleration, etc.) of small-sized and small-mass targets.

[0103] The experimental device of the present invention has a simple structure, is suitable for small-size and small-mass targets, has replaceable mechanism parts that are interchangeable with each other, is easy to assemble and disassemble, is simple to operate, and can conveniently carry out multiple repeated experiments.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An experimental device for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets, characterized by: It comprises a slot plate (3), an experimental support (11), an experimental water tank (12), a high-voltage electric control box (15), an electric spark base (17), a first experimental cylinder mounting mechanism, and a second experimental cylinder mounting mechanism; The groove plate (3) is provided with a positioning opening (32) and two notches (31), and the positioning opening (32) is located between the two notches (31); the experimental water tank (12) is installed in the experimental support (11), a crossbeam (16) is installed on the top of the experimental support (11), and a structural frame (6) extending in a vertical direction is provided on the crossbeam (16); the electric spark base (17) is installed in the experimental water tank (12), a discharge needle column (18) is installed on the electric spark base (17), and a discharge needle column (18) is installed on the upper end of the discharge needle column (18). A discharge needle (19) is provided; a light source (10) and a high-speed camera (13) are provided on both sides of the experimental support (11); the high-speed camera (13) is matched with a signal acquisition instrument (14) to capture the contact process between the electric spark bubble and the experimental cylinder; the high-voltage electric control box (15) is connected to the discharge needle (19) through a wire, and is connected to the high-speed camera (13) and the signal acquisition instrument (14) through a synchronous sensor to ensure that the high-voltage electric control box (15), the high-speed camera (13) and the signal acquisition instrument (14) work synchronously; The first experimental cylinder installation mechanism comprises a first experimental cylinder (9) and two sets of sliding positioning plates (7), the spacing between the two sets of sliding positioning plates (7) is adapted to the first experimental cylinder (9), and the upper end of the first experimental cylinder (9) is fixed to the lower ends of the two sets of sliding positioning plates (7); The second experimental cylinder installation mechanism comprises a second experimental cylinder (1) and two groups of slides, the spacing between the two groups of slides being adapted to the second experimental cylinder (1); the slide comprises an upper annular installation opening (71) and a lower slide rail (2); and the two ends of the second experimental cylinder (1) are respectively arranged in the lower slide rails (2) of the slides on both sides.

2. An experimental method based on the experimental device for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets as described in claim 1, characterized in that: The following steps are involved: Step 1: Designing a first experimental cylinder (9) and a second experimental cylinder (1) according to the goal of small size and small mass; The first experimental cylinder (9) is a complete cylinder, and the second experimental cylinder (1) has sliding grooves at both ends, and the radius and mass of the first experimental cylinder (9) and the second experimental cylinder (1) are equal; Step 2: Arrange the slot plate (3) vertically and install it on the lower end of the structural frame (6). After adjusting the spacing between the two sets of sliding positioning pieces (7), fix the upper end of the first experimental cylinder (9) to the lower ends of the two sets of sliding positioning pieces (7), and fix the upper ends of the two sets of sliding positioning pieces (7) in the notches (31) of the slot plate (3); Step 3: Pour water into the experimental water tank (12), adjust the longitudinal position of the electric spark base (17) according to the experimental content, so that the first experimental cylinder (9) and the discharge needle (19) are located below the water surface, and the distance between the first experimental cylinder (9) and the discharge needle (19) meets the experimental requirements; adjust the light source (10) and the high-speed camera (13) so that the illumination intensity of the light source (10) meets the experimental requirements, and make the shooting positions of the light source (10) and the high-speed camera (13) and the discharge needle (19) on the same horizontal line; Step 4: Start the experiment of the first experimental cylinder (9), make the underwater discharge needle (19) generate underwater bubbles through the high-voltage electric control box (15), and the high-speed camera (13) and the signal acquisition instrument (14) work synchronously; Step 5: Unload the first experimental cylinder (9), the sliding positioning sheet (7) and the slot plate (3); arrange the slot plate (3) horizontally and install it on the lower end of the structural frame (6); insert the upper annular mounting openings (71) of the two sets of sliding sheets into the two slots (31) of the slot plate (3) through the positioning slider (4); adjust the spacing between the two sets of sliding sheets by sliding the positioning slider (4); then place the left and right ends of the second experimental cylinder (1) in the lower slide rails (2) of the sliding sheets on both sides; and fix the two sets of positioning sliders (4) in the positioning openings (32) of the slot plate (3); Step 6: Adjust the water level in the experimental water tank (12), the initial position and distance between the second experimental cylinder (1) and the discharge needle (19), the light source (10) and the shooting position of the high-speed camera (13), consistent with step 3; Step 7: Start the experiment of the second experimental cylinder (1), and use the high-voltage electric control box (15) to make the underwater discharge needle (19) generate the same underwater bubbles as in step 4. The second experimental cylinder (1) moves in the vertical direction along the lower slide rails (2) of the slides on both sides under the action of the bubble explosion, and the high-speed camera (13) and the signal acquisition instrument (14) work synchronously; Step 8: Process the video captured by the high-speed camera (13) frame by frame, convert each frame into a grayscale image, apply Gaussian blur to smooth the image, and then obtain the contours of the bubble and the first experimental cylinder (9) and the second experimental cylinder (1) through edge detection and binary filling; Features are extracted from each connected area of ​​the bubble contour, and the variation law of the bubble pulsation speed with the distance parameter in the two experiments is obtained based on the image size and proportional size; feature points are extracted from each connected area of ​​the first experimental cylinder (9) and the second experimental cylinder (1), the displacement of the second experimental cylinder (1) is identified, and the Hurst index of the displacement time series is calculated based on the re-scaled range analysis method. The nonlinear motion law of the second experimental cylinder (1) is obtained based on the Hurst index, and the experiment of the attack effect of underwater near-field explosion on small-sized and small-mass targets is completed.

3. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized in that: In step 2, the trough plate (3) is arranged vertically and fixed to the lower end of the structural frame (6) by bolts at the four corners.

4. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized in that: In step 2, the upper end of the sliding positioning piece (7) is respectively fixed in two notches (31) on the slot plate (3) by means of positioning bolts (20).

5. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized by: In step 2, the upper end of the first test cylinder (9) is fixed to the lower end of the sliding positioning plate (7) by means of an eyelet screw (8).

6. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized by: In step 5, the trough plate (3) is arranged horizontally and fixed to the lower end of the structural frame (6) through corner brackets (5) at the four corners.

7. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized by: In step 5, mounting holes are provided on both sides of the upper portion of the annular mounting opening (71) of the slide, and are connected to both sides of the lower portion of the positioning slide block (4) by bolts.

8. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized by: In step 5, the two sets of positioning slide blocks (4) are fixed in the positioning openings (32) of the slot plate (3) by means of locking bolts (21).

9. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2 is characterized by: In the step 8, features are extracted from each connected area of ​​the bubble contour. After the bubble reaches the maximum radius, the moment when the filling degree is lower than 0.3 is checked as the bubble rupture moment, and the change curve of the bubble radius and the filling degree is plotted; the expansion speed is defined as a positive value and the contraction speed is defined as a negative value, and the bubble radius variation curve over time, the bubble expansion speed variation curve over time, and the bubble longitudinal position and longitudinal speed variation curve over time are plotted to obtain the variation law of the bubble pulsation speed with the distance parameter in the two experiments.

10. The experimental method for exploring the attack effect of underwater near-field explosion on small-sized and small-mass targets according to claim 2, characterized in that: The Hurst exponent of the displacement time series calculated based on the rescaled range analysis method in step 8 is specifically: Based on the rescaled range analysis method, the mean of the time series is calculated. The time series X={X1,X2,…,X N }, where N represents the length of the sequence, and X represents the time series of displacement, velocity, and acceleration. First, the mean of the time series is calculated: Calculate the deviation sequence Y i for: Calculate the cumulative deviation sequence Z i : The range of the cumulative deviation series is defined as: R(N)=max(Z1,Z2,…,Z N )-min(Z1,Z2,…,Z N ) That is, calculate the difference between the maximum and minimum values ​​of the Z sequence; The standard deviation S(N) of the time series X is: According to the rescaled range analysis method, the relationship between the rescaled range R / S and the time scale N obeys a power law relationship: Taking the logarithm, both sides become a linear relationship: Through linear regression, the slope H value is obtained, which is the Hurst index.

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