Laser light curtain target high-speed spherical fragment size recognition method and device

Abstract

The present application relates to the field of photoelectric detection technology, and discloses a method, device, electronic device and storage medium for size recognition of high-speed spherical fragments using a laser light curtain target, which solves the problem of non-contact size recognition of high-speed spherical fragments. The method comprises: obtaining a target-passing signal and a target-passing speed of the target spherical fragments output by a laser light curtain target test system when detecting target spherical fragments; correcting the target-passing signal of the target spherical fragments based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragments on the target-passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the speed of the high-speed spherical fragments on the target-passing signal; extracting at least two feature points and the time information corresponding to each feature point from the corrected target-passing signal; and determining the size of the target spherical fragments based on the time information corresponding to the at least two feature points and the target-passing speed of the target spherical fragments.

Description

Technical Field

[0001] The present application relates to the field of photoelectric detection technology, and in particular to a method and device for identifying the size of high-speed spherical fragments of a laser light curtain target. Background Art

[0002] The laser light curtain target test system is an intercept measurement instrument designed based on photoelectric detection principles. Its high velocity measurement accuracy, non-contact operation, and weather resistance make it a significant advantage in projectile and fragment velocity testing. However, in high-speed spherical fragment damage effectiveness testing, fragment size is often difficult to measure. Contact-based fragment size measurement methods reduce the measured fragment velocity, affecting test accuracy, while non-contact laser light curtain target test systems lack size recognition capabilities. Summary of the Invention

[0003] The embodiments of the present application provide a method, device, electronic device and storage medium for size recognition of high-speed spherical fragments using a laser light curtain target, which solve the problem of non-contact high-speed spherical fragment size recognition.

[0004] In a first aspect, an embodiment of the present application provides a method for identifying the size of high-speed spherical fragments of a laser light curtain target, comprising:

[0005] Obtaining a target-passing signal output by a laser light curtain target test system when detecting target spherical fragments and a target-passing speed of the target spherical fragments; wherein the target-passing signal is a waveform signal output by a photoelectric detector when the target spherical fragments pass through the light curtain in the laser light curtain target test system;

[0006] Correcting the target passing signal of the target spherical fragment based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragment on the target passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the speed and size of the spherical fragment on the target passing signal;

[0007] Extracting at least two feature points and time information corresponding to each feature point from the corrected target-passing signal; wherein each feature point represents a designated position of the spherical fragment passing through the light curtain;

[0008] The size of the target spherical fragments is determined based on the time information corresponding to the at least two characteristic points and the target speed of the target spherical fragments.

[0009] Optionally, the laser light curtain target test system includes two light curtains arranged at intervals, and the laser light curtain target test system outputs two target passing signals, each target passing signal corresponding to one light curtain;

[0010] The method further includes: selecting a target-passing signal with higher signal quality from the two target-passing signals based on the signal amplitude and signal-to-noise ratio of the target-passing signal;

[0011] The correcting of the target passing signal includes correcting a selected target passing signal.

[0012] Optionally, extracting at least two feature points from the corrected target-passing signal includes:

[0013] Performing first-order differential processing on the corrected target-passing signal to obtain a differential result;

[0014] At least two characteristic points are extracted from the differential result; wherein the characteristic points include: a maximum value P1, a minimum value P3, a zero point P2 between the maximum value and the minimum value, a first zero point P0 appearing before the maximum value, and a first zero point P4 appearing after the minimum value, P0 indicates that the front end of the spherical fragment enters the light curtain, P1 indicates that the front end of the spherical fragment leaves the light curtain, P2 indicates that the center of the spherical fragment reaches the center of the light curtain, P3 indicates that the rear end of the spherical fragment enters the light curtain, and P4 indicates that the rear end of the spherical fragment leaves the light curtain.

[0015] Optionally, determining the size of the target spherical fragments based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragments includes:

[0016] Combining the at least two feature points in pairs to obtain at least one feature point combination; wherein each feature point combination corresponds to a predetermined size calculation model, the size calculation model being used to represent the relationship between the fragment size and the time information of the two feature points and the target speed;

[0017] For any obtained feature point combination, substituting the time information of the two feature points contained in the any feature point combination and the target speed of the target spherical fragment into the size calculation model corresponding to the any feature point combination to obtain the estimated size of the target spherical fragment;

[0018] The size of the target spherical fragment is determined based on the estimated size corresponding to each feature point combination in the at least one feature point combination.

[0019] Optionally, the correction coefficient matrix is ​​obtained in the following manner:

[0020] Obtain theoretical target-passing signals of spherical fragments of different speeds and sizes without shock waves;

[0021] The shock waves generated by spherical fragments of different sizes and speeds are simulated using fluid mechanics numerical simulation methods to obtain the air density fields generated by spherical fragments of different sizes and speeds.

[0022] Convert the air density field generated by spherical fragments of different speeds and sizes into a refractive index field;

[0023] Based on the refractive index field of spherical fragments of different speeds and sizes, the laser ray tracing is performed on the spherical fragments of different speeds and sizes when they pass through the light curtain to obtain the disturbance signal of the spherical fragments of different speeds and sizes passing through the target when there is a shock wave;

[0024] The correction coefficient matrix is ​​established based on theoretical target-passing signals and disturbed target-passing signals of spherical fragments of different speeds and sizes.

[0025] Optionally, in the process of establishing the correction coefficient matrix, the velocity of the spherical fragments ranges from 500 to 2500 m / s, and the size of the spherical fragments ranges from 4 to 20 mm.

[0026] In a second aspect, an embodiment of the present application provides a laser light curtain target high-speed spherical fragment size recognition device, comprising:

[0027] an acquisition module, configured to acquire a target-passing signal output by a laser light curtain target test system when detecting target spherical fragments and a target-passing speed of the target spherical fragments; wherein the target-passing signal is a waveform signal output by a photoelectric detector when the target spherical fragments pass through the light curtain in the laser light curtain target test system;

[0028] a correction module, configured to correct the target passing signal of the target spherical fragments based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragments on the target passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the velocity of the high-speed spherical fragments on the target passing signal;

[0029] A feature extraction module is used to extract at least two feature points and time information corresponding to each feature point from the corrected target passing signal; wherein each feature point represents a specified position of the spherical fragment passing through the light curtain;

[0030] The size calculation module is used to determine the size of the target spherical fragment based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragment.

[0031] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.

[0032] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon, which implement the steps of any of the above methods when executed by a processor.

[0033] In a fifth aspect, embodiments of the present application provide a computer program product or computer program, comprising computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method provided in any of the aforementioned various optional implementations of controlling TCP transmission performance.

[0034] The embodiments of the present application provide a method, device, electronic device, and storage medium for identifying the size of high-speed spherical fragments using a laser light curtain target. The method obtains the target passing signal and target passing velocity of the high-speed spherical fragments through a laser light curtain target test system, corrects the target passing signal based on a pre-obtained correction coefficient matrix to remove the influence of the shock wave generated by the high-speed spherical fragments on the target passing signal, and then extracts feature points related to the motion position of the high-speed spherical fragments from the corrected target passing signal. The size of the target spherical fragments is determined based on the time information of the feature points and the target passing velocity of the target spherical fragments, thereby solving the problem of non-contact high-speed spherical fragment size identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings introduced below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a schematic diagram of the test principle of an existing laser light curtain target test system;

[0037] Figure 2 A schematic flow chart of a method for identifying the size of high-speed spherical fragments using a laser light curtain target according to an embodiment of the present application;

[0038] Figure 3 A schematic diagram of a process for establishing a correction coefficient matrix according to an embodiment of the present application;

[0039] Figure 4A A schematic diagram of the positional relationship between the spherical fragments and the light curtain at different moments during the target passing process provided by an embodiment of the present application;

[0040] Figure 4B for Figure 4A The theoretical target passing signal of spherical fragments passing through the light curtain;

[0041] Figure 4C for Figure 4B The first-order differential result of the theoretical over-target signal in ;

[0042] Figure 5A This is the target passing signal of a spherical fragment collected by the laser light curtain target test system;

[0043] Figure 5B for Figure 5A The first-order differential processing result of the target-crossing signal in ;

[0044] Figure 6 Distribution diagram of the air density field generated by spherical fragments of the same size and different speeds;

[0045] Figure 7 This is the distribution diagram of the surrounding air density field caused by the shock wave generated by high-speed spherical fragments;

[0046] Figure 8 Schematic diagram of the disturbance of the light curtain caused by the shock wave of high-speed spherical fragments;

[0047] Figure 9A This is a schematic diagram showing that low-speed spherical fragments have almost no effect on the light curtain when passing through the light curtain;

[0048] Figure 9B This is a schematic diagram showing the impact of high-speed flying spherical fragments on the light curtain when passing through the light curtain. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Although the embodiments of the present application provide method operation steps as shown in the following embodiments or drawings, more or fewer operation steps may be included in the method based on conventional or no creative labor. In the steps where there is no necessary causal relationship logically, the execution order of these steps is not limited to the execution order provided in the embodiments of the present application. Any number of elements in the drawings is for example and not for limitation, and any naming is only for distinction and does not have any limiting meaning.

[0050] refer to Figure 1 The laser light curtain target test system consists of two sets of photoelectric detection units. Each set of photoelectric detection units includes a photoelectric transceiver module, a lens, a reflective screen, a photoelectric signal conditioning module, and a high-speed signal acquisition module. The photoelectric transceiver module includes a laser transmitter module and a photodetector. The laser emitted by the laser transmitter module is shaped by the lens and then directed to the reflective screen at the other end, forming a light curtain between the lens and the reflective screen. The light curtain has a certain thickness in the direction of movement of the spherical fragments. This thickness is called the light curtain thickness δ. Figure 4A. The laser is reflected by the reflective screen and received by the photoelectric detector and converted into an electrical signal output. The output electrical signal is processed by the photoelectric signal conditioning module and then collected and output by the high-speed signal acquisition module. The light curtains formed by the two groups of photoelectric detection units are the start target laser light curtain and the stop target laser light curtain. The start target laser light curtain and the stop target laser light curtain are sequentially assembled in front of the muzzle along the path of the projectile and fragment launch direction. The distance between the two is determined, which is called the laser light curtain target distance. When the fragments pass through the light curtain, they will block part of the laser, thereby reducing the laser reaching the photoelectric detector, causing the signal amplitude output by the photoelectric detector to change. The signal collected by the high-speed signal acquisition module during the process of the fragments passing through the light curtain is the target passing signal, refer to Figure 5A This is the target-passing signal of a spherical fragment collected by the laser light curtain target test system. The laser light curtain target test system starts timing when the spherical fragment passes through the start target laser light curtain and stops timing when the spherical fragment passes through the stop target laser light curtain. The target-passing speed is calculated based on the time difference between the start target laser light curtain and the stop target laser light curtain, as well as the laser light curtain target distance.

[0051] It should be noted that the laser light curtain target test system used in the embodiments of the present application can be a laser light curtain speed measurement system in the prior art.

[0052] refer to Figure 2 The embodiment of the present application provides a method for identifying the size of high-speed spherical fragments of a laser light curtain target, comprising the following steps:

[0053] S201, obtaining a target passing signal output by a laser light curtain target testing system when detecting target spherical fragments and a target passing speed of the target spherical fragments.

[0054] The target passing signal is the waveform signal output by the photoelectric detector when the target spherical fragment passes through the light curtain in the laser light curtain target test system.

[0055] In a specific implementation, when the target spherical fragments pass through the light curtain in the laser light curtain target test system, the laser light curtain target test system collects and outputs the target passing signal and target passing speed of the target spherical fragments.

[0056] Since the laser light curtain target test system includes two light curtains arranged at intervals, the laser light curtain target test system will output two target passing signals, and each target passing signal corresponds to one light curtain.

[0057] In some embodiments, based on the signal amplitude and signal-to-noise ratio of the target-passing signal, the target-passing signal with higher signal quality is selected from the two target-passing signals, and then the selected target-passing signal is corrected, while the other target-passing signal is discarded and not processed. Specifically, the target-passing signal with higher signal amplitude and higher signal-to-noise ratio can be selected from the two target-passing signals; or, when the signal amplitude of one target-passing signal is high and the signal-to-noise ratio of the other target-passing signal is high, the signal amplitude and signal-to-noise ratio of each target-passing signal can be scored separately, and the scores of the signal amplitude and signal-to-noise ratio are weighted and summed to obtain the signal quality score of each target-passing signal, and the target-passing signal with higher signal quality score is selected for correction. Through the above-mentioned signal quality adaptive discrimination algorithm, the target-passing signal with higher quality is selected from the two target-passing signals to participate in the size recognition of spherical fragments, which helps to improve the accuracy of fragment size recognition.

[0058] In other embodiments, the two target passing signals can be corrected and feature points extracted separately, and then the fragment size can be determined based on the feature points of each target passing signal and the target passing speed of the target spherical fragments. The fragment sizes corresponding to the two target passing signals are then combined to obtain the final size of the target spherical fragments.

[0059] S202 : Correct the target passing signal of the target spherical fragments based on the correction coefficient matrix obtained in advance, so as to remove the influence of the shock wave generated by the target spherical fragments on the target passing signal.

[0060] The correction coefficient matrix is ​​used to represent the influence of the velocity of high-speed spherical fragments on the target passing signal.

[0061] In some embodiments, reference Figure 3 , the correction coefficient matrix can be obtained as follows:

[0062] S301. Obtain theoretical target-passing signals of spherical fragments of different speeds and sizes in the absence of shock waves.

[0063] In specific implementation, by analyzing the target passing process of spherical fragments, establishing a model, and simulating the theoretical target passing signal, we can obtain the theoretical target passing signal of spherical fragments of different speeds and sizes, that is, the target passing signal without the influence of shock waves. The theoretical target passing signal is related to the size of the spherical fragments, the target passing speed, and the thickness of the light curtain. Figure 4AAt T0, the front end of the spherical fragment moves to the extreme left of the light curtain, indicating that the front end of the spherical fragment has just begun to enter the light curtain, that is, the entire spherical fragment begins to enter the light curtain area; at T1, the front end of the spherical fragment moves to the extreme right of the light curtain, indicating that the front end of the spherical fragment leaves the light curtain; at T2, the center of the spherical fragment moves to the center of the light curtain; at T3, the rear end of the spherical fragment moves to the extreme left of the light curtain, indicating that the rear end of the spherical fragment has just begun to enter the light curtain; at T4, the rear end of the spherical fragment moves to the extreme right of the light curtain, indicating that the rear end of the spherical fragment leaves the light curtain, that is, the entire spherical fragment completely leaves the light curtain area. Figure 4A The positional relationship between the spherical fragments and the light curtain can be used to calculate the blocking area of ​​the light curtain by the spherical fragments at different times. Since the blocking area is positively correlated with the target passing signal, the following can be obtained based on the blocking area of ​​the light curtain by the spherical fragments at different times: Figure 4B Theoretical over-target signal is shown.

[0064] Further, Figure 4B The theoretical target signal shown in the figure is processed by first-order differential to obtain Figure 4C The first-order differential results shown in FIG. 3 can be used to determine multiple characteristic points by analyzing the first-order differential results of the theoretical target-passing signals of spherical fragments of different speeds and sizes. Each characteristic point represents the position of the spherical fragment passing through the light curtain. For example, the maximum value P1 (corresponding to Figure 4C The point at time T1 in the Figure 4C The point at time T3 in the figure), the zero point P2 between the maximum and minimum values ​​(corresponding to Figure 4C The first zero point P0 before the maximum value (corresponding to the T2 point in Figure 4C The point at time T0 in the graph) and the first zero point P4 after the minimum value (corresponding to Figure 4C The points at time T4 in the figure are used as feature points. P0 indicates when the front end of the spherical fragment enters the light curtain, P1 indicates when the front end of the spherical fragment leaves the light curtain, P2 indicates when the center of the spherical fragment reaches the center of the light curtain, P3 indicates when the rear end of the spherical fragment enters the light curtain, and P4 indicates when the rear end of the spherical fragment leaves the light curtain. It should be noted that the front and rear ends of the spherical fragment are based on the flight direction of the spherical fragment. The front end refers to the end of the spherical fragment that first enters the light curtain during flight, and the rear end refers to the end of the spherical fragment that last enters the light curtain during flight.

[0065] S302. Using a fluid mechanics numerical simulation method, simulate the shock waves generated by spherical fragments of different speeds and sizes to obtain the air density fields generated by the spherical fragments of different speeds and sizes.

[0066] In the embodiments of this application, a shock wave refers to a compression wave in a gas medium, characterized by a sudden change in stress (or pressure), density, and temperature on the wavefront. This wave, also known as a shock wave, occurs in processes such as supersonic flow and explosions. High-speed spherical fragments cause changes in the surrounding air density, generating shock waves. When these fragments pass through the light curtain, the shock waves deflect the laser beam, affecting the target-passing signal output by the system.

[0067] In specific implementation, the k-ε turbulence model, Reynolds stress averaging (RANS) and other fluid mechanics numerical simulation methods can be used to simulate the shock waves generated by high-speed spherical fragments. The specific simulation process is an existing technology and will not be described in detail. The simulation results can be referred to Figure 6 , the simulation diagrams of the air density field around the spherical fragments at speeds of 1000m / s, 1500m / s, 2000m / s and 2500m / s are given.

[0068] S303. Convert the air density field generated by spherical fragments of different speeds and sizes into a refractive index field.

[0069] In specific implementation, the Gladstone-Dale law of gas refractive index can be used, that is, N=1+K GD ρ, converts the air density field generated by the spherical fragments into a refractive index field. The specific conversion process is based on existing technology and will not be described in detail.

[0070] S304. Based on the refractive index fields of spherical fragments of different sizes and different speeds, ray tracing is performed on the laser beam when the spherical fragments of different sizes and different speeds pass through the light curtain to obtain disturbance signals of the spherical fragments of different sizes and different speeds passing through the target when there is a shock wave.

[0071] Figure 7 The distribution diagram of the surrounding air density field caused by the shock wave generated by high-speed spherical fragments is shown in Figure 2. The air density is distributed in a gradient from the outside to the inside. For air, its refractive index and density satisfy the Gladstone-Dale law (linear correlation), that is, the refractive index field of high-speed spherical fragments is also Figure 7 The Runge-Kutta-based ray tracing method is used to calculate the optical transmission effect of the flow field. Figure 7 Reference for tracking Figure 8 , Figure 7 The corresponding refractive index field is Figure 8 The refractive index contour lines represent that the incident light refracts according to the law of refraction whenever it passes through the refractive index contour lines with varying refractive index. The incident light refracts in the air density field with varying refractive index and gradually deviates from the original direction. Through parameterized sweeping, the target passing signal of high-speed spherical fragments with shock waves is finally obtained, which is recorded as the disturbed target passing signal. The disturbed target passing signal can be referred to Figure 5A .

[0072] refer to Figure 9A , low-speed flying spherical fragments have no effect on the light curtain when passing through the light curtain, refer to Figure 9B When spherical fragments flying at a speed of 500m / s pass through the light curtain, they cause obvious disturbance to the light curtain.

[0073] S305: Establish a correction coefficient matrix based on theoretical target-passing signals and disturbed target-passing signals of spherical fragments of different speeds and sizes.

[0074] In specific implementations, for spherical fragments of a certain size and velocity, the deviation between the theoretical and disturbed target-passing signals of the spherical fragments is determined. Based on this deviation, a correction factor is then determined to eliminate the effects of shock waves. A correction factor matrix is ​​established based on the correction factors corresponding to spherical fragments of different sizes and velocities. This correction factor matrix thus includes correction factors for spherical fragments of various sizes and velocities.

[0075] In practical applications, when the size range is small (4-20mm), the impact of the size of high-speed fragments on the target-passing signal is only manifested in scale, which can be understood as the linear scaling of the waveform in the amplitude and time dimensions. Therefore, it is only necessary to correct the target-passing signal according to the speed, that is, only the correspondence between each speed and the correction coefficient in the correction coefficient matrix is ​​retained. The correction coefficient corresponding to each speed represents the impact of the speed of the high-speed spherical fragment on the target-passing signal.

[0076] When using the correction coefficient matrix to correct the target passing signal of the target spherical fragment, the correction coefficient corresponding to the target passing speed is selected from the correction coefficient matrix according to the target passing speed of the target spherical fragment. The target passing signal of the target spherical fragment is corrected based on the selected correction coefficient to remove the influence of the shock wave generated by the target spherical fragment on the target passing signal.

[0077] In a specific implementation, in the process of establishing the correction coefficient matrix, the velocity of the spherical fragments ranges from 500 to 2500 m / s, and the size of the spherical fragments ranges from 4 to 20 mm.

[0078] By analyzing the influence of shock waves generated by high-speed spherical fragments on the light curtain, a correction coefficient matrix is ​​obtained to describe the relationship between the influence of shock waves on the light curtain and the size and speed of spherical fragments. Based on the correction coefficient matrix, the actually measured target-passing signals of high-speed spherical fragments are corrected to eliminate the influence of shock waves on the target-passing signals, reduce the interference of shock waves on feature point extraction, and thus improve the size recognition accuracy of high-speed fragments.

[0079] S203 : Extract at least two feature points and time information corresponding to each feature point from the corrected target passing signal.

[0080] Each feature point represents the time when a spherical fragment passes through the light curtain at a specified position. The time information corresponding to each feature point refers to the time when the feature point passes through the target signal. Figure 5A 、 Figure 5B .

[0081] In some embodiments, a first-order differential process is performed on the corrected over-target signal to obtain a differential result, and at least two feature points are extracted from the differential result. The feature points extracted from the differential result may include at least two of the maximum value P2, the minimum value P4, the zero point P3 between the maximum value and the minimum value, the first zero point P1 appearing before the maximum value, and the first zero point P5 appearing after the minimum value. For example, Figure 5B The first-order differential processing result of the target passing signal is used to extract at least two feature points, and the horizontal coordinate values ​​of the extracted feature points are used as the time information of the feature points. The method for extracting the feature points is conventional and will not be described in detail. After performing the first-order differential processing on the target passing signal, the feature points can be extracted from the target passing signal more conveniently.

[0082] S204: Determine the size of the target spherical fragments based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragments.

[0083] In specific implementation, the target-passing process of the spherical fragments can be analyzed to pre-establish the relationship between the time information of the two characteristic points, the target-passing speed of the spherical fragments and the size of the spherical fragments. In step S204, the time information corresponding to at least two characteristic points and the target-passing speed of the target spherical fragments can be substituted into the above-mentioned predetermined relationship to obtain the size of the target spherical fragments.

[0084] refer to Figure 4A The geometric relationship between the spherical fragments and the light curtain at time T0 to T4 can be used to obtain the time information of the two feature points, the relationship between the speed of the spherical fragments passing the target and the size of the spherical fragments, which is recorded as the size calculation model. For example, the size calculation model may include:

[0085] D=v(T3-T0), D=v(T4-T0)-δ, D=v(T3-T1)+δ, D=v(T4-T1), Etc., where D represents the diameter of the spherical fragments, i.e., the size of the spherical fragments, v represents the target speed of the spherical fragments, and δ is the thickness of the light curtain.

[0086] By analyzing and modeling the target-passing process of spherical fragments, and simulating and differentially processing the theoretical target-passing signal, the motion state of the spherical fragments is associated with the moment of the characteristic points, and then a size calculation model is obtained, so that the size of the spherical fragments can be quickly calculated based on a few characteristic points.

[0087] In some embodiments, step S204 specifically includes: combining at least two feature points in pairs to obtain at least one feature point combination, wherein each feature point combination corresponds to a predetermined size calculation model, and the size calculation model is used to represent the relationship between the fragment size and the time information of the two feature points and the target speed; for any feature point combination obtained, substituting the time information of the two feature points contained in the feature point combination and the target speed of the target spherical fragment into the size calculation model corresponding to the feature point combination to obtain the estimated size of the target spherical fragment; based on the estimated size corresponding to each feature point combination in the at least one feature point combination, determine the size of the target spherical fragment.

[0088] For example, three feature points P2, P3, and P4 are extracted through step S203, and two feature point combinations P2 and P3, and P2 and P4 can be obtained; the time information of P2 and P3 and the target spherical fragment speed are substituted into the formula Get the estimated size D1 of the target spherical fragment; substitute the time information and target speed of P2 and P4 into the formula Obtain the estimated size D2 of the target spherical fragment; calculate the average of D1 and D2 as the size of the target spherical fragment. By combining multiple feature points, multiple estimated sizes of the target spherical fragment are obtained, and then the average of these multiple estimated sizes is calculated to reduce the impact of errors.

[0089] Based on the laser light curtain target test system and the above-mentioned laser light curtain target high-speed spherical fragment size recognition method, the size of spherical fragments of known size is recognized to verify the effectiveness of the laser light curtain target high-speed spherical fragment size recognition method. After implementation, it is found that the recognition accuracy of the verification laser light curtain target high-speed spherical fragment size recognition method provided in the embodiment of this application is <0.1mm, and the error is <5%.

[0090] The laser light curtain target high-speed spherical fragment size identification method of the embodiment of the present application obtains the target passing signal and target passing speed of the high-speed spherical fragment through the laser light curtain target test system, corrects the target passing signal based on the pre-obtained correction coefficient matrix to remove the influence of the shock wave generated by the high-speed spherical fragment on the target passing signal, and then extracts the feature points related to the movement position of the high-speed spherical fragment from the corrected target passing signal, and determines the size of the target spherical fragment based on the time information of the feature points and the target passing speed of the target spherical fragment, thereby solving the problem of non-contact high-speed spherical fragment size identification and having the advantage of low size identification accuracy error.

[0091] Based on the same inventive concept as the above-mentioned laser light curtain target high-speed spherical fragment size identification method, the embodiment of the present application also provides a laser light curtain target high-speed spherical fragment size identification device, including: an acquisition module, a correction module, a feature extraction module and a size calculation module.

[0092] an acquisition module, configured to acquire a target-passing signal output by a laser light curtain target test system when detecting target spherical fragments and a target-passing speed of the target spherical fragments; wherein the target-passing signal is a waveform signal output by a photoelectric detector when the target spherical fragments pass through the light curtain in the laser light curtain target test system;

[0093] a correction module, configured to correct the target passing signal of the target spherical fragments based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragments on the target passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the velocity of the high-speed spherical fragments on the target passing signal;

[0094] A feature extraction module is used to extract at least two feature points and time information corresponding to each feature point from the corrected target passing signal; wherein each feature point represents a specified position of the spherical fragment passing through the light curtain;

[0095] The size calculation module is used to determine the size of the target spherical fragment based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragment.

[0096] Optionally, the laser light curtain target test system includes two light curtains arranged at intervals, and the laser light curtain target test system outputs two target passing signals, each target passing signal corresponding to one light curtain; the laser light curtain target high-speed spherical fragment size identification device also includes a signal filtering module, which is used to select a target passing signal with higher signal quality from the two target passing signals based on the signal amplitude and signal-to-noise ratio of the target passing signal; the correction module is specifically used to: correct the selected target passing signal based on a pre-obtained correction coefficient matrix.

[0097] Optionally, the feature extraction module is specifically used to: perform first-order differential processing on the corrected over-target signal to obtain a differential result; extract at least two feature points from the differential result; wherein the feature points include: a maximum value P1, a minimum value P3, a zero point P2 between the maximum value and the minimum value, the first zero point P0 appearing before the maximum value, and the first zero point P4 appearing after the minimum value, P0 indicates that the front end of the spherical fragment enters the light curtain, P1 indicates that the front end of the spherical fragment leaves the light curtain, P2 indicates that the center of the spherical fragment reaches the center of the light curtain, P3 indicates that the rear end of the spherical fragment enters the light curtain, and P4 indicates that the rear end of the spherical fragment leaves the light curtain.

[0098] Optionally, the size calculation module is specifically used to: combine the at least two feature points in pairs to obtain at least one feature point combination; wherein each feature point combination corresponds to a predetermined size calculation model, and the size calculation model is used to represent the relationship between the fragment size and the time information of the two feature points and the target speed; for any feature point combination obtained, the time information of the two feature points contained in the any feature point combination and the target speed of the target spherical fragment are substituted into the size calculation model corresponding to the any feature point combination to obtain the estimated size of the target spherical fragment; based on the estimated size corresponding to each feature point combination in the at least one feature point combination, the size of the target spherical fragment is determined.

[0099] The laser light curtain target high-speed spherical fragment size identification device proposed in the embodiment of the present application adopts the same inventive concept as the above-mentioned laser light curtain target high-speed spherical fragment size identification method and can achieve the same beneficial effects, which will not be repeated here.

[0100] Based on the same inventive concept as the above-mentioned laser light curtain target high-speed spherical fragment size identification method, an embodiment of the present application also provides an electronic device, which may include a processor and a memory.

[0101] The processor may be a general-purpose processor, such as a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, and may implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. A general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0102] As a non-volatile computer-readable storage medium, memory can be used to store non-volatile software programs, non-volatile computer executable programs and modules.Memory can include at least one type of storage medium, for example, can include flash memory, hard disk, multimedia card, card-type memory, random access memory (Random Access Memory, RAM), static random access memory (Static Random Access Memory, SRAM), programmable read-only memory (Programmable Read Only Memory, PROM), read-only memory (Read Only Memory, ROM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), magnetic storage, disk, optical disk, etc. Memory is any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory in the embodiment of the present application can also be a circuit or other arbitrarily capable of implementing a storage function, for storing program instructions and / or data.

[0103] Those skilled in the art will appreciate that all or part of the steps of the above-mentioned method embodiments may be implemented by hardware associated with program instructions, and the aforementioned program may be stored in a computer-readable storage medium. When the program is executed, the program executes the steps of the above-mentioned method embodiments. The above-mentioned computer storage medium may be any available medium or data storage device that can be accessed by a computer, including but not limited to: mobile storage devices, random access memory (RAM), magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (such as ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid-state drives (SSDs)), and other media that can store program codes.

[0104] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: a mobile storage device, a random access memory (RAM, Random Access Memory), a magnetic storage device (such as a floppy disk, a hard disk, a magnetic tape, a magneto-optical disk (MO), etc.), an optical storage device (such as a CD, DVD, BD, HVD, etc.), and a semiconductor memory (such as a ROM, EPROM, EEPROM, a non-volatile memory (NAND FLASH), a solid-state drive (SSD)) and other various media that can store program code.

[0105] The above embodiments are only used to provide a detailed introduction to the technical solutions of the present application. However, the description of the above embodiments is only used to help understand the methods of the embodiments of the present application and should not be understood as limiting the embodiments of the present application. Any changes or substitutions that can be easily conceived by those skilled in the art should be included in the scope of protection of the embodiments of the present application.

Claims

1. A method for identifying the size of high-speed spherical fragments of a laser light curtain target, characterized in that: include: Obtaining a target-passing signal output by a laser light curtain target test system when detecting target spherical fragments and a target-passing speed of the target spherical fragments; wherein the target-passing signal is a waveform signal output by a photoelectric detector when the target spherical fragments pass through the light curtain in the laser light curtain target test system; Correcting the target passing signal of the target spherical fragments based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragments on the target passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the velocity of the high-speed spherical fragments on the target passing signal; Extracting at least two feature points and time information corresponding to each feature point from the corrected target-passing signal; wherein each feature point represents a designated position of the spherical fragment passing through the light curtain; determining the size of the target spherical fragments based on the time information corresponding to the at least two characteristic points and the target speed of the target spherical fragments; The step of extracting at least two feature points from the corrected target-passing signal comprises: Performing first-order differential processing on the corrected target-passing signal to obtain a differential result; Extract at least two characteristic points from the differential result; wherein the characteristic points include: a maximum value P1, a minimum value P3, a zero point P2 between the maximum value and the minimum value, a first zero point P0 appearing before the maximum value, and a first zero point P4 appearing after the minimum value, the moment corresponding to P0 is the moment when the front end of the spherical fragment enters the light curtain, the moment corresponding to P1 is the moment when the front end of the spherical fragment leaves the light curtain, the moment corresponding to P2 is the moment when the center of the spherical fragment reaches the center of the light curtain, the moment corresponding to P3 is the moment when the rear end of the spherical fragment enters the light curtain, and the moment corresponding to P4 is the moment when the rear end of the spherical fragment leaves the light curtain; The determining the size of the target spherical fragments based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragments includes: Combining the at least two feature points in pairs to obtain at least one feature point combination; wherein each feature point combination corresponds to a predetermined size calculation model, the size calculation model being used to represent the relationship between the fragment size and the time information of the two feature points and the target speed; For any obtained feature point combination, substituting the time information of the two feature points contained in the any feature point combination and the target speed of the target spherical fragment into the size calculation model corresponding to the any feature point combination to obtain the estimated size of the target spherical fragment; determining the size of the target spherical fragment based on the estimated size corresponding to each feature point combination in the at least one feature point combination; The correction coefficient matrix is ​​obtained as follows: Obtain theoretical target-passing signals of spherical fragments of different speeds and sizes without shock waves; The shock waves generated by spherical fragments of different sizes and speeds are simulated using fluid mechanics numerical simulation methods to obtain the air density fields generated by spherical fragments of different sizes and speeds. Convert the air density field generated by spherical fragments of different speeds and sizes into a refractive index field; Based on the refractive index field of spherical fragments of different speeds and sizes, the laser ray tracing is performed on the spherical fragments of different speeds and sizes when they pass through the light curtain to obtain the disturbance signal of the spherical fragments of different speeds and sizes passing through the target when there is a shock wave; The correction coefficient matrix is ​​established based on theoretical target-passing signals and disturbed target-passing signals of spherical fragments of different speeds and sizes.

2. The method according to claim 1, characterized in that The laser light curtain target test system includes two light curtains arranged at intervals, and the laser light curtain target test system outputs two target passing signals, each target passing signal corresponds to one light curtain; The method further includes: selecting a target-passing signal with higher signal quality from the two target-passing signals based on the signal amplitude and signal-to-noise ratio of the target-passing signal; Correcting the target passing signal includes correcting a selected target passing signal.

3. The method according to claim 1, characterized in that In the process of establishing the correction coefficient matrix, the velocity of the spherical fragments ranges from 500 to 2500 m / s, and the size of the spherical fragments ranges from 4 to 20 mm.

4. A laser light curtain target high-speed spherical fragment size identification device, characterized in that: The steps for performing the method according to any one of claims 1 to 3 include: an acquisition module, configured to acquire a target-passing signal output by a laser light curtain target test system when detecting target spherical fragments and a target-passing speed of the target spherical fragments; wherein the target-passing signal is a waveform signal output by a photoelectric detector when the target spherical fragments pass through the light curtain in the laser light curtain target test system; a correction module, configured to correct the target passing signal of the target spherical fragments based on a pre-acquired correction coefficient matrix to remove the influence of the shock wave generated by the target spherical fragments on the target passing signal; wherein the correction coefficient matrix is ​​used to represent the influence of the velocity of the high-speed spherical fragments on the target passing signal; A feature extraction module is used to extract at least two feature points and time information corresponding to each feature point from the corrected target passing signal; wherein each feature point represents a specified position of the spherical fragment passing through the light curtain; The size calculation module is used to determine the size of the target spherical fragment based on the time information corresponding to the at least two feature points and the target speed of the target spherical fragment.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 3 are implemented.

6. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the steps of the method according to any one of claims 1 to 3 are implemented.

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