Method for measuring penetration track of closed multilayer target

Abstract

The invention relates to a method for measuring the penetration track of a closed multi-layer target, which is used for solving the technical problem that the penetration track in the closed multi-layer target cannot be obtained by the existing method for recording the penetration track of a projectile body on the side surface of a multi-layer target plate by using a camera. The interior of the closed multi-layer target is scanned through the laser radar, the original point cloud data of the bullet hole and the color panoramic image in the bullet hole can be rapidly obtained, the overall penetration situation in the target can be observed, and a macroscopic view angle is provided for researching the penetration effect of the bullet body. According to the invention, the three-dimensional edge points of each layer of bullet hole are projected into the two-dimensional convex polygon, so that the contour and the area of each layer of bullet hole are accurately measured, and the safety risk of manual measurement is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for measuring the penetration trajectory of a target, in particular to a method for measuring the penetration trajectory of a closed multi-layer target. BACKGROUND

[0002] Multi-layer targets are often used to study the penetration performance of a projectile. Measuring the trajectory of the projectile in the multi-layer target can provide important data support for studying the penetration performance of the projectile. After the projectile penetrates the multi-layer target, a bullet hole is formed on each layer of the target plate. The bullet hole position can be used to reverse the trajectory of the projectile. In the existing multi-layer target test, individual target plates are usually erected at equal intervals on the ground to form a multi-layer target. A camera is arranged on the side of the target plate. When the projectile penetrates, the penetration process is recorded by the camera to obtain the penetration trajectory of the projectile. The penetration trajectory recorded by the camera is a two-dimensional trajectory in a single direction.

[0003] In large-scale tests, the multi-layer target is usually closed on the outside and has multiple target plates inside. For a closed multi-layer target, it is not possible to use a camera to record the penetration process in real time when the projectile penetrates. After the projectile penetrates, the position of the projectile penetrating the first layer of target plates can be measured, but it is difficult to measure the position of the bullet hole on each layer of target plates inside the target. Therefore, it is difficult to obtain the penetration trajectory of the closed multi-layer target. SUMMARY

[0004] The present application aims to solve the technical problem that the method of recording the penetration trajectory of a projectile by using a camera on the side of a multi-layer target plate in the prior art cannot obtain the penetration trajectory of a projectile inside a closed multi-layer target, and to provide a method for measuring the penetration trajectory of a closed multi-layer target.

[0005] To solve the above technical problems, the technical solution provided by the present application is as follows:

[0006] A method for measuring the penetration trajectory of a closed multi-layer target, characterized in that it comprises the following steps:

[0007] 1) Use a laser radar to obtain the original point cloud data and color panoramic image inside the closed multi-layer target after penetration, wherein the laser radar is provided with a visible light camera;

[0008] 2) Import the original point cloud data and color panoramic image on each layer of target plate into the corresponding processing software of the laser radar to generate a color three-dimensional point cloud model of the closed multi-layer target;

[0009] 3) Import the color three-dimensional point cloud model into a 3D point cloud processing software to calculate the area of the bullet hole on a single layer of target plate:

[0010] 3.1) Select n three-dimensional edge points around the bullet hole on a single layer of target plate in the color three-dimensional point cloud model, and record the coordinates P of the three-dimensional edge pointsi (x i ,y i ,z i ), where i = 1, ..., n; project the three-dimensional edge points onto a two-dimensional coordinate system to form a closed convex polygon corresponding to the bullet hole; the coordinates of the n vertices of the closed convex polygon are as follows: P1 ′ (x1 ′ ,y1 ′ P2 ′ (x2 ′ ,y2 ′ ), ...P i ′ (x i ′ ,y i ′ ...,P n ′ (x ′ n ,y n ′ ); where n≥3;

[0011] 3.2) Calculate the area S of the closed convex polygon, i.e. the area of ​​the bullet hole on a single-layer target plate, based on the coordinates of the n vertices of the closed convex polygon.

[0012] 4) Calculate the centroid P of the bullet hole on the single-layer target plate. c (x c y c , z c ):

[0013] 4.1) Calculate the average point of the n vertices of the closed convex polygon, and divide the closed convex polygon into n triangles using the average point as a common vertex, and calculate the area S of each triangle. i ;

[0014] 4.2) Based on the area S of the closed convex polygon obtained in step 3.2, calculate the centroid P of the bullet hole using the following formula. c (x c y c , z c ):

[0015]

[0016]

[0017]

[0018] 5) Using the same method as steps 3 and 4, calculate the centroid coordinates of the bullet holes on each target plate;

[0019] 6) According to the centroid coordinates of the bullet hole on each layer target plate obtained in step 5, connect multiple centroids layer by layer to form the penetration trajectory of the projectile body in the closed multilayer target, and complete the measurement of the penetration trajectory.

[0020] Further, the step 1 is specifically:

[0021] 1.1) According to the specific damage inside the closed multilayer target, plan the placement position and scanning route of the laser radar on each layer target plate, the placement position includes multiple placement sites, and the multiple placement sites jointly form a scanning route, which requires that the scanning route can cover the bullet hole area on each layer target plate;

[0022] 1.2) Using the laser radar, respectively scanning each layer target plate according to the placement site and scanning route planned in step 1.1, after the scanning of a station is completed, moving the laser radar to the next station according to the scanning route to start scanning, completing all scanning of the planned scanning route on each layer target plate; while scanning at each station, use the visible light camera to obtain the color panoramic image on each layer target plate; after each layer scanning is completed, the laser radar automatically obtains the original point cloud data of the bullet hole on each layer target plate and the color panoramic image corresponding to the multiple placement sites.

[0023] Further, the step 2 is specifically:

[0024] 2.1) Import the original point cloud data and multiple color panoramic images on each layer target plate into the processing software corresponding to the laser radar, filter, splice and render the original point cloud data on each layer target plate;

[0025] 2.2) Use multiple color panoramic images to color the original point cloud data processed in step 2.1 to obtain a color three-dimensional point cloud model of the closed multilayer target.

[0026] Further, the step 4.1 is specifically:

[0027] 4.1.1) Calculate the coordinates of the average point P0(x0, y0) of the n vertices of the closed convex polygon:

[0028]

[0029]

[0030] 4.1.2) Divide the closed convex polygon into n triangles with the average point P0(x0, y0) as the common vertex, and use vector product to calculate the area S of each triangle i .

[0031] Further, the step 3.2 is specifically:

[0032]

[0033] Further, in step 1.2, the laser radar scans with adjacent placement stations, and there is an overlapping area in the scanning area; and the laser radar is fixed during single-station scanning.

[0034] Further, in step 1, the laser radar is Z+F IMAGER5016; and in step 2, the corresponding processing software is Z+FLaserControl. The corresponding processing software refers to the processing software used by the laser radar manufacturer or specified for use.

[0035] Further, in step 3, the 3D point cloud processing software is CloudCompare.

[0036] Compared with the prior art, the present application has the following beneficial effects:

[0037] 1. The present application is a kind of closed multi-layer target penetration trajectory measurement method, which scans the inside of closed multi-layer target by laser radar, can quickly obtain the original point cloud data of bullet hole and the color panoramic image inside, is used to observe the overall penetration of target inside, provides macroscopic perspective for studying projectile penetration effect.

[0038] 2. The present application is a kind of closed multi-layer target penetration trajectory measurement method, which projects three-dimensional edge points of each layer of bullet hole into two-dimensional convex polygon, thereby accurately measuring the profile and area of bullet hole of each layer, and reducing the safety risk of manual measurement.

[0039] 3. The present application is a kind of closed multi-layer target penetration trajectory measurement method, which obtains the motion trajectory of projectile in the inside of closed target by calculating the centroid coordinates of each layer of bullet hole and connecting the centroid of multi-layer bullet hole, compared with the single-direction two-dimensional motion trajectory obtained by using camera to record, the present application can finally obtain three-dimensional motion trajectory through modeling.

[0040] 4. The present application is a kind of closed multi-layer target penetration trajectory measurement method, which can obtain color panoramic image by visible light camera while laser radar records original point cloud data of bullet hole, colors the original point cloud data, and the colored projectile motion trajectory is clearer and easier to distinguish. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is the structural schematic view of laser radar set in closed multi-layer target in step 1 of the present application, a kind of closed multi-layer target penetration trajectory measurement method embodiment;

[0042] Figure 2 It is the schematic view of three-dimensional edge points being projected to two-dimensional coordinate system in step 3 of the present application, a kind of closed multi-layer target penetration trajectory measurement method embodiment;

[0043] Figure 3 This is a schematic diagram of step 4.1 of an embodiment of the method for measuring the penetration trajectory of a closed multi-layer target according to the present invention, in which the closed convex polygon is divided into n triangles;

[0044] Explanation of reference numerals in the attached figures:

[0045] 1-LiDAR, 2-Target plate, 3-Bullet hole. Detailed Implementation

[0046] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0047] This invention provides a method for measuring the penetration trajectory of a closed, multi-layered target. After the projectile penetrates the target, a lidar 1 is used to scan the interior of the target. The test building in a large-scale test is abstracted as a closed, multi-layered target, such as... Figure 1 The diagram shows a structural schematic of a closed multi-layered target. The target comprises multiple exterior surfaces, which are assembled in a closed manner to form a cube. Multiple target plates 2 are arranged parallel to each other inside the cube. After a projectile penetrates the target plate 2, a bullet hole 3 is formed in the plate 2. A lidar 1 is located inside the closed multi-layered target and includes a visible light camera.

[0048] Specifically, the following steps are included:

[0049] 1) Use LiDAR 1 to acquire raw point cloud data and color panoramic images of the interior of a closed, multi-layered target after penetration:

[0050] 1.1) Based on the specific damage situation inside the closed multi-layer target, the placement position and scanning route of the lidar 1 on each target plate 2 are planned. The placement position includes multiple placement stations set around the edge of the bullet hole. Multiple placement stations together form the scanning route. The scanning route is required to cover the bullet hole 3 area on each target plate 2. The scanning field of view and maximum effective distance of the lidar 1 are comprehensively considered to avoid blind spots. In this embodiment, the lidar 1 adopts Z+FIMAGER5016.

[0051] 1.2) Using the laser radar 1, the placement site and the scanning route planned in step 1.1 are respectively scanned on each layer of target plate 2. After the scanning at each station is completed, the laser radar 1 moves to the next station according to the scanning route to start scanning, until all the scanning routes planned on each layer of target plate 2 are completed. While scanning at each station, the visible light camera on the laser radar automatically rotates a circle to obtain a color panoramic image on each layer of target plate 2. After the scanning of each layer is completed, the laser radar 1 automatically obtains the original point cloud data of the bullet hole 3 on each layer of target plate 2, and the color panoramic images corresponding to multiple placement sites. When the laser radar 1 scans at adjacent placement sites, there is an overlapping area in the scanning area. The laser radar 1 is fixed during single-station scanning, and there is no personnel activity around.

[0052] 2) The original point cloud data and color panoramic images on each layer of target plate 2 are imported into the processing software corresponding to the laser radar 1 to generate a color three-dimensional point cloud model of the closed multi-layer target, specifically:

[0053] 2.1) The original point cloud data and color panoramic images on each layer of target plate 2 obtained in step 1.2 are imported into the processing software corresponding to the laser radar 1, and the original point cloud data on each layer of target plate 2 is filtered, spliced and rendered. In this embodiment, the processing software corresponding to the laser radar 1 is Z+FlaserControl.

[0054] 2.2) Use multiple color panoramic images to color the original point cloud data processed in step 2.1 to obtain a color three-dimensional point cloud model of the closed multi-layer target.

[0055] 3) The color three-dimensional point cloud model is imported into a 3D point cloud processing software to calculate the area of the bullet hole 3 on a single layer of target plate 2:

[0056] 3.1) The color three-dimensional point cloud model is imported into a 3D point cloud processing software. In this embodiment, the 3D point cloud processing software is CloudCompare. Use the mouse to roam around the bullet hole 3, manually select n three-dimensional edge points around the bullet hole 3 on the single layer of target plate 2 in the color three-dimensional point cloud model, and record the coordinates P i (x i ,y i ,z i ) of the three-dimensional edge points, where i = 1, …, n; project the three-dimensional edge points to a two-dimensional coordinate system to form a closed convex polygon corresponding to the bullet hole 3, as shown in Figure 2 , the n vertex coordinates of the closed convex polygon are P1 ′ (x1 ′ ,y1 ′ ), P2 ′ (x2 ′ ,y2 ′ ), … Pi ′ (x i ′ ,y i ′ ...,P n ′ (x ′ n ,y n ′ ); where n≥3; in this embodiment n=5;

[0057] 3.2) Based on the coordinates of the n vertices of the closed convex polygon, calculate the area S of the closed convex polygon according to the following formula, that is, the area of ​​the bullet hole (3) on the single-layer target plate (2);

[0058]

[0059] 4) Calculate the center of mass P of the single-layer bullet hole 3. c (x c y c , z c Specifically, it includes the following steps:

[0060] 4.1) Calculate the average point of the n vertices of the closed convex polygon, and divide the closed convex polygon into n triangles using the average point as a common vertex, and calculate the area S of each triangle. i Specifically:

[0061] 4.1.1) Calculate the coordinates of the average point P0(x0,y0) of the n vertices of the closed convex polygon:

[0062]

[0063]

[0064] 4.1.2) Using the average point P0(x0,y0) as a common vertex, divide the closed convex polygon into n triangles, as follows: Figure 3 As shown; the area S of each triangle is calculated using the vector product. i ;

[0065] 4.2) Based on the area S of the closed convex polygon obtained in step 3.2, the centroid P of bullet hole 3 is calculated using the following formula. c (x c y c , z c ):

[0066]

[0067]

[0068]

[0069] 5) Using the same method as steps 3 and 4, the centroid coordinates of the hole 3 on each layer of the target plate 2 are calculated;

[0070] 6) According to the centroid coordinates of the hole 3 on each layer of the target plate 2 obtained in step 5, the multiple centroids are connected layer by layer to form the penetration trajectory of the projectile in the closed multi-layer target, and the measurement of the penetration trajectory is completed.

[0071] The present application establishes a color three-dimensional point cloud model for the hole 3 in the closed multi-layer target, selects three-dimensional edge points around the hole, and projects them into a two-dimensional closed convex polygon; the centroid of the hole is calculated according to the closed convex polygon, and the multiple centroids are connected, which can effectively measure the three-dimensional movement trajectory of the projectile after penetration in the multi-layer target, and also obtain the damage area on each layer of the target plate 2.

Claims

1. A method of measuring a closed multi-layer target penetration trajectory, characterized in that, The method comprises the following steps: 1) Obtain the original point cloud data and color panoramic image inside the closed multilayer target after penetration by using a laser radar (1) with a visible light camera; 2) Import the original point cloud data and color panoramic image on each target plate (2) into the corresponding processing software of the laser radar (1) to generate a color three-dimensional point cloud model of the closed multilayer target; 3) Import the color three-dimensional point cloud model into a 3D point cloud processing software to calculate the area of the bullet hole (3) on the single target plate (2): 3.1) Select n three-dimensional edge points around the bullet hole (3) on the single-layer target plate (2) in the colored three-dimensional point cloud model, and record the coordinates P of the three-dimensional edge points. i (x i ,y i ,z i ), where i = 1, ..., n; project the three-dimensional edge points onto the two-dimensional coordinate system to form a closed convex polygon corresponding to the bullet hole (3); the coordinates of the n vertices of the closed convex polygon are as follows: P1 ′ (x1 ′ ,y1 ′ P2 ′ (x2 ′ ,y2 ′ ), ...P i ′ (x i ′ ,y i ′ ...,P n ′ (x ′ n ,y n ′ ); where n≥3; 3.2) Calculate the area S of the closed convex polygon according to the coordinates of the n vertices of the closed convex polygon, that is, the area of the bullet hole (3) on the single target plate (2); 4) calculating the center of mass P of the hole (3) on the single target plate (2) c (x c , y c , z c ): 4.1) Calculate the average point of the n vertices of the closed convex polygon, divide the closed convex polygon into n triangles with the average point as the common vertex, and calculate the area S of each triangle i ; 4.2) The area S of the closed convex polygon obtained according to step 3.2 is used to calculate the mass center P of the hole (3) according to the following formula c (x c , y c , z c ) : 5) Calculate the centroid coordinates of the bullet hole (3) on each target plate (2) by the same method as steps 3 and 4; 6) Connect the centroids layer by layer according to the centroid coordinates of the bullet hole (3) on each target plate (2) obtained in step 5 to form the penetration trajectory of the projectile in the closed multilayer target, and complete the measurement of the penetration trajectory.

2. The method of claim 1, wherein, The step 1 is specifically: 1.1) According to the specific damage inside the closed multilayer target, plan the placement position and scanning route of the laser radar (1) on each target plate (2), the placement position comprises a plurality of placement sites, and the plurality of placement sites jointly form a scanning route, which requires that the scanning route can cover the bullet hole (3) area on each target plate (2); 1.2) Use the laser radar (1) to respectively scan each target plate (2) according to the placement sites and scanning route planned in step 1.1, after the scanning of a station is completed, move the laser radar (1) to the next station according to the scanning route to start scanning, and complete all scanning of the planned scanning route on each target plate (2); while scanning at each station, use the visible light camera to obtain the color panoramic image on each target plate (2); after each layer of scanning is completed, the laser radar (1) automatically obtains the original point cloud data of the bullet hole (3) on each target plate (2) and the color panoramic image corresponding to the plurality of placement sites.

3. The method of measuring the trajectory of a closed multi-layer target according to claim 1 or 2, characterized in that, The step 2 is specifically: 2.1) Import the original point cloud data and a plurality of color panoramic images on each target plate (2) into the corresponding processing software of the laser radar (1) to filter, splice and render the original point cloud data on each target plate (2); 2.2) Color the original point cloud data processed in step 2.1 using a plurality of color panoramic images to obtain a color three-dimensional point cloud model of the closed multilayer target.

4. The method according to claim 3, wherein the step 4.1 is specifically: 4.1.1) Calculate the coordinates of the average point P0(x0, y0) of the n vertices of the closed convex polygon: 4.1.2) Split the closed convex polygon into n triangles using the average point P0(x0,y0) as common vertex, calculate the area S of each triangle using the vector product i .

5. The method of claim 3, wherein, The step 3.2 is specifically:

6. The method according to claim 5, wherein: In step 1.2, there is an overlapping area in the scanning area when the laser radar (1) scans adjacent placement sites; and the laser radar (1) is fixed during single station scanning.

7. The method of measuring the trajectory of a closed multi-layer target according to claim 6, characterized in that: In step 1, the laser radar (1) is Z+F IMAGER 5016; in step 2, the corresponding processing software is Z+FLaserControl.

8. The method of measuring the trajectory of a closed multi-layer target according to claim 7, characterized in that: In step 3, the 3D point cloud processing software is CloudCompare.

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