System and method for measuring target landing speed of dynamic explosion oblique incidence fragment

Abstract

The invention discloses a system and a method for measuring the target landing speed of a dynamic explosion oblique incidence fragment, and solves the problem that the existing fragment speed measurement method is difficult to be suitable for a dynamic explosion fragment speed measurement scene with a severe environment and an uncertain track. The system specifically comprises a projectile body coordinate resolving module, a double-layer target breaking assembly, a distributed time measuring module, a real-time dynamic positioning instrument and a terminal data processing module. The output end of the projectile body coordinate resolving module is connected with the input end of the terminal data processing module; the output end of the double-layer target breaking assembly is connected with the input end of the distributed time measurement module, and the target surface is in a regular shape; the output end of the distributed time measurement module is connected with the input end of the terminal data processing module; and the output end of the real-time dynamic positioning instrument is connected with the input end of the terminal data processing module. According to the invention, the vertical component of the fragment targeting speed is measured through the low-cost broken target, and the incident angle of the fragment at each point is measured by using the high-speed camera, so that the low-cost measurement of the multi-point oblique incidence fragment targeting speed is realized.

Description

Technical Field

[0001] The present invention relates to a fragment velocity measurement system and method, and particularly to a system and method for measuring the velocity of fragments hitting a target with oblique incidence in dynamic explosion. Background Art

[0002] The core index for measuring the killing ability of dynamic explosion fragments against a target is the velocity of the fragments hitting the target. The velocity of the fragments hitting the target is one of the main measurement items in the experiment of dynamic explosion fragment damage parameters. There are challenges in measuring the velocity of dynamic explosion fragments hitting the target, such as the uncertain flight trajectory of the fragments, the scattered coverage range of the fragments, and the harsh measurement environment. Currently, the commonly used methods for measuring fragment velocity include the double-light screen target method, the radar method, the acoustic method, etc. The double-light screen method measures the flight velocity of fragments using the principle of sectional velocity measurement, and is suitable for static explosion fragment experiments with a determined flight direction, but has problems such as difficult protection and high layout cost. The radar method measures fragments using the principle of electromagnetic wave Doppler and has the advantage of being able to obtain the position-time curve, but its high cost limits its application in large-scale deployment. The acoustic method measures the flight velocity of fragments using the shock wave of the fragments. However, the shock wave of the fragments is easily affected by weather factors and is not very suitable for measuring the velocity of dynamic explosion fragments in the wild. In summary, most of the existing fragment velocity measurement methods are suitable for static explosion experiments with a straight flight trajectory and a single working condition, and are difficult to apply to the measurement scenario of dynamic explosion fragment velocity with a harsh environment, an uncertain trajectory, and numerous measurement points. Therefore, it is necessary to develop a measurement system with low cost, simple layout, and capable of measuring the oblique incidence velocity. Summary of the Invention

[0003] In order to solve the technical problem that the existing fragment velocity measurement methods are difficult to apply to the measurement scenario of dynamic explosion fragment velocity with a harsh environment, an uncertain trajectory, and numerous measurement points, the present invention provides a system and method for measuring the velocity of fragments hitting a target with oblique incidence in dynamic explosion. The vertical component of the velocity of the fragments hitting the target is measured by a low-cost broken target, and the incident angle of the fragments hitting the target at each point is measured by a high-speed camera, thereby realizing the low-cost measurement of the velocity of fragments hitting the target with oblique incidence at multiple points.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A system for measuring the velocity of fragments hitting a target with oblique incidence in dynamic explosion, characterized in that: it includes a projectile coordinate calculation module, a double-layer broken target assembly, a distributed time measurement module, a real-time dynamic positioning instrument, and a terminal data processing module;

[0006] The output end of the projectile coordinate calculation module is connected to the input end of the terminal data processing module, and is used to obtain the spatial coordinates of the projectile explosion point and send them to the terminal data processing module;

[0007] The output end of the double-layer broken target component is connected to the input end of the distributed timing module. Its target surface has a regular shape and is used to respond to the process of fragments penetrating the target during an explosion, and generate a first target-penetrating signal and a second target-penetrating signal and send them to the distributed timing module;

[0008] The output end of the distributed timing module is connected to the input end of the terminal data processing module, and is used to obtain the specific time points of the first target-penetrating signal and the second target-penetrating signal, and send them to the terminal data processing module;

[0009] The output end of the real-time dynamic locator is connected to the input end of the terminal data processing module, and is used to obtain at least three physical coordinates evenly distributed on the edge of the target surface of the double-layer broken target component, and send them to the terminal data processing module;

[0010] The terminal data processing module is used to calculate the fragment hitting target speed based on the obtained spatial coordinates of the projectile explosion point, the specific time points of the first target-penetrating signal and the second target-penetrating signal, and the three physical coordinates.

[0011] Further, the double-layer broken target component includes a first target paper, a first interlayer, a second target paper, a second interlayer, and a support plate that are sequentially stacked along the flying direction of the fragments;

[0012] The first target paper is densely arranged with first wires in a serpentine shape for obtaining the first target-penetrating signal;

[0013] The second target paper is densely arranged with second wires in a serpentine shape for obtaining the second target-penetrating signal;

[0014] The first wire and the second wire are respectively connected to the input end of the distributed timing module.

[0015] Further, both the first target paper and the second target paper are PCB target papers;

[0016] Both the first interlayer and the second interlayer are xps foam board interlayers;

[0017] Both the first wire and the second wire are copper wires;

[0018] The support plate is a wooden board.

[0019] Further, the distributed timing module includes a first constant current power supply module, a second constant current power supply module, a first conditioning and conversion unit, a second conditioning and conversion unit, a time acquisition unit, a data cache module, a broken target moment reading module, and a core control module;

[0020] The first constant current power supply module is connected to the first wire and is used to supply power to the first wire to make the first wire generate a first electrical signal; when the fragment penetrates the first target paper and cuts off the first wire, the first target-penetrating signal is generated in the first electrical signal;

[0021] The second constant current power supply module is connected to the second wire and is used to supply power to the second wire to generate a second electrical signal; when the fragment passes through the second target paper and cuts off the second wire, a second through-target signal is generated in the second electrical signal;

[0022] The input end of the first conditioning and conversion unit is connected to the first wire, and its output end is connected to the core control module. It is used to modulate the first electrical signal and convert it into a first digital signal and send it to the core control module, and send a first trigger signal corresponding to the first through-target signal to the core control module;

[0023] The input end of the second conditioning and conversion unit is connected to the second wire, and its output end is connected to the core control module. It is used to modulate the second electrical signal and convert it into a second digital signal and send it to the core control module, and send a second trigger signal corresponding to the second through-target signal to the core control module;

[0024] The time acquisition unit is connected to the core control module and is used to mark the time for the first digital signal and the second digital signal;

[0025] The data cache module is connected to the core control module and is used to cache the first digital signal and the second digital signal;

[0026] The through-target moment reading module is connected to the core control module and is used to respectively obtain the specific time points of the first through-target signal and the second through-target signal from the first digital signal and the second digital signal marked with time based on the first trigger signal and the second trigger signal, and send them to the terminal data processing module through the core control module;

[0027] The core control module is wirelessly connected to the terminal data processing module through the first wireless communication module.

[0028] Further, the first conditioning and conversion unit includes a first analog signal conditioning module, a first voltage comparator, and a first high-speed analog-to-digital conversion module;

[0029] The input end of the first analog signal conditioning module is connected to the first wire, and its output end is respectively connected to the input ends of the first voltage comparator and the first high-speed analog-to-digital conversion module. It is used to modulate the amplitude of the first electrical signal to amplify it, and then send it to the first voltage comparator and the first high-speed analog-to-digital conversion module respectively;

[0030] The output end of the first voltage comparator is connected to the core control module and is used to compare the first electrical signal with a preset threshold. When the first electrical signal is greater than the preset threshold, the first voltage comparator sends a first trigger signal to the core control module;

[0031] The output end of the first high-speed analog-to-digital conversion module is connected to the core control module, and is used to convert the modulated first electrical signal into a first digital signal and send it to the core control module.

[0032] Further, the second conditioning and conversion unit includes a second analog signal conditioning module, a second voltage comparator, and a second high-speed analog-to-digital conversion module;

[0033] The input end of the second analog signal conditioning module is connected to the second wire, and its output end is respectively connected to the input ends of the second voltage comparator and the second high-speed analog-to-digital conversion module, and is used to modulate the amplitude of the second electrical signal to amplify it, and then send it to the second voltage comparator and the second high-speed analog-to-digital conversion module respectively;

[0034] The output end of the second voltage comparator is connected to the core control module, and is used to compare the second electrical signal with a preset threshold value. When the second electrical signal is greater than the preset threshold value, the second voltage comparator sends a second trigger signal to the core control module;

[0035] The output end of the second high-speed analog-to-digital conversion module is connected to the core control module, and is used to convert the modulated second electrical signal into a second digital signal and send it to the core control module.

[0036] Further, the projectile coordinate calculation module includes a first high-speed camera, a second high-speed camera, and a pre-processing image computer;

[0037] The shooting ends of the first high-speed camera and the second high-speed camera face the preset position of the projectile explosion point and are connected to the input end of the pre-processing image computer, and are used to obtain the image data at the moment of the projectile explosion and send it to the pre-processing image computer;

[0038] The output end of the pre-processing image computer is connected to the terminal data processing module through the second wireless communication module, and is used to calculate the spatial coordinates of the projectile explosion point based on the binocular vision calculation method through the obtained image data and send it to the terminal data processing module.

[0039] Further, the terminal data processing module includes a third wireless communication module and a remote computer connected in sequence;

[0040] The third wireless communication module is wirelessly connected to the first wireless communication module and the second wireless communication module respectively;

[0041] The remote computer is connected to the real-time kinematic positioning instrument and is used to calculate the fragment hitting target speed.

[0042] Further, the time acquisition unit includes a GPS timing and timekeeping module and a GPS antenna connected to the GPS timing and timekeeping module;

[0043] The GPS timing module is connected to the core control module and is used to mark the GPS absolute time on the first digital signal and the second digital signal based on the GPS signal obtained by the GPS antenna.

[0044] Furthermore, it also includes a target breaking bracket;

[0045] The broken target bracket includes a base frame, a support frame and a bracket for mounting a double-layer broken target assembly;

[0046] The chassis is used to be supported on the ground;

[0047] One end of the support frame is rotatably connected to one end of the base frame, and a plurality of adjustment holes are provided on the support frame;

[0048] One end of the bracket is rotatably connected to the other end of the base frame, and the other end of the bracket is adjustably connected to the support frame through the adjustment hole, so as to adjust the angle between the double-layer broken target assembly and the base frame.

[0049] A method for measuring the impact velocity of kinetic explosion oblique-incidence fragments is provided, which uses the above-mentioned kinetic explosion oblique-incidence fragment impact velocity measurement system. The method is characterized in that it includes the following steps:

[0050] Step 1: At the moment of projectile explosion, the spatial coordinates of the projectile explosion point are obtained through the projectile coordinate solution module and sent to the terminal data processing module; the first target penetration signal and the second target penetration signal generated during the target penetration process of the explosion fragments are obtained through the double-layer target breaking assembly, and sent to the terminal data processing module; the specific time points of the first target penetration signal and the second target penetration signal are obtained through the distributed timing module and sent to the terminal data processing module; the physical coordinates of at least three points evenly distributed on the edge of the target surface of the double-layer target breaking assembly are obtained through the real-time dynamic locator and sent to the terminal data processing module;

[0051] Step 2: Calculate the impact velocity of fragments;

[0052] 2.1. Calculate the target surface normal vector and the physical coordinates of the target surface center point based on the physical coordinates of at least three points evenly distributed on the edge of the target surface. Calculate the flight vector of the fragment in the flight direction based on the spatial coordinates of the projectile explosion point and the physical coordinates of the target surface center point.

[0053] 2.2. Calculate the inner product of the flight vector and the target surface normal vector to obtain the cosine value of the incident angle of the fragments entering the double-layer broken target assembly;

[0054] 2.3. Calculate the vertical component of the fragment impact velocity based on the specific time points of the first and second target penetration signals;

[0055] 2.4. Calculate the ratio of the vertical component of the velocity to the cosine of the angle of incidence to obtain the impact velocity of the fragments.

[0056] Further, step 2.3 is specifically as follows:

[0057] 2.3.1. Calculate the time difference between the first and second target penetration signals based on their specific time points.

[0058] 2.3.2. Calculate the ratio of the first sandwich thickness to the time difference to obtain the vertical component of the fragment impact velocity.

[0059] Advantages of the present invention:

[0060] 1. The dynamic explosion oblique-incidence fragment impact velocity measurement system and method proposed by the present invention can measure the fragment velocity when the fragment obliquely impacts the target surface. Existing fragment velocity measurement devices such as double-light screen velocity measurement targets are only applicable to static explosion experiments where the fragment flight direction is perpendicular to the target surface and cannot measure the incident angle of the fragment when it impacts the target surface. The present invention measures the velocity component of the fragment perpendicular to the target surface through a double-layer broken target component, and uses a real-time kinematic (RTK) and a projectile coordinate calculation module to measure the fragment incident angle, realizing the measurement of the fragment impact velocity under oblique-incidence conditions.

[0061] 2. The dynamic explosion oblique-incidence fragment impact velocity measurement system and method proposed by the present invention can be deployed on a large scale in batches. Although the existing radar method can obtain fragment flight trajectory data in a local area, its cost is high and it is difficult to protect, and the number of measurement points deployed is greatly limited. The double-layer broken target component provided by the present invention is manufactured by PCB technology, with low manufacturing cost, and can realize the simultaneous deployment of dozens of measurement points in a single experiment, avoiding the measurement difficulties caused by the uncertain fragment trajectory, and can be applied to harsh environments.

[0062] 3. The dynamic explosion oblique-incidence fragment impact velocity measurement system and method proposed by the present invention have the characteristics of low deployment cost. For existing fragment velocity measurement devices, in order to supply power centrally and provide effective protection, it is necessary to dig cable trenches, lay cables, and build shelters, resulting in a large amount of construction work. The distributed timing module adopted by the present invention can directly measure the fragment target penetration time, and has the advantages of small volume, low power consumption, long offline working time, and wireless data transmission. It is directly deployed under the broken target and does not require cable pulling and shelter construction, with extremely low construction costs. Description of the Drawings

[0063] Figure 1 - Structural schematic diagram of an embodiment of a dynamic explosion oblique-incidence fragment impact velocity measurement system of the present invention;

[0064] Figure 2 - Structural schematic diagram of the broken target support in the embodiment of the present invention;

[0065] Figure 3 - Explosion diagram of the double-layer broken target component in the embodiment of the present invention;

[0066] Figure 4 、Layout diagram of the fragment impact velocity measurement system with oblique impact in the dynamic explosion embodiment of the present invention;

[0067] Figure 5 、Schematic diagram of the fragment incident angle calculation method in the embodiment of the present invention.

[0068] Reference numerals in the drawings:

[0069] 1 - Double - layer broken target assembly, 11 - First target paper, 12 - First interlayer, 13 - Second target paper, 14 - Second interlayer, 15 - Support plate, 16 - First wire, 17 - Second wire, 2 - Distributed timing module, 3 - First high - speed camera, 4 - Second high - speed camera, 5 - Pre - image - processing computer, 6 - Remote computer, 7 - Broken target support, 71 - Base frame, 72 - Support frame, 73 - Bracket, 74 - Adjusting hole. Detailed implementation manners

[0070] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0071] A fragment impact velocity measurement system with oblique impact in the dynamic explosion of this embodiment. The system measures the component of the fragment impact velocity perpendicular to the target surface through the double - layer broken target assembly, and uses the method of binocular vision of the real - time kinematic (RTK) and the projectile coordinate calculation module to measure the incident angle of the fragment when it impacts the target, solving the problem of low - cost measurement of the fragment impact velocity at multiple measurement points under dynamic explosion conditions.

[0072] Combined with Figure 1 and Figure 4 as shown, the fragment impact velocity measurement system includes a projectile coordinate calculation module, a double - layer broken target assembly 1, a distributed timing module 2, a real - time kinematic (RTK), a terminal data processing module, and a broken target support 7.

[0073] The output end of the projectile coordinate calculation module is connected to the input end of the terminal data processing module, and is used to obtain the spatial coordinates of the projectile explosion point and send them to the terminal data processing module; the projectile coordinate calculation module can calculate the spatial coordinates of the projectile explosion point.

[0074] Specifically, the projectile coordinate calculation module includes a first high-speed camera 3, a second high-speed camera 4, and a pre-processing computer 5 for images. The shooting ends of the first high-speed camera 3 and the second high-speed camera 4 face the preset position of the projectile explosion point and are connected to the input end of the pre-processing computer 5 for images, and are used to obtain the image data at the moment of the projectile explosion and send it to the pre-processing computer 5 for images. The output end of the pre-processing computer 5 for images is connected to the terminal data processing module through the second wireless communication module, and is used to calculate the spatial coordinates (initial coordinates) of the projectile explosion point based on the binocular vision calculation method through the obtained image data and send it to the terminal data processing module.

[0075] The output end of the double-layer broken target component 1 is connected to the input end of the distributed timing module 2. Its target surface is a regular shape, which is a square in this embodiment. The double-layer broken target component 1 is used to respond to the target-piercing process of the fragments generated by the explosion and generate a first target-piercing signal and a second target-piercing signal and send them to the distributed timing module 2.

[0076] Specifically, as Figure 3 shown, the double-layer broken target component 1 includes a first target paper 11, a first interlayer 12, a second target paper 13, a second interlayer 14, and a support plate 15 that are sequentially stacked along the flying direction of the fragments. On the first target paper 11, a first wire 16 for obtaining the first target-piercing signal is densely arranged in a serpentine shape by a printed circuit process. On the second target paper 13, a second wire 17 for obtaining the second target-piercing signal is densely arranged in a serpentine shape by a printed circuit process. The first wire 16 and the second wire 17 are respectively connected to the input end of the distributed timing module 2. Both the first target paper 11 and the second target paper 13 are PCB target papers; both the first interlayer 12 and the second interlayer 14 are xps foam board interlayers; both the first wire 16 and the second wire 17 are copper wires; the support plate 15 is a wooden board. When the fragments penetrate the first target paper 11 and the second target paper 13, the first wire 16 and the second wire 17 are cut off, and at the same time, a first target-piercing signal and a second target-piercing signal are generated. The first interlayer 12 separates the first target paper 11 and the second target paper 13 at a fixed distance, and the second interlayer 14 separates the first target paper 11 and the second target paper 13 from the wooden board at a fixed distance, so that the resistance characteristics of the fragments when passing through the first target paper 11 and the second target paper 13 are consistent.

[0077] The output end of the distributed timing module 2 is connected to the input end of the terminal data processing module, and is used to obtain the specific time points of the first target-piercing signal and the second target-piercing signal and send them to the terminal data processing module.

[0078] Specifically, the distributed timing module 2 is powered by a lithium battery. The distributed timing module 2 includes a first constant current power supply module, a second constant current power supply module, a first conditioning and conversion unit, a second conditioning and conversion unit, a time acquisition unit, a data cache module, a broken target moment reading module, and a core control module. The first constant current power supply module is connected to the first wire 16 through a small radio frequency circuit interface (SMA) and is used to supply power to the first wire 16 to generate a first electrical signal on the first wire 16. The second constant current power supply module is connected to the second wire 17 through a small radio frequency circuit interface (SMA) and is used to supply power to the second wire 17 to generate a second electrical signal on the second wire 17.

[0079] The input end of the first conditioning and conversion unit is connected to the first wire 16, and its output end is connected to the core control module. It is used to modulate the first electrical signal and convert it into a first digital signal and send it to the core control module, and send a first trigger signal corresponding to the first bullet-through signal to the core control module. The input end of the second conditioning and conversion unit is connected to the second wire 17, and its output end is connected to the core control module. It is used to modulate the second electrical signal and convert it into a second digital signal and send it to the core control module, and send a second trigger signal corresponding to the second bullet-through signal to the core control module. The time acquisition unit is connected to the core control module and is used to label time for the first digital signal and the second digital signal. The data cache module is connected to the core control module and is used to cache the first digital signal and the second digital signal. The broken target moment reading module is connected to the core control module and is used to respectively obtain the specific time points of the first bullet-through signal and the second bullet-through signal from the first digital signal and the second digital signal with labeled time based on the first trigger signal and the second trigger signal, and send them to the terminal data processing module through the core control module. The core control module is wirelessly connected to the terminal data processing module through the first wireless communication module and is used to coordinate the synchronous operation of each sub-module. The distributed timing module 2 has 2 SMA interface sampling channels and supports 3 trigger modes, including signal self-triggering, timing triggering, and manual triggering.

[0080] Among them, the first conditioning and conversion unit includes a first analog signal conditioning module, a first voltage comparator, and a first high-speed analog-to-digital conversion module (high-speed ADC); the input end of the first analog signal conditioning module is connected to the first wire 16 through a small radio frequency circuit interface (SMA), and its output end is respectively connected to the input ends of the first voltage comparator and the first high-speed analog-to-digital conversion module, and is used to modulate the amplitude of the first electrical signal to amplify it, and then send it to the first voltage comparator and the first high-speed analog-to-digital conversion module respectively; the output end of the first voltage comparator is connected to the core control module, and is used to compare the first electrical signal with a preset threshold. When the first electrical signal is greater than the preset threshold, the first voltage comparator sends a first trigger signal to the core control module; the output end of the first high-speed analog-to-digital conversion module is connected to the core control module, and is used to convert the modulated first electrical signal into a first digital signal and send it to the core control module.

[0081] The second conditioning and conversion unit includes a second analog signal conditioning module, a second voltage comparator, and a second high-speed analog-to-digital conversion module (high-speed ADC); the input end of the second analog signal conditioning module is connected to the second wire 17 through a small radio frequency circuit interface (SMA), and its output end is respectively connected to the input ends of the second voltage comparator and the second high-speed analog-to-digital conversion module, and is used to modulate the amplitude of the second electrical signal to amplify it, and then send it to the second voltage comparator and the second high-speed analog-to-digital conversion module respectively; the output end of the second voltage comparator is connected to the core control module, and is used to compare the second electrical signal with a preset threshold. When the second electrical signal is greater than the preset threshold, the second voltage comparator sends a second trigger signal to the core control module; the output end of the second high-speed analog-to-digital conversion module is connected to the core control module, and is used to convert the modulated second electrical signal into a second digital signal and send it to the core control module.

[0082] The time acquisition unit includes a GPS timing and holdover module and a GPS antenna connected to the GPS timing and holdover module; the GPS timing and holdover module is connected to the core control module, and is used to mark the GPS absolute time for the first digital signal and the second digital signal based on the GPS signal obtained by the GPS antenna.

[0083] The output end of the real-time kinematic positioning instrument is connected to the input end of the terminal data processing module, and is used to obtain the physical coordinates of the four corner points of the target surface edge of the double-layer broken target assembly 1 and send them to the terminal data processing module;

[0084] The terminal data processing module is used to calculate the fragment impact velocity based on the obtained spatial coordinates of the projectile explosion point, the specific time points of the first target penetration signal and the second target penetration signal, and the physical coordinates of the four corner points.

[0085] Specifically, the terminal data processing module includes a third wireless communication module and a remote computer 6 connected in sequence; the third wireless communication module is wirelessly connected to the first wireless communication module and the second wireless communication module respectively; the remote computer 6 is connected to the real-time kinematic (RTK) positioning device and is used to calculate the fragment impact velocity. The remote computer has a built-in impact velocity calculation method, which can calculate the impact velocity values of each double-layer target-breaking fragment based on the received data.

[0086] The target-breaking support 7 is used to support the double-layer target-breaking assembly 1 and can fix the double-layer target-breaking assembly 1 on the ground at a specified orientation and angle.

[0087] Specifically, as Figure 2 shown, the target-breaking support 7 includes a base frame 71, a support frame 72, and a bracket 73 for installing the double-layer target-breaking assembly 1; the base frame 71 is used to support on the ground and can provide overall support for the target-breaking support; one end of the support frame 72 is rotatably connected to one end of the base frame 71, and a plurality of adjustment holes 74 are provided on the support frame 72; the bracket 73 can fix and support the double-layer target-breaking assembly 1; one end of the bracket 73 is rotatably connected to the other end of the base frame 71, and the other end of the bracket 73 is adjustably connected to the support frame 72 through the adjustment holes 74 to adjust the angle between the double-layer target-breaking assembly 1 and the base frame 71.

[0088] When measuring using the fragment impact velocity measurement system of claim 1, combined with Figures 4 to 5 shown, it includes the following steps:

[0089] Step 1: At the moment of the projectile explosion, obtain the spatial coordinates of the projectile explosion point through the projectile coordinate resolution module and send them to the terminal data processing module; obtain the first target-penetrating signal and the second target-penetrating signal generated during the process of the fragments penetrating the target through the double-layer target-breaking assembly 1 and send them to the terminal data processing module; obtain the specific time points of the first target-penetrating signal and the second target-penetrating signal through the distributed timing module 2 and send them to the terminal data processing module; obtain the physical coordinates of the four corner points of the target surface of the double-layer target-breaking assembly through the real-time kinematic (RTK) positioning device and send them to the terminal data processing module; specifically:

[0090] 1.1. Arrange the double-layer target-breaking assembly 1 and the target-breaking support 7. The normal vector of the target surface of the double-layer target-breaking assembly 1 should point to the predetermined explosion center to reduce the probability of the fragment only passing through one layer of target paper. First, fix the double-layer target-breaking assembly 1 on the bracket 73 of the target-breaking support 7 with self-tapping screws, and then repeatedly adjust the angle between the bracket 73 and the base frame 71 until the normal vector of the target surface of the double-layer target-breaking assembly 1 approximately points to the predetermined explosion center.

[0091] 1.2. Deploy a distributed timing module, connect the first wire 16 and the second wire 17 to two timing SMA interfaces of the distributed timing module 2, and then connect the GPS antenna to the antenna interface of the distributed timing module 2. Start the distributed timing module 2 to detect the connection status of the line. After confirming that the first wire 16, the second wire 17, and the GPS antenna are connected, place the distributed timing module 2 into a dust-proof box and protect the dust-proof box with sandbags.

[0092] 1.3. Use RTK to measure the physical coordinates A(x A ,y A ,y A )、B(x B ,y B ,y B )、C(x C ,y C ,y C )、D(x D ,y D ,y D ) of the four corner points of the target surface of the double-layer broken target component 1. Take the average value of each component of the coordinates of the four corner points, which is the physical coordinate F(x F ,y F ,y F ) of the center point of the target surface;

[0093] 1.4. Deploy the first high-speed camera 3 and the second high-speed camera 4 in two directions orthogonal to the line connecting to the predetermined ground zero projection point, and complete the calibration work of the first high-speed camera 3 and the second high-speed camera 4. The first high-speed camera 3 and the second high-speed camera 4 can obtain the images of the projectile explosion. According to the binocular vision algorithm, the spatial coordinates of the projectile explosion point, that is, the initial coordinates O(x O ,y O ,y O ) of the fragments can be obtained.

[0094] 1.5. Two hours before the experiment, first turn on the power of the distributed timing module 2 and confirm whether the line connection and the GPS timing status are normal; then turn on the power of the projectile coordinate calculation module and confirm whether the image storage status of the projectile coordinate calculation module is normal. After the experiment starts, the projectile coordinate calculation module will store the images at the moment of the projectile explosion, and the distributed timing module 2 will record the broken target times t1 and t2 when the fragments pass through the first target paper 11 and the second target paper 13.

[0095] Step 2. Calculate the hitting speed of the fragments;

[0096] 2.1. Calculate the normal vector of the target surface and the physical coordinates of the center point of the target surface based on the physical coordinates of the four corner points of the target surface edge, and calculate the flight vector of the fragments in the flight direction based on the spatial coordinates of the projectile explosion point and the physical coordinates of the center point of the target surface;

[0097] Normalize the cross product of two vectors formed by taking three of the corner points to obtain the normalized normal vector of the target surface.

[0098]

[0099] 2.2. Calculate the inner product of the flight vector and the target surface normal vector to obtain the cosine value of the incident angle of the fragment on the double-layer broken target assembly.

[0100] Since the flight distance of the fragment is much greater than the size of the projectile and the broken target, it can be considered that the initial coordinates of the fragment are the spatial coordinates of the projectile explosion point, and the target hitting coordinates of the fragment are the physical coordinates of the center point of the target surface. Using the binocular vision algorithm and combining with the image of the projectile explosion moment obtained by the projectile coordinate calculation module, the spatial coordinates O(x O , y O , y O ) of the projectile explosion point can be obtained. Combining the spatial coordinates of the projectile explosion point and the physical coordinates of the center point of the target surface, the normalized vector of the fragment flight direction and the flight distance S can be obtained. Take the absolute value of the dot product of and , which is the cosine value cosθ of the angle between the fragment flight direction and the target surface normal direction.

[0101]

[0102]

[0103]

[0104] 2.3. Calculate the vertical component of the velocity of the fragment hitting the target based on the specific time points of the first target penetration signal and the second target penetration signal. Specifically:

[0105] 2.3.1. Calculate the time difference △ td = t2 - t1 between the first target penetration signal and the second target penetration signal based on their specific time points.

[0106] 2.3.2. Calculate the ratio of the thickness of the first interlayer 12 to the time difference to obtain the vertical component v ⊥ of the velocity of the fragment hitting the target. The component v ⊥ of the velocity of the fragment hitting the target perpendicular to the target surface is equal to the ratio of the distance d between the first target paper 11 and the second target paper 13 to the time difference △ td = t2 - t1 when the fragment passes through the first target paper 11 and the second target paper 13.

[0107]

[0108] 2.4. Calculate the ratio of the vertical component of the impact velocity to the cosine of the angle of incidence to obtain the impact velocity of the fragment on the target.

[0109] As Figure 5 shown, the impact velocity v 12 of the fragment on the target is equal to the ratio of the component v ⊥ of the impact velocity of the fragment perpendicular to the target surface to the cosine cosθ of the angle of incidence of the fragment.

[0110]

[0111] Since the sizes of the projectile and the target surface are much smaller than the flight distance of the fragment, the initial coordinates of the fragment are approximately the spatial coordinates of the explosion point of the projectile, and the impact coordinates of the fragment on the target are approximately the physical coordinates of the center point of the target surface. The impact velocity of the fragment can be obtained according to the calculation method of the impact velocity.

[0112] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A measurement system for the impact velocity of fragments with oblique impact in dynamic explosion, characterized in that: It includes a projectile coordinate calculation module, a double-layer target-breaking component (1), a distributed time measurement module (2), a real-time kinematic positioning instrument, and a terminal data processing module; The output end of the projectile coordinate calculation module is connected to the input end of the terminal data processing module, and is used to obtain the spatial coordinates of the projectile explosion point and send them to the terminal data processing module; The output end of the double-layer target-breaking component (1) is connected to the input end of the distributed time measurement module (2). Its target surface is in a regular shape and is used to respond to the target-piercing process of the fragments generated by the explosion, and generate a first target-piercing signal and a second target-piercing signal and send them to the distributed time measurement module (2); The output end of the distributed time measurement module (2) is connected to the input end of the terminal data processing module, and is used to obtain the specific time points of the first target-piercing signal and the second target-piercing signal, and send them to the terminal data processing module; The output end of the real-time kinematic positioning instrument is connected to the input end of the terminal data processing module, and is used to obtain at least three physical coordinates evenly distributed on the edge of the target surface of the double-layer target-breaking component (1), and send them to the terminal data processing module; The terminal data processing module is used to calculate the target-piercing speed of the fragments based on the obtained spatial coordinates of the projectile explosion point, the specific time points of the first target-piercing signal and the second target-piercing signal, and the three physical coordinates.

2. The fragment impact velocity measurement system for dynamic explosion with oblique incidence according to claim 1, characterized in that: The double-layer target-breaking component (1) includes a first target paper (11), a first interlayer (12), a second target paper (13), a second interlayer (14), and a support plate (15) that are sequentially stacked along the flying direction of the fragments; The first target paper (11) is densely arranged with a first wire (16) for obtaining the first target-piercing signal in a snake shape; The second target paper (13) is densely arranged with a second wire (17) for obtaining the second target-piercing signal in a snake shape; The first wire (16) and the second wire (17) are respectively connected to the input end of the distributed time measurement module (2).

3. The fragment impact velocity measurement system for dynamic explosion with oblique incidence according to claim 2, wherein: Both the first target paper (11) and the second target paper (13) are PCB target papers; Both the first interlayer (12) and the second interlayer (14) are xps foam board interlayers; Both the first wire (16) and the second wire (17) are copper wires; The support plate (15) is a wooden board.

4. The dynamic explosion oblique incidence fragment target-piercing speed measurement system according to claim 3, characterized in that: The distributed time measurement module (2) includes a first constant current power supply module, a second constant current power supply module, a first conditioning and conversion unit, a second conditioning and conversion unit, a time acquisition unit, a data cache module, a target-breaking moment reading module, and a core control module; The first constant current power supply module is connected to the first wire (16) and is used to supply power to the first wire (16) to make the first wire (16) generate a first electrical signal; when the fragment passes through the first target paper (11) and cuts off the first wire (16), the first target-piercing signal is generated in the first electrical signal; The second constant current power supply module is connected to the second wire (17) and is used to supply power to the second wire (17) to make the second wire (17) generate a second electrical signal; when the fragment passes through the second target paper (13) and cuts off the second wire (17), the second target-piercing signal is generated in the second electrical signal; The input end of the first conditioning and conversion unit is connected to the first wire (16), and its output end is connected to the core control module. It is used to modulate the first electrical signal, convert it into a first digital signal and send it to the core control module, and send a first trigger signal corresponding to the first through-target signal to the core control module; The input end of the second conditioning and conversion unit is connected to the second wire (17), and its output end is connected to the core control module. It is used to modulate the second electrical signal, convert it into a second digital signal and send it to the core control module, and send a second trigger signal corresponding to the second through-target signal to the core control module; The time acquisition unit is connected to the core control module and is used to mark the time for the first digital signal and the second digital signal; The data cache module is connected to the core control module and is used to cache the first digital signal and the second digital signal; The through-target moment reading module is connected to the core control module and is used to respectively obtain the specific time points of the first through-target signal and the second through-target signal from the first digital signal and the second digital signal marked with time based on the first trigger signal and the second trigger signal, and send them to the terminal data processing module through the core control module; The core control module is wirelessly connected to the terminal data processing module through the first wireless communication module.

5. The moving explosion oblique-incidence fragment hitting target speed measurement system according to claim 4, wherein: The first conditioning and conversion unit includes a first analog signal conditioning module, a first voltage comparator, and a first high-speed analog-to-digital conversion module; The input end of the first analog signal conditioning module is connected to the first wire (16), and its output end is respectively connected to the input ends of the first voltage comparator and the first high-speed analog-to-digital conversion module. It is used to modulate the amplitude of the first electrical signal to amplify it, and then send it to the first voltage comparator and the first high-speed analog-to-digital conversion module respectively; The output end of the first voltage comparator is connected to the core control module and is used to compare the first electrical signal with a preset threshold. When the first electrical signal is greater than the preset threshold, the first voltage comparator sends a first trigger signal to the core control module; The output end of the first high-speed analog-to-digital conversion module is connected to the core control module and is used to convert the modulated first electrical signal into a first digital signal and send it to the core control module.

6. The moving explosion oblique-incidence fragment hitting target speed measurement system according to claim 5, wherein: The second conditioning and conversion unit includes a second analog signal conditioning module, a second voltage comparator, and a second high-speed analog-to-digital conversion module; The input end of the second analog signal conditioning module is connected to the second wire (17), and its output end is respectively connected to the input ends of the second voltage comparator and the second high-speed analog-to-digital conversion module. It is used to modulate the amplitude of the second electrical signal to amplify it, and then send it to the second voltage comparator and the second high-speed analog-to-digital conversion module respectively; The output end of the second voltage comparator is connected to the core control module, and is used to compare the second electrical signal with a preset threshold value. When the second electrical signal is greater than the preset threshold value, the second voltage comparator sends a second trigger signal to the core control module; The output end of the second high-speed analog-to-digital conversion module is connected to the core control module, and is used to convert the modulated second electrical signal into a second digital signal and send it to the core control module.

7. The dynamic explosion oblique-incidence fragment hitting target speed measurement system according to claim 6, wherein: The projectile coordinate calculation module includes a first high-speed camera (3), a second high-speed camera (4) and a pre-processing image computer (5); The shooting ends of the first high-speed camera (3) and the second high-speed camera (4) face the preset projectile explosion point position and are connected to the input end of the pre-processing image computer (5), and are used to acquire image data at the moment of projectile explosion and send it to the pre-processing image computer (5); The output end of the pre-processing image computer (5) is connected to the terminal data processing module through a second wireless communication module, and is used to calculate the spatial coordinates of the projectile explosion point based on the binocular vision calculation method through the acquired image data and send it to the terminal data processing module.

8. The dynamic explosion oblique-incidence fragment hitting target speed measurement system according to claim 7, wherein: The terminal data processing module includes a third wireless communication module and a remote computer (6) connected in sequence; The third wireless communication module is wirelessly connected to the first wireless communication module and the second wireless communication module respectively; The remote computer (6) is connected to a real-time kinematic positioning instrument and is used to calculate the fragment hitting target speed.

9. The dynamic explosion oblique-incidence fragment hitting target speed measurement system according to claim 8, wherein: The time acquisition unit includes a GPS timing and holdover module and a GPS antenna connected to the GPS timing and holdover module; The GPS timing and holdover module is connected to the core control module, and is used to label the GPS absolute time for the first digital signal and the second digital signal based on the GPS signal acquired by the GPS antenna.

10. The dynamic explosion oblique-incidence fragment hitting target speed measurement system according to claim 9, wherein: It further includes a target-breaking bracket (7); The target-breaking bracket (7) includes a base frame (71), a support frame (72) and a bracket (73) for installing a double-layer target-breaking assembly (1); The base frame (71) is used to support on the ground; One end of the support frame (72) is rotatably connected to one end of the base frame (71), and a plurality of adjustment holes (74) are provided on the support frame (72); One end of the bracket (73) is rotatably connected to the other end of the base frame (71), and the other end of the bracket (73) is adjustably connected to the support frame (72) through the adjustment holes (74) so as to adjust the angle between the double-layer target-breaking assembly (1) and the base frame (71).

11. A method for measuring the hitting velocity of fragments with dynamic explosion and oblique incidence, using the system for measuring the hitting velocity of fragments with dynamic explosion and oblique incidence described in claim 1, characterized in that, It includes the following steps: Step 1: At the moment of the projectile explosion, obtain the spatial coordinates of the projectile explosion point through the projectile coordinate calculation module and send them to the terminal data processing module; obtain the first target penetration signal and the second target penetration signal generated during the process of the fragments penetrating the target through the double-layer target-breaking component (1) and send them to the terminal data processing module; obtain the specific time points of the first target penetration signal and the second target penetration signal through the distributed timing module (2) and send them to the terminal data processing module; obtain at least three physical coordinates evenly distributed on the edge of the target surface of the double-layer target-breaking component through the real-time kinematic positioning instrument and send them to the terminal data processing module; Step 2: Calculate the fragment impact velocity on the target; 2.1 Calculate the normal vector of the target surface and the physical coordinates of the center point of the target surface based on at least three physical coordinates evenly distributed on the edge of the target surface, and calculate the flight vector of the fragment in the flight direction based on the spatial coordinates of the projectile explosion point and the physical coordinates of the center point of the target surface; 2.2 Calculate the inner product of the flight vector and the normal vector of the target surface to obtain the cosine value of the incident angle of the fragment into the double-layer target-breaking component; 2.3 Calculate the vertical component of the velocity of the fragment impact velocity based on the specific time points of the first target penetration signal and the second target penetration signal; 2.4 Calculate the ratio of the vertical component of the velocity to the cosine of the incident angle to obtain the fragment impact velocity on the target.

12. The method for measuring the impact velocity of fragments with oblique impact in dynamic explosion according to claim 11, wherein Specifically, step 2.3 is as follows: 2.3.1 Calculate the time difference between the first target penetration signal and the second target penetration signal based on the specific time points of the first target penetration signal and the second target penetration signal; 2.3.2 Calculate the ratio of the thickness of the first layer (12) to the time difference to obtain the vertical component of the velocity of the fragment impact velocity.

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