A large-area supersonic non-explosive bomb drop point measurement method

Abstract

The present application belongs to the field of exterior ballistic parameter testing, and particularly relates to a large-area supersonic non-explosive bomb drop point measurement method. A pair of linear laser emitters and photoelectric detectors are arranged at equal intervals and perpendicular to each other to form a grid-shaped detection field. A data acquisition device is used to collect and record the shock wave signals after the projectile passes through the detection field. The first triggering time of the shock wave and the subsequent three triggering times are recorded in sequence. The interval between the multiple triggering times in the X and Y directions and the linear photoacoustic detector is used to calculate the apparent velocity component of the shock wave in the plane of the drop point measurement area. The first triggering time in the X and Y directions is calculated, and the drop point position of the projectile can be calculated. The present application realizes accurate measurement of the drop point in a large-area range. The uncertainty problem caused by the triggering signal is avoided, ensuring the correct calculation of the apparent velocity component of the shock wave. The drop point position measurement under any incident angle can be completed, and there is no requirement for the caliber of the measured projectile.

Description

Technical Field

[0001] This invention belongs to the field of external ballistic parameter testing, specifically relating to a method for measuring the impact point of a large-area supersonic non-explosive projectile. Background Technology

[0002] The impact point of a projectile is a key parameter in assessing the ballistic damage effectiveness of a weapon at its final stage and is an important part of the testing and finalization process of weaponry. The impact point of non-explosive projectiles is obscured by large amounts of smoke and dust, making it difficult for existing impact point measurement equipment to accurately detect the impact point of non-explosive projectiles that are covered by smoke and dust.

[0003] Currently, infrared measurement technology is unaffected by weather conditions, but the short time between impact points and explosions places high demands on the frame rate of infrared cameras. Visible light measurement technology is similar to human eye observation; while it offers good accuracy and timeliness, it is significantly affected by visibility, making all-weather measurement impossible. Furthermore, the complex environment of a large field of view means that detecting the impact points of multiple projectiles can easily lead to mutual obstruction and target confusion. Acoustic wave measurement technology has a long detection range and is unaffected by visibility and field-of-view obstruction, allowing for all-weather use. However, it is easily affected by terrain, and for multiple projectiles with varying impact points in the spatiotemporal distribution, acoustic signals can easily become entangled, resulting in large impact point detection errors and low accuracy. Seismic wave measurement technology is affected by geological factors within the measurement area. The propagation medium is often non-uniform, and seismic wave propagation is complex, with both transverse and longitudinal waves present, making it difficult to distinguish the propagation mode.

[0004] Patent "ZL202310065193.8" employs a sparsely placed laser emitting array and a photodetector receiving array to form a measurement sensor, capable of measuring the coordinate position of a projectile within a single detection surface. While this method can obtain the projectile's coordinates, it suffers from the following problems: the detection frame limits the measurement field of view, making it impossible to construct a detection field of view larger than 100m × 100m; secondly, it cannot determine from which side the shock wave triggers the sensor, increasing the difficulty of calculating the shock wave's propagation velocity within the detection plane. Summary of the Invention

[0005] This invention provides a method for measuring the impact point of a large-area supersonic non-explosive bomb, which solves the problems of existing measurement methods having a small detection area that cannot be expanded to a large detection area, and having a complex calculation of the first trigger time due to the lack of judgment on the order of shock wave triggering the linear photoacoustic detector, which is prone to errors.

[0006] To achieve the above objectives, the technical solution adopted in this invention is a method for measuring the impact point of a large-area supersonic non-explosive bomb, comprising the following steps:

[0007] Step 1: Divide several linear laser emitters into two groups and evenly distribute them on the two sides of a designated rectangular area. Divide several photodetectors into two groups and correspondingly set them on the two opposite sides of the designated rectangular area. Adjust the linear laser emitters and photodetectors to be on the same plane, adjust the laser beam paths of the two groups of linear laser emitters to be orthogonal, and adjust the positions of the photodetectors for alignment. The linear laser emitters and photodetectors are paired to form a linear photoacoustic detector. After the projectile is launched and falls into the impact measurement area, the shock wave signal is collected.

[0008] Step 2: Determine the triggering order of the linear photoacoustic detectors based on the arrival time sequence of the shock waves recorded by the first two linear photoacoustic detectors triggered in the X and Y directions.

[0009] Step 3: Calculate the apparent velocity component v of the shock wave propagating in the plane of the impact point measurement. x+ v x- v y+ v y- ;

[0010] Step 4: Calculate the initial trigger time Δt0 in the X and Y directions respectively;

[0011] Step 5: Calculate the coordinates (x, y) of the landing point.

[0012] Furthermore, in step two above, if the two linear photoacoustic detectors do not trigger simultaneously, the method below is used to determine whether the triggering is sequential or reverse:

[0013] If the first linear photoacoustic detector triggered by the shock wave is numbered i (2≤i≤M-1), the three nearest linear photoacoustic detectors on its left and right sides are numbered i+1, i-1, and i+2 respectively, and the order of the two first triggered linear photoacoustic detectors is i and i+1, this is called sequential triggering.

[0014] If the first linear photoacoustic detector triggered by the shock wave is numbered i (3≤i≤M-1), the three nearest linear photoacoustic detectors on its left and right sides are numbered i-1, i-2, and i+1 respectively, and the order of the two first triggered linear photoacoustic detectors is i and i-1, this is called reverse triggering.

[0015] Furthermore, in step three above, when triggered sequentially, the X-axis calculation formula is as follows:

[0016]

[0017] Where S is the distance between the two linear photoacoustic detectors, and t is... i-1 t i t i+1 t i+2 These are the trigger times corresponding to the four linear photoacoustic detectors;

[0018] In step four, the initial trigger time Δt0 in the X direction is:

[0019]

[0020] The same applies to the Y direction.

[0021] Furthermore, in step three above, when triggered in reverse order, the X-direction calculation formula is as follows:

[0022]

[0023] Among them, t i-2 t i-1 t i t i+1 These are the trigger times corresponding to the four linear photoacoustic detectors;

[0024] In step four, the initial trigger time Δt0 in the X direction is:

[0025]

[0026] The same applies to the Y direction.

[0027] Furthermore, in step two above, when two linear photoacoustic detectors are triggered simultaneously, it is necessary to strengthen the judgment of the triggering mode of the other two linear photoacoustic detectors outside the two linear photoacoustic detectors, which can be determined as simultaneous triggering, sequential triggering under simultaneous triggering, or reverse triggering under simultaneous triggering.

[0028] Furthermore, in step three above, based on the two linear photoacoustic detectors i 左 i 右 and the two linear photoacoustic detectors i 左 -1、i 右 +1 trigger time t i左 t i右 t i左-1 t i右+1 The formula for calculating the X-axis is:

[0029]

[0030] The formula for calculating the Y-axis is similar.

[0031] Furthermore, in step four above, when triggered simultaneously, the formula for calculating the first trigger time Δt0 in the X direction is:

[0032]

[0033] Furthermore, in step four above, when triggering sequentially under simultaneous triggering, the formula for calculating the first triggering time Δt0 in the X direction is as follows:

[0034]

[0035] Furthermore, in step four above, during the reverse-order triggering under simultaneous triggering, the formula for calculating the first triggering time Δt0 in the X direction is as follows:

[0036]

[0037] Furthermore, the coordinates (x, y) of the landing point are obtained using the following formula.

[0038]

[0039] Compared with the prior art, the advantages of the present invention are as follows:

[0040] (1) Within the measurement area, this invention can be expanded to a larger detection target surface by using the same type of sensor in a modular splicing manner, according to measurement requirements. Depending on the actual situation, if the intensity of the projectile shock wave is high, the spacing of the linear photoacoustic detectors will be sparse; if the intensity of the projectile shock wave is low, the spacing of the linear photoacoustic detectors will be dense. It has strong compatibility with the measurement object and does not require changing the sensing equipment during measurement.

[0041] (2) Since the impact point of the projectile is random, the measurement method provided by the present invention first needs to determine the triggering order of the four linear photoacoustic detectors that are first triggered by the shock wave, so as to ensure that the apparent velocity component of the shock wave is calculated correctly; at the same time, the measurement method does not require a trigger signal, thus avoiding the uncertainty problem caused by the trigger signal.

[0042] (3) The present invention can calculate the apparent velocity components of the shock wave in four directions in the plane of impact point measurement, without being affected by the incident angle of the projectile, and can complete the measurement of the impact point position under any incident angle, while having no requirements on the caliber of the projectile being measured. Attached Figure Description

[0043] Figure 1 This is a schematic diagram illustrating the principle of the measurement method of the present invention;

[0044] Figure 2 This is a schematic diagram of a linear laser emitter and a photodetector.

[0045] Figure 3 This is a diagram illustrating sequential triggering.

[0046] Figure 4 This is a diagram illustrating reverse triggering.

[0047] Figure 5 This is a diagram illustrating simultaneous triggering;

[0048] Figure 6 This is a diagram illustrating sequential triggering under simultaneous triggering conditions;

[0049] Figure 7This is a diagram illustrating the reverse triggering process under simultaneous triggering;

[0050] The diagram labels are explained below:

[0051] 1-Linear laser emitter, 2-Photodetector, 3-Linear photoacoustic detector, 4-Aiming component. Detailed Implementation

[0052] To more clearly illustrate the technology of this invention, a more comprehensive description of the invention will be given below with reference to the accompanying drawings. The drawings show suitable embodiments of the invention. However, the invention can be implemented in various forms and is not limited to the embodiments described herein. The purpose of providing specific embodiments is to better understand the technical content of this invention.

[0053] The basic idea of ​​the measurement method provided by this invention is as follows: several pairs of linear laser emitters 1 and photodetectors 2 are arranged at equal intervals and orthogonally to form a grid-like detection field of view. The shock wave signal after the projectile passes through the detection field of view is collected and recorded by a data acquisition device. The moment when the shock wave first triggers the linear photoacoustic detector 3 and the subsequent three trigger moments are recorded in sequence. By using the interval between the multiple trigger moments in the X and Y directions and the linear photoacoustic detector 3, the apparent velocity component of the shock wave in the plane of the impact point measurement area is calculated, and the first trigger moment in the X and Y directions is calculated, so that the impact point position of the projectile can be calculated.

[0054] This invention provides a method for measuring the impact point of a large-area supersonic non-explosive bomb, comprising the following steps:

[0055] Step 1: Divide several linear laser emitters 1 into two groups and evenly distribute them on the two sides of a designated rectangular area. Divide several photodetectors 2 into two groups and correspondingly set them on the two opposite sides of the designated rectangular area. Adjust the linear laser emitters 1 and photodetectors 2 to be on the same plane. Adjust the laser beam paths of the two groups of linear laser emitters 1 to be orthogonal to each other. Adjust the position of the photodetectors 2 for alignment. Linear laser emitters 1 and photodetectors 2 are paired to form linear photoacoustic detectors 3. After the projectile is launched and falls to the impact measurement area, collect the shock wave signal.

[0056] See Figure 1In this embodiment, 28 linear laser emitters 1 are divided into two groups, each spaced 10m apart, and evenly distributed on the two sides of a designated rectangular area. 28 photodetectors 2 are also divided into two groups, correspondingly positioned on opposite sides of the designated rectangular area. The linear laser emitters 1 and photodetectors 2 are paired. A grid-like detection area is formed by modular splicing. With the origin of the impact point measurement coordinates as O, the laser path of the second-highest X-direction linear photoacoustic detector 3 in the diagram is designated as the x-axis, and the laser path of the second-leftmost Y-direction linear photoacoustic detector 3 is designated as the y-axis. The effective target area of ​​the predetermined impact point measurement region is a rectangular area of ​​100m × 100m. Regions ABCD in the diagram represent the areas orthogonally formed by six linear photoacoustic detectors 3 in each of the X and Y directions, where the shock wave is first triggered.

[0057] See Figure 2 A linear laser emitter 1 serves as the transmitter, and a photodetector 2 serves as the receiver. Both are mounted on a bracket with marked and coded positions, 3 meters above the ground. The linear laser emitter 1 uses a semiconductor laser with a wavelength of 1550nm. It has an aiming device 4 on top, the front panel with the linear laser emitter 1, and a three-dimensional adjustment base at the bottom. The photodetector 2 is a PIN photodetector 2 that conforms to the 1550nm wavelength of the semiconductor laser. It has a receiving aperture for aiming on the front panel and a three-dimensional adjustment base at the bottom.

[0058] Step two: Based on the arrival time sequence of the shock waves recorded by the two earliest triggered linear photoacoustic detectors 3 in the X and Y directions, determine the triggering sequence of the longitudinal linear photoacoustic detectors 3. Two scenarios are possible:

[0059] (i) The two linear photoacoustic detectors 3 are not triggered at the same time. The triggering methods are classified as follows;

[0060] Step 2-1-1, see Figure 3 If the first linear photoacoustic detector 3 triggered by the shock wave is numbered i (2≤i≤M-1), the numbers of the three nearest linear photoacoustic detectors 3 on its left and right sides are i+1, i-1, and i+2 respectively, and the order of the two linear photoacoustic detectors 3 that are triggered first is i and i+1, this is called sequential triggering.

[0061] Step 2-1-2, see Figure 4 If the sequence number of the first linear photoacoustic detector 3 triggered by the X-direction shock wave is i (3≤i≤M-1), the sequence numbers of the three nearest linear photoacoustic detectors 3 on its left and right sides are i-1, i-2, and i+1 respectively, and the order of the two linear photoacoustic detectors 3 that are triggered first is i and i-1, this is called reverse triggering.

[0062] (ii) When two linear photoacoustic detectors 3 are triggered simultaneously, it is necessary to strengthen the judgment of the triggering mode of the other two linear photoacoustic detectors 3 outside the two linear photoacoustic detectors 3, and classify the triggering mode as follows.

[0063] 1. See Figure 5 Two linear photoacoustic detectors 3i 左 with i 右 At the same time as the triggering, the i of the linear photoacoustic detectors 3 on both the left and right sides 左 -1 and i 右 +1 was then triggered simultaneously;

[0064] 2. See Figure 6 Two linear photoacoustic detectors 3i 左 with i 右 Simultaneously with the triggering, the i of the linear photoacoustic detector 3 左 -1 precedes i 右 +1 triggers sequentially when multiple events are triggered simultaneously.

[0065] 3. See Figure 7 The two linear photoacoustic detectors 3i 左 with i 右 Simultaneously with the triggering, the i of the linear photoacoustic detector 3 右 +1 precedes i 左 -1 triggers the reverse order of simultaneous triggers;

[0066] The same applies to the Y direction.

[0067] It should be noted that the waveform of the shock wave triggered linear photoacoustic detector 3 is significantly different from that of the projectile triggered linear photoacoustic detector 3. Please pay attention to the distinction.

[0068] Step 3: Calculate the apparent velocity component v of the shock wave propagating in the plane of the impact point measurement. x+ v x- v y+ v y- :

[0069] Based on the two scenarios given in step two, the calculations need to be treated differently. This embodiment only provides the calculation formula for the X-axis; the Y-axis calculation is similar.

[0070] (a) The two linear photoacoustic detectors 3 are not triggered simultaneously:

[0071] If it is sequentially triggered, the calculation formula is as follows:

[0072]

[0073] Where S is the distance between the two linear photoacoustic detectors;

[0074] If it is triggered in reverse order, the calculation formula is:

[0075]

[0076] (ii) When two linear photoacoustic detectors 3 are triggered simultaneously, based on the i of the two linear photoacoustic detectors 3 左 i 右 and the i of the two linear photoacoustic detectors 3 左 -1、i 右 +1 trigger time t i左 t i右 t i左-1 t i右+1 The calculation formula is:

[0077]

[0078] v in the positive and negative directions of the y-axis y+ v y- The calculation process is similar.

[0079] Step 4: Calculate the initial trigger times Δt0 and Δt0′ in the X and Y directions:

[0080] Based on the two scenarios given in step two, the calculations need to be treated differently. This embodiment only provides the calculation formula for the X-axis; the Y-axis calculation is similar.

[0081] (a) The two linear photoacoustic detectors 3 are not triggered simultaneously:

[0082] If it is sequentially triggered, the calculation formula is as follows:

[0083]

[0084] If it is triggered in reverse order, the calculation formula is:

[0085]

[0086] (II) Two linear photoacoustic detectors 3(i 左 with i 右 Simultaneously triggered:

[0087] 1. Two linear photoacoustic detectors 3(i 左 with i 右 ) Linear photoacoustic detectors 3 (i) on both sides 左 -1、i 右 +1) This is also triggered simultaneously, and the calculation formula is:

[0088]

[0089] 2. Two linear photoacoustic detectors 3(i 左 with i 右 The right-side linear photoacoustic detector 3 (i)右 +1) Triggered first, indicating sequential triggering; the calculation formula is as follows:

[0090]

[0091] 3. Two linear photoacoustic detectors 3(i 左 with i 右 The left side of the linear photoacoustic detector 3 (i) 左 -1) Triggered first, it is a reverse trigger, the calculation formula is:

[0092]

[0093] The calculation process for the first trigger time Δt0′ in the Y direction is similar.

[0094] Step 5: Calculate the landing point coordinates (x, y):

[0095]

[0096] The above-described embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited thereto. Any simple changes or equivalent substitutions of the technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for measuring the impact point of a large-area supersonic non-explosive bomb, characterized in that: Includes the following steps: Step 1: Divide several linear laser emitters (1) into two groups and distribute them evenly on the two sides of the set rectangular area. Divide several photodetectors (2) into two groups and set them on the opposite sides of the set rectangular area. Adjust the linear laser emitters (1) and photodetectors (2) to be on the same plane. Adjust the laser paths of the two groups of linear laser emitters (1) to be orthogonal to each other. Adjust the position of the photodetectors (2) for alignment. Linear laser emitters (1) and photodetectors (2) are paired to form a linear photoacoustic detector (3). After the projectile is launched and falls to the impact point measurement area, collect the shock wave signal. Step 2: Determine the triggering order of the linear photoacoustic detectors (3) based on the order of shock wave arrival times recorded by the two first-triggered linear photoacoustic detectors (3) in the X and Y directions. Step 3: Calculate the apparent velocity component of the shock wave propagating in the plane of the impact point measurement. , , , ; Step 4: Calculate the first trigger time in the X and Y directions based on the apparent velocity components, trigger sequence, and trigger time. and ; Step 5: Based on the initial trigger time, the velocity component, the trigger sequence, and the distance S between the two linear photoacoustic detectors (3), calculate the landing point coordinates (x, y).

2. The method for measuring the impact point of a large-area supersonic non-explosive bomb according to claim 1, characterized in that: In step two, if the two linear photoacoustic detectors (3) are not triggered simultaneously, the method below is used to determine whether the triggering is sequential or reverse: If the first linear photoacoustic detector (3) triggered by the shock wave is numbered i, 2≤i≤M-1, and the numbers of the three nearest linear photoacoustic detectors (3) on its left and right sides are i+1, i-1, and i+2 respectively, and the order of the two first triggered linear photoacoustic detectors (3) is i and i+1, this is called sequential triggering. If the first linear photoacoustic detector (3) triggered by the shock wave is numbered i, 3≤i≤M-1, and the numbers of the three nearest linear photoacoustic detectors (3) on its left and right sides are i-1, i-2, and i+1 respectively, and the order of the two first triggered linear photoacoustic detectors (3) is i and i-1, this is called reverse triggering. When two linear photoacoustic detectors (3) are triggered simultaneously, the triggering mode of the other two linear photoacoustic detectors (3) outside the two linear photoacoustic detectors (3) needs to be strengthened to determine whether it is simultaneous triggering, sequential triggering under simultaneous triggering, or reverse triggering under simultaneous triggering.

3. The method for measuring the impact point of a large-area supersonic non-explosive bomb according to claim 2, characterized in that: In step three, when triggered sequentially, the X-axis calculation formula is as follows: (1)， wherein d is the distance between the two linear photoacoustic detectors (3), t i-1 , t i , t i+1 , t i+2 are the trigger times of the four linear photoacoustic detectors (3), respectively. In step four, during sequential triggering, the first triggering time in the X direction... for: (2)， The same applies to the Y direction; When triggered in reverse order, the X-axis calculation formula is: (3)， Among them, t i-2 t i-1 t i t i+1 These are the trigger times corresponding to the four linear photoacoustic detectors (3); In step four, during reverse triggering, the first triggering time in the X direction... for: (4)， The same applies to the Y direction; In step three, based on the two linear photoacoustic detectors (3)i 左 i 右 and the two linear photoacoustic detectors (3)i 左 -1、i 右 +1 trigger time t i左 t i右 t i左-1 t i右+1 The formula for calculating the X-axis is: (5)， The formula for calculating the Y-axis is similar; In step four, when triggered simultaneously, the first trigger time in the X direction... The calculation formula is (6)； When triggering sequentially under simultaneous triggering, the first trigger time in the X direction. The calculation formula is (7)， When triggering in reverse order under simultaneous triggering, the first trigger time in the X direction. The calculation formula is (8)。 4. The method for measuring the impact point of a large-area supersonic non-explosive bomb according to claim 3, characterized in that: In step five, the landing point coordinates (x, y) are obtained using the following formula. (9)。

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