A device and method for measuring three-dimensional deformation field of a projectile body in a penetration process

Abstract

The application discloses a kind of three-dimensional deformation field measuring device and measuring method of projectile body in penetration process, it is related to projectile body penetration test technical field, its technical solution key points are: including: light gas gun, for launching solid projectile;Special target store, its lateral wall is equipped with observation window, inside is equipped with target plate and the projectile to be measured fixed on target plate;Three-dimensional digital image acquisition equipment, symmetrically arranged outside observation window, including two high-speed cameras of synchronous trigger, matching lens, high-brightness light source and synchronous trigger;Magnetic speed measuring instrument, set in the tail of the barrel of light gas gun;Data processing equipment is used to receive the image sequence collected by three-dimensional digital image acquisition equipment, based on calibration parameter calculation the three-dimensional displacement field of the surface of the projectile to be measured, full-field strain field and velocity field, visual output deformation evolution process.The application can realize the non-contact, high space-time resolution measurement of three-dimensional dynamic deformation field of projectile body itself in the transient process of projectile body penetrating target plate.

Description

Technical Field

[0001] This invention relates to the field of projectile penetration testing technology, and more specifically, to a device and method for measuring the three-dimensional deformation field of a projectile during penetration. Background Technology

[0002] In fields such as defense technology, aerospace, and protective engineering, studying the mechanical behavior of projectiles penetrating targets is crucial. Traditional research methods, such as high-speed photography, post-target observation, and analysis of recovered projectiles, primarily focus on macroscopic results such as penetration depth and target failure modes, or can only obtain two-dimensional projection images of the projectile. They cannot acquire continuous, dynamic, and full-field deformation data of the projectile's surface morphology during penetration, especially for non-transparent projectiles. This data is crucial for verifying and refining material constitutive models and for numerical simulations of armor-piercing theory. Currently, there is a lack of a systematic method that can perform high-precision measurements of projectiles during penetration experiments and successfully obtain their three-dimensional deformation field. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the purpose of this invention is to provide a device and method for measuring the three-dimensional deformation field of a projectile during penetration, which enables non-contact, high spatiotemporal resolution measurement of the projectile's own three-dimensional dynamic deformation field during the transient process of the projectile penetrating the target plate.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution:

[0005] Firstly, a device for measuring the three-dimensional deformation field of a projectile during penetration is provided, comprising:

[0006] Light air cannon, used to fire solid shot;

[0007] A dedicated target compartment has observation windows on its side walls and a target plate and a test projectile fixed to the target plate inside. The solid projectile impacts the head of the test projectile to simulate the process of the projectile hitting the target plate.

[0008] A three-dimensional digital image acquisition device is symmetrically arranged outside the observation window, including two synchronously triggered high-speed cameras, matching lenses, high-brightness light sources and synchronous triggers;

[0009] A magnetic velocity meter is installed at the tail of the barrel of the light air gun to detect the firing of the solid projectile and output a trigger signal.

[0010] The data processing device is used to receive the image sequence acquired by the three-dimensional digital image acquisition device, calculate the three-dimensional displacement field, full-field strain field and velocity field of the surface of the projectile under test based on the calibration parameters, and visualize the deformation evolution process.

[0011] The synchronization trigger is connected to the magnetic velocimeter and the three-dimensional digital image acquisition device to establish a synchronization trigger chain.

[0012] Furthermore, the surface of the test projectile is coated with a matte background coating;

[0013] Furthermore, the coating is fabricated with randomly distributed micro-nano scale speckle patterns.

[0014] Furthermore, the speckle pattern consists of randomly distributed black spots printed on a white matte high-temperature resistant ceramic varnish substrate using black high-temperature resistant ink.

[0015] Furthermore, the input terminal of the synchronous trigger is communicatively connected to the magnetic speed measuring instrument to receive the trigger signal output by the magnetic speed measuring instrument;

[0016] Furthermore, the output of the synchronization trigger is communicatively connected to the two high-speed cameras and the data processing device, respectively, for synchronously sending the trigger signal to the two high-speed cameras to start image acquisition, and sending a coordination signal to the data processing device to synchronize its operation with the three-dimensional digital image acquisition device.

[0017] Furthermore, the frame rate of the two high-speed cameras is no less than 100,000 frames per second;

[0018] The accompanying lens is a microscope lens or a telephoto lens;

[0019] In addition, the high-brightness light source is used to provide clear illumination for microsecond-level exposure times.

[0020] Secondly, a method for measuring the three-dimensional deformation field of a projectile during penetration is provided. This method is used in the three-dimensional deformation field measuring device for a projectile during penetration as described in any one of the first aspects, and includes the following steps:

[0021] The test area on the surface of the projectile is processed and a speckle pattern is prepared.

[0022] The three-dimensional calibration plate is placed at the installation position of the projectile to be tested, and the three-dimensional digital image acquisition device is spatially calibrated to obtain the calibration parameters;

[0023] The penetration process is simulated by firing solid projectiles from the light air gun to impact the head of the test projectile.

[0024] The launch of the solid projectile is detected by the magnetic velocity measuring instrument and a trigger signal is output. The synchronous trigger activates two high-speed cameras to acquire image sequences of speckle patterns on the surface of the projectile under test.

[0025] The image sequence is imported into the data processing device, and the three-dimensional displacement field, full-field strain field and velocity field of the surface of the projectile under test are calculated based on the calibration parameters. The deformation evolution process is then visualized and output.

[0026] Furthermore, the process of processing the test area on the surface of the projectile and preparing a speckle pattern includes:

[0027] The head and cylindrical test area of ​​the projectile to be tested are polished, cleaned, and degreased.

[0028] A coating with a matte white high-temperature resistant ceramic paint is sprayed to create a matte background.

[0029] Additionally, black high-temperature resistant ink is used to print randomly distributed black spots on the coating as a speckle pattern.

[0030] Furthermore, the spatial calibration of the three-dimensional digital image acquisition device includes:

[0031] The three-dimensional calibration plate is controlled to perform translation and rotation movements in space at least 12 different poses, and the three-dimensional digital image acquisition device synchronously acquires images of each pose;

[0032] Furthermore, the calibration parameters include camera parameters and 3D reconstruction parameters.

[0033] Furthermore, the method also includes:

[0034] Adjust the illumination angle and intensity of the high-brightness light source to acquire images with microsecond-level exposure times.

[0035] Furthermore, the calculation of the three-dimensional displacement field, full-field strain field, and velocity field of the surface of the projectile under test based on the calibration parameters specifically includes:

[0036] Based on the calibration parameters, stereo matching is performed on the synchronized images of the left and right cameras to reconstruct the three-dimensional point cloud data of the surface of the projectile under test at each moment;

[0037] The motion of speckle is tracked frame by frame to calculate the three-dimensional displacement field, full-field strain field and velocity field of each point on the surface of the projectile under test, and the deformation evolution process is visualized and output.

[0038] The displacement field includes U, V, and W components, and the strain field includes strain components in the x, y, and xy directions.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. This invention simulates the impact process of a projectile hitting a target by impacting the head of a projectile with a solid bullet. It uses a dual-lens three-dimensional digital image acquisition device and, based on the principles of stereo vision and triangulation, realizes the three-dimensional coordinate tracking of the speckle pattern on the surface of the projectile during penetration. For the first time, it realizes the in-situ measurement of continuous, dynamic, and full-field three-dimensional deformation data of the projectile's own surface during penetration, providing a direct basis for verifying the material constitutive model and correcting the armor-piercing theory.

[0041] 2. This invention employs a full-chain synchronous design involving a magnetometry instrument, a synchronous trigger, a camera, and a data processing device. By using the launch time of the solid projectile detected by the magnetometry instrument as the zero point, it ensures strict alignment between camera acquisition, data processing, and the impact process. Simultaneously, the high-speed camera's frame rate of ≥100,000 frames per second, combined with microsecond-level exposure using a high-brightness light source, guarantees clear capture of transient deformations such as head compression and cylindrical buckling during penetration. This achieves high spatiotemporal resolution three-dimensional deformation field measurement, overcoming the limitations of traditional methods in inferring macroscopic results.

[0042] 3. In this invention, the white matte background and black spots form a strong grayscale difference, providing stable feature points for digital image correlation (DIC) analysis; the ceramic paint and ink are resistant to high penetration temperatures, preventing coating melting or speckle peeling; the micro-nano speckles can still maintain clear contours under high strain rate deformation, ensuring frame-by-frame tracking accuracy, guaranteeing the accuracy of three-dimensional displacement field and strain field calculations, and enabling the measurement data to truly reflect the material deformation behavior during projectile penetration.

[0043] 4. This invention performs pixel-level matching of synchronized images from left and right cameras, quantifies parallax, and calculates the three-dimensional coordinates of speckle based on the parallax and baseline distance using the principle of similar triangles. It tracks speckle displacement frame by frame and derives the three-dimensional displacement field, strain field, and velocity field. This can transform complex deformation analysis into an automated algorithm process, realize quantitative calculation and intuitive visualization of full-field deformation data, avoid the errors and inefficiencies of manual analysis, and provide data-image dual-dimensional support for the study of penetration mechanisms. Attached Figure Description

[0044] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0045] Figure 1 This is a schematic diagram of the overall structure of the measuring device in Embodiment 1 of the present invention;

[0046] Figure 2 This is an overall flowchart of the measurement method in Embodiment 2 of the present invention;

[0047] Figure 3 This is a schematic diagram illustrating the principle of dual-lens three-dimensional digital imaging in Embodiment 2 of the present invention.

[0048] The attached diagram shows the markings and corresponding component names:

[0049] 1. Light air cannon; 2. Magnetometer; 3. Solid shot; 4. Dedicated target chamber; 5. Test projectile; 6. High-brightness light source; 7. Synchronization trigger; 8. Three-dimensional digital image acquisition equipment; 9. Target plate; 10. Data processing equipment. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0051] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to that other component.

[0052] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] Example 1: A device for measuring the three-dimensional deformation field of a projectile during penetration, such as... Figure 1 As shown, it includes a light air cannon 1, a dedicated target chamber 4, a three-dimensional digital image acquisition device 8, a magnetic velocimeter 2, and a data processing device 10.

[0055] The light gas cannon 1 serves as the power core, used to launch the solid shot 3. The light gas cannon 1 uses high-pressure gas to drive the solid shot 3 to achieve high-speed motion, providing initial impact kinetic energy for simulating the projectile's impact with the target, and is the power source for the entire experimental system. In some optional examples, a 60cm diameter light gas cannon 1 can be used as a loading device to launch solid shots 3 made of materials such as steel and aluminum to effectively penetrate the target plate 9 in the experiment, thus simulating the process of the projectile penetrating the target plate 9.

[0056] The dedicated target chamber 4 integrates a target plate 9 and the test projectile 5. The target plate 9 serves as a fixed carrier for the test projectile 5, and an observation window is opened on the side wall of the central area of ​​the dedicated target chamber 4. The observation window provides an observation channel for the three-dimensional digital image acquisition device 8. The test projectile 5 is fixed on the target plate 9, with the head of the test projectile 5 facing the light air gun 1. The process of the test projectile 5 being impacted by a solid shot 3 is used to simulate the process of the projectile impacting and penetrating the target plate 9.

[0057] This invention also involves surface treatment of the projectile's head and the cylindrical test area, followed by spraying a high-contrast, high-temperature-resistant coating with a matte background. Micro-nano fabrication, transfer printing, or special sputtering processes can be used to create randomly distributed micro-nano scale speckle patterns on the coating that are resistant to peeling or blurring under high strain rates. Before the experiment, a three-dimensional calibration plate with high-precision markers is placed in the projectile's original position to perform rigorous spatial calibration of the dual-camera system, obtaining high-precision camera parameters and three-dimensional reconstruction parameters.

[0058] In some optional examples, the surface of the test projectile 5 is coated with a matte background layer, such as white matte high-temperature resistant ceramic paint, and then micro-nano-scale speckle patterns are created. For example, black high-temperature resistant ink is used to print randomly distributed black spots on the matte background coating substrate. This design has both "high temperature resistance" and "high recognition" characteristics: the matte ceramic paint and high-temperature resistant ink can resist the high temperature erosion of the penetration process, avoiding speckle peeling or coating deformation; the random black spots form a strong contrast feature against the matte background, providing stable markers for subsequent digital image correlation analysis.

[0059] In this invention, the white matte background and black spots create a strong grayscale difference, providing stable feature points for digital image correlation (DIC) analysis; the ceramic paint and ink are resistant to high penetration temperatures, preventing coating melting or speckle peeling; the micro-nano speckles maintain clear outlines even under high strain rate deformation, ensuring frame-by-frame tracking accuracy and guaranteeing the accuracy of three-dimensional displacement and strain field calculations, so that the measurement data can truly reflect the material deformation behavior during projectile penetration.

[0060] The three-dimensional digital image acquisition device 8 is a dual-lens high-speed three-dimensional digital image correlation (3D-DIC) measurement system. The three-dimensional digital image acquisition device 8 is symmetrically arranged outside the observation window of the dedicated target chamber 4 and consists of two synchronously triggered high-speed cameras, matching lenses, high-brightness light source 6 and synchronous trigger 7.

[0061] The accompanying lens can be a microscope lens or a telephoto lens, adapted according to the size of the test projectile 5 and the observation distance. The frame rate of the high-speed camera is no less than 100,000 frames per second to ensure that the high-speed deformation details of the surface of the test projectile 5 during the penetration process are captured.

[0062] The high-brightness light source 6 provides illumination with microsecond-level exposure times, ensuring image clarity and signal-to-noise ratio under high-speed motion. In some optional examples, the illumination angle and intensity of the high-brightness light source 6 can be adjusted to ensure that the speckle pattern on the surface of the projectile is clearly illuminated without strong reflections within an extremely short exposure time (microseconds).

[0063] The synchronous trigger 7 serves as the system's time synchronization hub. Its input is connected to the magnetic velocimeter 2, and its output is connected to two high-speed cameras and the data processing device 10, respectively.

[0064] This invention employs a full-chain synchronous design of magnetometry 2-synchronization trigger 7-camera-data processing device 10, using the launch time of the solid projectile 3 detected by magnetometry 2 as the zero point of time, ensuring strict alignment between camera acquisition, data processing, and the impact process. Simultaneously, the high-speed camera with a frame rate of ≥100,000 frames / second, combined with the microsecond-level exposure of the high-brightness light source 6, ensures clear capture of transient deformations such as head compression and cylindrical buckling during penetration, achieving high spatiotemporal resolution three-dimensional deformation field measurement and overcoming the limitations of macroscopic result inference by traditional methods.

[0065] The magnetovelocity meter 2 is installed at the breech of the barrel of the light gas gun 1. Its core function is to detect the firing time of the solid shot 3 and output a trigger signal as the zero-point reference for the entire measurement device. By using the magnetovelocity meter 2 as the trigger source, it is possible to ensure that the high-speed camera starts slightly before the interaction between the projectile and the target plate 9 begins, and to record the entire penetration process completely.

[0066] The data processing device 10 receives image sequences acquired by the three-dimensional digital image acquisition device 8. Based on pre-calibrated parameters, such as camera intrinsic and extrinsic parameters and spatial coordinate system transformation relationships, it calculates the three-dimensional displacement field, full-field strain field, and velocity field of the surface of the test projectile 5 using techniques such as digital image correlation (DIC). The deformation evolution process is then output in a visual form to support the analysis and research of the test data. Visualization forms include, but are not limited to, animations, strain contour maps, and velocity-time curves. In some optional examples, the data processing device 10 can be implemented using 3D-DIC analysis software configured in a computer.

[0067] Example 2: A method for measuring the three-dimensional deformation field of a projectile during penetration. This method is used to implement the three-dimensional deformation field measuring device for a projectile during penetration described in Example 1, such as... Figure 2 As shown, the specific steps are as follows.

[0068] (1) Process the test area on the surface of the test projectile 5 and prepare a speckle pattern.

[0069] First, based on the actual working conditions, the material of solid projectile 3 and the structure of projectile 5 to be tested were determined.

[0070] Then, the head and cylindrical test area of ​​the test projectile 5 are polished, cleaned, and degreased to ensure a clean surface; a layer of white matte high-temperature resistant ceramic paint is evenly sprayed onto the test area to form a highly reflective, matte background layer; and black high-temperature resistant ink is used to print randomly distributed black spot patterns on the coating to form a speckled pattern that is firmly attached and can withstand high-speed deformation and friction.

[0071] (2) Place the three-dimensional calibration plate at the installation position of the test projectile 5, perform spatial calibration on the three-dimensional digital image acquisition device 8, and obtain calibration parameters.

[0072] Specifically, a three-dimensional calibration plate is precisely placed at the actual position of the fixed test projectile 5. The focal length, aperture and angle of the dual cameras are adjusted to ensure that the three-dimensional calibration plate is clearly imaged in the center of the field of view. The three-dimensional calibration plate is controlled to perform translation and rotation movements in space at least 12 different poses. The dual cameras simultaneously acquire images of each pose. The final calibration parameters include camera parameters and three-dimensional reconstruction parameters.

[0073] (3) The solid bullet 3 is fired by the light air gun 1 to hit the head of the test projectile 5 to simulate the penetration process.

[0074] Five test projectiles are fixed to the target frame in the target compartment, and three solid shot is loaded into the barrel from the front of the light gas gun 1. After evacuating the dedicated target compartment 4, the firing procedure of the light gas gun 1 is started.

[0075] (4) The solid bullet 3 is launched by the magnetic velocity meter 2 and the trigger signal is output. The synchronous trigger 7 starts two high-speed cameras to collect image sequences of speckle patterns on the surface of the bullet 5 under test.

[0076] The projectile's flight triggers the magnetic velocity meter 2 at the breech of the gun barrel, simultaneously activating two high-speed cameras to record the experimental process.

[0077] In some optional examples, the illumination angle and intensity of the high-brightness light source 6 can be adjusted to acquire images with microsecond-level exposure times.

[0078] (5) Import the image sequence into the data processing device 10, calculate the three-dimensional displacement field, full-field strain field and velocity field of the surface of the test projectile 5 based on the calibration parameters, and visualize the deformation evolution process.

[0079] The three-dimensional displacement field, full-field strain field, and velocity field of the surface of the test projectile 5 are calculated based on the calibration parameters. Specifically, the three-dimensional point cloud data of the surface of the test projectile 5 at each moment is reconstructed by performing stereo matching on the synchronous images of the left and right cameras based on the calibration parameters; the speckle motion is tracked frame by frame to calculate the three-dimensional displacement field, full-field strain field, and velocity field of each point on the surface of the test projectile 5, and the deformation evolution process is visualized and output; wherein, the displacement field includes U, V, and W components, and the strain field includes strain components in the x direction, y direction, and xy direction.

[0080] Specifically, dual-lens 3D digital imaging technology is achieved through binocular stereo vision and is a comprehensive technology based on optical imaging, triangulation, and computer vision algorithms. Its core objective is to recover the 3D geometric information of a scene from two 2D images with relative positional differences. By simulating human eyes, two image sensors with a preset distance are placed on the same horizontal line, thereby capturing two sets of images of the same physical scene from different viewpoints with slight differences. The core principle is that when light passes through the lens group of the dual lenses and forms an image on the photosensitive element, every 3D point in space will generate a corresponding projection point in the left and right 2D images. Due to slight shifts in the viewing angle, these projection points have relative displacement in the horizontal direction. Through high-precision pixel-level matching of the left and right images using computer vision algorithms, the system can capture and quantify this parallax, such as... Figure 3 As shown.

[0081] Suppose there exists a point P in space, with its three-dimensional coordinates (X, Y, Z) in the world coordinate system. This point is projected onto the image plane of the left camera. and the image plane point of the right camera Based on the principle of similar triangles in perspective projection, the coordinate relationships can be derived:

[0082] For the left camera, the origin is located at the left optical center. :

[0083] , ;

[0084] in, It is the focal length.

[0085] For the right camera, its optical center It is offset by a distance B relative to the left camera on the X-axis, so its X-coordinate in the coordinate system is XB:

[0086] , .

[0087] Disparity is defined as the difference d between the x-coordinates of the same point in the left and right images. .

[0088] Solve the projection equations of the left and right cameras simultaneously:

[0089] ;

[0090] This leads to the core formula for calculating depth:

[0091] .

[0092] The formula shows that depth Z is inversely proportional to parallax d. The closer the object is to the camera, the greater the pixel displacement (parallax) in the left and right images; when the object is infinitely far away, the parallax approaches zero.

[0093] In the actual use of DIC, firstly, the focal length f and principal point are obtained through camera calibration. The intrinsic parameters and spatial pose (rotation R and translation T) between the two cameras are calculated. These parameters are then used for stereo correction, aligning images with angular offsets to the same virtual imaging plane, ensuring the epipolar lines of the left and right images are horizontally aligned, thus reducing the matching search range from two dimensions to one dimension. Based on this, the stereo matching algorithm determines disparity by calculating the similarity of pixels in the same row. (That is, the difference in horizontal coordinates of the same point in the left and right images). Finally, based on the geometric mapping relationship of similar triangles and combined with the baseline distance B, the two-dimensional pixels of the image coordinate system can be restored to the true three-dimensional coordinates (X, Y, Z). The core transformation formula is as follows:

[0094] ;

[0095] ;

[0096] .

[0097] This invention performs pixel-level matching of synchronized images from left and right cameras, quantifies parallax, and calculates the three-dimensional coordinates of speckles based on the parallax and baseline distance using the principle of similar triangles. It tracks speckle displacement frame by frame and derives the three-dimensional displacement field, strain field, and velocity field. This can transform complex deformation analysis into an automated algorithm process, realize quantitative calculation and intuitive visualization of full-field deformation data, avoid the errors and inefficiencies of manual analysis, and provide data-image dual-dimensional support for the study of penetration mechanisms.

[0098] Working principle: This invention simulates the impact process of a projectile hitting a target by impacting the head of a test projectile 5 with a solid projectile 3. It uses a dual-lens three-dimensional digital image acquisition device 8, based on the principles of stereo vision and triangulation, to achieve three-dimensional coordinate tracking of the speckles on the surface of the test projectile 5 during penetration. For the first time, it realizes in-situ measurement of continuous, dynamic, and full-field three-dimensional deformation data of the projectile's own surface during penetration, providing direct evidence for verifying the material constitutive model and correcting the armor-piercing theory.

[0099] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for measuring the three-dimensional deformation field of a projectile during penetration, characterized in that, include: Light air gun (1), used to fire solid shot (3); A dedicated target compartment (4) has an observation window on its side wall and a target plate (9) and a test projectile (5) fixed on the target plate (9) inside. The solid projectile (3) strikes the head of the test projectile (5) to simulate the process of the projectile hitting the target plate (9). A three-dimensional digital image acquisition device (8) is symmetrically arranged outside the observation window, including two synchronously triggered high-speed cameras, matching lenses, a high-brightness light source (6) and a synchronous trigger (7); A magnetic velocity meter (2) is installed at the tail of the barrel of the light air gun (1) to detect the firing of the solid projectile (3) and output a trigger signal. The data processing device (10) is used to receive the image sequence acquired by the three-dimensional digital image acquisition device (8), calculate the three-dimensional displacement field, full-field strain field and velocity field of the surface of the projectile (5) under test based on the calibration parameters, and visualize the deformation evolution process. The synchronization trigger (7) is connected to the magnetic velocimeter (2) and the three-dimensional digital image acquisition device (8) to establish a synchronization trigger chain.

2. The device for measuring the three-dimensional deformation field of a projectile during penetration according to claim 1, characterized in that, The surface of the test projectile (5) is coated with a matte background coating; Furthermore, the coating is fabricated with randomly distributed micro-nano scale speckle patterns.

3. The device for measuring the three-dimensional deformation field of a projectile during penetration according to claim 2, characterized in that, The speckle pattern consists of randomly distributed black spots printed on a white matte high-temperature resistant ceramic paint substrate using black high-temperature resistant ink.

4. The device for measuring the three-dimensional deformation field of a projectile during penetration according to claim 1, characterized in that, The input terminal of the synchronous trigger (7) is communicatively connected to the magnetic speed measuring instrument (2) to receive the trigger signal output by the magnetic speed measuring instrument (2); Furthermore, the output of the synchronization trigger (7) is communicatively connected to the two high-speed cameras and the data processing device (10), respectively, and is used to synchronously send the trigger signal to the two high-speed cameras to start image acquisition, and to send a coordination signal to the data processing device (10) to synchronize its operation with the three-dimensional digital image acquisition device (8).

5. The device for measuring the three-dimensional deformation field of a projectile during penetration according to claim 1, characterized in that, The frame rate of the two high-speed cameras is no less than 100,000 frames per second; The accompanying lens is a microscope lens or a telephoto lens; In addition, the high-brightness light source (6) is used to provide clear illumination for microsecond-level exposure times.

6. A method for measuring the three-dimensional deformation field of a projectile during penetration, characterized in that, This method is used in a projectile three-dimensional deformation field measurement device during penetration as described in any one of claims 1-5, and includes the following steps: The test area on the surface of the projectile (5) is processed and a speckle pattern is prepared; The three-dimensional calibration plate is placed at the installation position of the projectile (5) to perform spatial calibration on the three-dimensional digital image acquisition device (8) to obtain the calibration parameters; The penetration process is simulated by firing a solid projectile (3) from the light air gun (1) to impact the head of the test projectile (5); The magnetic velocimeter (2) detects the launch of the solid projectile (3) and outputs a trigger signal. The synchronous trigger (7) activates two high-speed cameras to collect image sequences of speckle patterns on the surface of the projectile (5). The image sequence is imported into the data processing device (10), and the three-dimensional displacement field, full-field strain field and velocity field of the surface of the projectile (5) under test are calculated based on the calibration parameters. The deformation evolution process is visualized and output.

7. The method for measuring the three-dimensional deformation field of a projectile during penetration according to claim 6, characterized in that, The process of processing the test area on the surface of the projectile (5) and preparing a speckle pattern includes: The head and cylindrical test area of ​​the projectile (5) to be tested are polished, cleaned and degreased; A coating with a matte white high-temperature resistant ceramic paint is sprayed to create a matte background. Additionally, black high-temperature resistant ink is used to print randomly distributed black spots on the coating as a speckle pattern.

8. The method for measuring the three-dimensional deformation field of a projectile during penetration according to claim 6, characterized in that, The spatial calibration of the three-dimensional digital image acquisition device (8) includes: The three-dimensional calibration plate is controlled to perform translation and rotation movements in space at least 12 different poses, and the three-dimensional digital image acquisition device (8) synchronously acquires images of each pose; Furthermore, the calibration parameters include camera parameters and 3D reconstruction parameters.

9. The method for measuring the three-dimensional deformation field of a projectile during penetration according to claim 6, characterized in that, The method also includes: Adjust the illumination angle and intensity of the high-brightness light source (6) to acquire images with microsecond-level exposure time.

10. A method for measuring the three-dimensional deformation field of a projectile during penetration according to claim 6, characterized in that, The calculation of the three-dimensional displacement field, full-field strain field, and velocity field of the surface of the test projectile (5) based on the calibration parameters is as follows: Based on the calibration parameters, stereo matching is performed on the synchronized images of the left and right cameras to reconstruct the three-dimensional point cloud data of the surface of the test projectile (5) at each moment; The motion of speckle is tracked frame by frame to calculate the three-dimensional displacement field, full-field strain field and velocity field of each point on the surface of the test projectile (5), and the deformation evolution process is visualized and output. The displacement field includes U, V, and W components, and the strain field includes strain components in the x, y, and xy directions.

Images