Target plate for simultaneously measuring speed, position and number of fragments

Abstract

The invention belongs to the field of target plate structure testing, and particularly relates to a target plate capable of simultaneously measuring speed, position and quantity of fragments, the front and back surfaces of the target plate are printed with same circuit structures, the front and back surface structures of the target plate are that resistors with odd numbers are arranged in series along a comb back on one side, and resistors with even numbers are arranged in series along a comb back on the other side; and conductive metal wires which are arranged in a comb tooth shape are uniformly distributed between every two adjacent resistors with odd numbers and between every two adjacent resistors with even numbers. When fragments hit the front face of the target plate and break through the target plate, the specific position and number of the fragments on the target plate can be determined by detecting voltage changes at the two ends of the load resistors on the front face and the back face of the target plate, and the average speed of the fragments can be obtained by combining the distance from the blasting center to the target plate and the time difference from signal triggering to target hitting measured by the data acquisition device. According to the invention, the number of detection lines is obviously reduced, and the simultaneous striking positions of a plurality of fragments can be measured, so that the simultaneous measurement of the speed, number and position of the fragments becomes possible.

Description

Technical Field

[0001] The invention belongs to the field of target plate structure testing, in particular to a target plate for simultaneously measuring fragment velocity, position and quantity, and is mainly used for testing fragment parameters generated by ammunition explosion to solve the problem of measuring the velocity, position and quantity of ammunition fragments when they act on a target object. Background Art

[0002] Target plates are widely used in explosion, impact tests and other parameter measurements of high-speed moving objects, especially in the testing of high-speed objects such as fragments and projectiles. The accuracy of the target plate is crucial to the reliability of the test results. At present, there are a variety of target plate structures used to measure parameters such as the speed, position and number of fragments at home and abroad, including coil targets, light curtain targets, ultrasonic shock wave targets, etc. In patent CN201010595287.9, the fragments interrupt the conductive metal wires on the parallel target plates, resulting in a decrease in the voltage on the signal load resistor. The number of interrupted conductive metal wires and the time difference between the projectile or fragments passing through the two parallel target plates can be calculated, and then the average speed and number of fragments between the two targets can be calculated, but the position of the fragments cannot be determined. The target plate of patent CN201910659140.2 uses two copper-clad plates fixed at a distance of centimeters, and uses the longitude and latitude detection lines composed of the broken wire detection block on the top layer and the parallel alternating comb-shaped copper film lines on the middle layer and the bottom layer to determine the fragment breakdown position and calculate the fragment vector speed and number. However, the large number of signal detection lines in its system reduces the wiring reliability, and it is even more impossible to identify the number of multiple fragments acting on the same small block at the same time. Patent CN201811607773.0 proposes a method of obtaining the load resistance voltage division when the fragment hits the target through a parallel resistor on the comb-shaped target to identify the type of fragment hitting the target, but this method can only identify the number of wires interrupted by the fragment. After the experiment, the target plate is often damaged or lost, and the order in which the fragments hit the target plate affects the corresponding relationship of the fragment holes on the target plate. These factors have become obstacles to the identification of fragment types. Patent CN202121300946.1 measures the projectile speed through two coil targets, and uses the change in magnetic flux caused by the projectile passing through the coil to generate an induced electromotive force to form a zone interception signal, but it cannot measure the position and number of fragments. The light curtain target of patent CN201811549512.8 determines the target position and speed of the projectile through the laser module and receiving tube on the two zone interception targets, but it is easily affected by the explosion dust and strong light and cannot be used. The portable shock wave target reporting system of patent CN202211714033.3 locates the landing point of the warhead by measuring the detached shock wave of the supersonic flying projectile or the explosion wave formed by the heavyweight warhead touching the ground or exploding, but it will not be able to identify fragments under the conditions of the simultaneous existence of shock waves, fragment shock waves and multi-path reflections generated by the explosion, and cannot be used in the explosion field environment.

[0003] In summary, there are still many limitations in the existing literature research. Some target plate structures cannot measure the position of fragments. Some target plates have reduced wiring reliability due to the large number of system signal detection lines. Some target plates can only identify the number of conductive metal wires broken by fragments, making it difficult to obtain the precise position of the fragments. In addition, light curtain targets and portable shock wave targets have strict requirements on the use environment conditions. Therefore, based on the research foundation of the aforementioned literature, the present invention proposes a composite structure target plate for measuring the motion parameters of fragments, which has a simple structure and high recognition. Summary of the invention

[0004] In order to solve the problem that the existing fragment velocity measuring target cannot accurately locate and determine the number of fragments when passing through the target plate, the present invention proposes a target plate that can simultaneously measure the speed, position and number of fragments.

[0005] The present invention is implemented by adopting the following technical scheme: a target plate for simultaneously measuring the speed, position and number of fragments, the front and back sides of the target plate are printed with the same circuit structure, wherein the structure on the back side is rotated 90 degrees relative to the front side structure; the circuit structures on the front and back sides are that odd-numbered resistors are arranged in series along a comb back on one side, and even-numbered resistors are arranged in series along a comb back on the other side, and conductive metal wires arranged in a comb-tooth shape are evenly distributed between every two adjacent odd-numbered resistors and between every two adjacent even-numbered resistors; wherein the size of the odd-numbered resistors is R, and the size of the even-numbered resistors is M times that of the odd-numbered resistors; the comb back ends where the odd-numbered resistors are located are all connected to a power supply VCC, the comb back end where the even-numbered resistors on the front side of the target plate are located leads out a signal line connected to the ground through a front load resistor, and the comb back end where the even-numbered resistors on the back side of the target plate are located leads out a signal line connected to the ground through a back load resistor, and a data acquisition device acquires the voltages of the front load resistor and the back load resistor.

[0006] The above-mentioned target plate for simultaneously measuring the speed, position and number of fragments, the measuring method of the target plate is:

[0007] When the fragments hit the front of the target plate, part of the conductive metal wire on the target surface is turned on. Due to the different number of fragments and the positions hitting the target surface, the equivalent resistance value in series with the front load resistor is different. The voltage signal on the front load resistor collected by the data acquisition device will change accordingly. The horizontal position of the fragments and the number of the fragments hitting the target surface can be calculated from the voltage division of the front load resistor.

[0008] When the fragments pass through the target plate, part of the conductive metal wire on the reverse side is turned on. Since the number of fragments and the positions hitting the target surface are different, the equivalent resistance value in series with the reverse load resistor is different. The voltage signal on the reverse load resistor collected by the data acquisition device will change accordingly. The vertical position of the fragments and the number of hits on the target surface can be calculated from the voltage division of the reverse load resistor.

[0009] The combination of the fragments in two directions can determine the exact position where the fragments hit the target surface.

[0010] In the target plate for simultaneously measuring the speed, position and number of fragments, the distance X0 from the explosion center to the target plate is known. When the data acquisition device detects a trigger signal, it starts to start the counter to count. The clock period of the counter is fixed. When it detects the voltage division on the front load resistor, the counter ends counting. The count value is multiplied by the period of the counting clock to obtain the time for the fragments to travel from the explosion center to the target plate. The average speed of the fragments is obtained by the time and the distance X0 from the explosion center to the target plate.

[0011] In the target plate for simultaneously measuring the speed, position and quantity of fragments, the conductive metal wire has a width of 1 to 6 mm and a conductive metal wire spacing of 1 to 6 mm.

[0012] Compared with traditional longitude and latitude targets, the target plate of the present invention significantly reduces the number of detection lines and can measure the simultaneous impact positions of multiple fragments, making it possible to simultaneously measure the speed, number and position of fragments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an application principle diagram of the target plate for measuring fragment velocity, position and quantity according to the present invention.

[0014] Figure 2 It is a front schematic diagram of the target plate of the present invention.

[0015] Figure 3 This is a front schematic diagram of the fragments of the present invention hitting the target plate.

[0016] In the figure: 1-target board, 2-front signal line, 3-rear signal line, 4-power supply VCC, 5-data acquisition device, 6-fragment flight trajectory, 7-fragment, 8-target board bracket, 9-odd-numbered resistors connected in series in the circuit, 10-distance d between two conductive metal wires of the target board L , 11-front load resistance, 12-target fragment 1, 13-target fragment 2. DETAILED DESCRIPTION

[0017] Figure 1 The schematic diagram of the target plate for simultaneously measuring the speed, position and number of fragments of the present invention is shown in FIG. When the fragment 7 hits and passes through the target plate 1, the position and number of the fragments can be obtained according to the voltage signal of the load resistor collected by the data acquisition device 5, and the average speed of the fragments can be obtained according to the distance from the explosion center to the target plate 1 and the time difference from the signal triggering to the target impact measured by the data acquisition device 5.

[0018] Figure 2The front schematic diagram of the target board of the present invention. The same circuit structure is printed on both sides, and the structure on the back is rotated 90° relative to the front structure. The structure of the front and back of the target board is that the odd-numbered resistors are arranged in series along the back of one side, and the even-numbered resistors are arranged in series along the back of the other side. Between every two adjacent odd-numbered resistors and between every two adjacent even-numbered resistors, there are conductive metal wires arranged in a comb-like shape. The size of the odd-numbered resistors is R, that is, R1, R3, R5, ..., R 2N-1 =R, and the even-numbered resistors are M times the size of the odd-numbered resistors, i.e. R2, R4, R6, ..., R 2N =MR. The width of the conductive metal wire is 1 to 6 mm, and the distance between the conductive metal wires is 1 to 6 mm. The comb back ends where the odd-numbered resistors are located are all connected to the power supply VCC, the comb back ends where the even-numbered resistors on the front side of the target board are located are connected to the ground through a front load resistor R, and the comb back ends where the even-numbered resistors on the back side of the target board are located are connected to the ground through a back load resistor R, and the data acquisition device 5 collects the voltages of the front load resistor R and the back load resistor R.

[0019] When the fragment 7 hits the front of the target plate 1, part of the conductive metal wire on the target surface 1 is turned on. Since the number of fragments 7 and the positions hitting the target surface are different, the equivalent resistance value in series with the load resistor is different, and the voltage signal on the front load resistor collected by the data acquisition device 5 will change accordingly. The horizontal (X-axis) position of the fragment and the number of target surfaces hit can be calculated from the voltage division of the front load resistor 11; when the fragment 7 passes through the target plate, part of the conductive metal wire on the back side is turned on. Similarly, the vertical (Y-axis) position of the fragment can be calculated. The combination of the two directional positions can determine the precise position where the fragment hits the target surface.

[0020] The resistors on the target board of the present invention are numbered from right to left, and different conduction combinations will produce different equivalent resistances. Since the conduction of the conductive metal wire is directly related to the position and number of fragments hitting, and the series-parallel relationship of the resistors is determined at this time, the equivalent resistance corresponding to each hitting situation is unique. The voltage V on the front load resistor 11 is measured by the data acquisition device 5 O According to the front load resistance 11 and the equivalent resistance voltage division, the equivalent resistance R can be inferred. eq According to the uniqueness of the equivalent resistance in different conduction conditions, the equivalent resistance R eqThe series and parallel connection of the resistors at the conductive part of the target plate can be determined at this time, so as to determine the number and number of the conductive resistors, and combine the width and spacing of the conductive wires of the target plate to calculate the position of the fragment 7 in the horizontal (X-axis) direction. When the fragment 7 passes through the target plate 1, part of the conductive wires on the back of the target plate 1 are conductive, and the principle is the same as above. The position of the fragment 7 in the vertical (Y-axis) direction can be calculated by the conductive condition of the conductive wires on the back. Combining the position information in the horizontal (X-axis) and vertical (Y-axis) directions, the precise position where the fragment hits the target surface can be determined.

[0021] The following is an explanation of the situation where a single fragment and two fragments hit the target plate.

[0022] When a single fragment 7 hits the target plate 1, the equivalent circuit diagram, equivalent resistance and load resistance voltage division of the front side of the target plate 1 are shown in Table 1.

[0023] Table 1 Single fragment hitting the front of the target plate

[0024]

[0025]

[0026] When two fragments hit the two conductive metal wires on the front of the target plate at the same time, the equivalent circuit diagram, equivalent resistance and load resistance voltage division are shown in Table 2. The same is true for multiple fragments.

[0027] Table 2: Two fragments hitting the front of the target plate

[0028]

[0029] From Table 1, we can know the position of the fragment in the X-axis direction when it hits the target plate. Combined with the back of the target plate with a cross structure on the front side, we can get the position of the fragment in the Y-axis direction, and finally determine the exact position of the fragment. Combined with Table 1 and Table 2, we can infer that when multiple fragments hit the target plate, multiple conductive metal wires are connected, and then the position and number of the corresponding fragments can be obtained.

[0030] The distance X0 from the explosion center to the target plate is known. When the high-speed data acquisition device detects a trigger signal, the counter starts counting. The clock period of the counter is fixed. When it detects the voltage divider on the front load resistor, the counter ends counting. The count value is multiplied by the period of the counting clock to obtain the time for the fragments to travel from the explosion center to the target plate. The average speed of the fragments is obtained by this time and the distance X0 from the explosion center to the target plate.

[0031] The target plate can measure the fragment velocity, position and number of fragments in the target area.

Claims

1. A target plate for simultaneously measuring fragment velocity, position and quantity, characterized in that: The target plate (1) has the same circuit structure printed on both sides, wherein the structure on the back side is rotated 90 degrees relative to the structure on the front side; the circuit structure on both sides is that odd-numbered resistors are arranged in series along the back of one side, and even-numbered resistors are arranged in series along the back of the other side, and between every two adjacent odd-numbered resistors and between every two adjacent even-numbered resistors, conductive metal wires arranged in a comb-tooth shape are evenly distributed; wherein the size of the odd-numbered resistors is R, and the size of the even-numbered resistors is R / R of the odd-numbered resistors. M times; the comb back ends where the odd-numbered resistors are located are all connected to the power supply VCC, the comb back ends where the even-numbered resistors on the front side of the target board are located are connected to the ground through a front load resistor, and the comb back ends where the even-numbered resistors on the back side of the target board are located are connected to the ground through a back load resistor, and the data acquisition device (5) acquires the voltages of the front load resistor and the back load resistor.

2. A target plate for simultaneously measuring fragment velocity, position and quantity according to claim 1, characterized in that: The measurement method of the target plate is: When the fragments (7) hit the front side of the target plate (1), part of the conductive metal wire on the target surface is turned on. Since the number of fragments (7) and the positions of the fragments (7) hitting the target surface are different, the equivalent resistance value in series with the front load resistor is different, and the voltage signal on the front load resistor collected by the data acquisition device (5) will change accordingly. The horizontal position of the fragments and the number of fragments hitting the target surface can be calculated from the voltage division of the front load resistor. When the fragments (7) pass through the target plate (1), part of the conductive metal wire on the reverse side is turned on. Since the number of fragments (7) and the positions of the fragments hitting the target surface are different, the equivalent resistance value in series with the reverse load resistor is different, and the voltage signal on the reverse load resistor collected by the data acquisition device (5) will change accordingly. The vertical position of the fragments and the number of fragments hitting the target surface can be calculated from the voltage division of the reverse load resistor. The positions of the fragments (7) in two directions can be combined to determine the precise position where the fragments hit the target surface.

3. A target plate for simultaneously measuring fragment velocity, position and quantity according to claim 1 or 2, characterized in that: The distance from the explosion center to the target plate is known. X 0, the data acquisition device (5) detects the trigger signal and starts to start the counter to count. The clock cycle of the counter is fixed. When it detects the voltage division on the front load resistor, the counter ends counting. The count value is multiplied by the counting clock cycle to obtain the time from the explosion center to the target plate. The time and the distance from the explosion center to the target plate are obtained. X 0 gets the average fragment velocity.

4. A target plate for simultaneously measuring fragment velocity, position and quantity according to claim 3, characterized in that: The width of the conductive metal wire is 1 to 6 mm, and the distance between the conductive metal wires is 1 to 6 mm.

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