Bulletproof helmet detection method and device

Abstract

The invention provides a bulletproof helmet detection method and device. According to the bulletproof helmet detection method, a laser dot matrix is irradiated on the inner surface of a to-be-detected helmet, initial position information and real-time position information of each laser point position in the laser dot matrix are measured to obtain a real-time displacement vector of the laser dot matrix, and then the real-time displacement vector can be used for judging the deformation condition of the to-be-detected helmet. Meanwhile, in consideration of the fact that the helmet to be tested possibly generates rigid displacement during testing, a component with the minimum absolute value is screened out from the real-time displacement vectors, and the component is subtracted from each component in the real-time displacement vectors to obtain a real displacement vector of the laser dot matrix, so that the influence of the rigid displacement of the helmet to be tested on the actual deformation is filtered out, and the measurement accuracy is improved. The measurement precision is improved. The invention further provides a detection device which is used for realizing the detection method, and the laser light source and the image sensor are integrated into the supporting assembly, so that the internal deformation of the helmet to be detected is measured.

Description

Technical Field

[0001] The present invention relates to the technical field of helmet detection, and in particular to a method and device for detecting a bulletproof helmet. Background Art

[0002] With the continuous development of bulletproof materials, current high-performance bulletproof helmets can block bullet penetration with lighter weight and protect against bullet impacts at higher speeds. However, this means that the energy transmitted to the human body through bulletproof equipment may increase, thereby increasing the probability of serious non-penetrating injuries to the human body. Therefore, when evaluating and testing the performance of bulletproof equipment, it is necessary not only to examine its bulletproof ability but also its impact resistance. Usually, during the test, the helmet needs to be fixed on a bracket with a shape close to that of a human head for impact testing, and the impact resistance of the helmet is judged by measuring the permanent deformation of the helmet after the impact. However, when the helmet is subjected to high-speed impact, the deformation process of the impacted position first increases sharply, then decreases rapidly, and finally gradually stabilizes to the permanent deformation. Measuring only the permanent deformation of the helmet has a large deviation from the maximum deformation that actually occurs when the helmet is impacted, and cannot accurately reflect the impact resistance of the helmet.

[0003] In the prior art CN111043981A, a device for detecting surface deformation of an object using a mesh laser emitter and an image acquisition device is disclosed, which uses the image acquisition device to obtain a laser projection image and compares the laser projection image with a pre-stored standard image to determine whether the surface is deformed. This test method requires a high-speed camera to quickly acquire images.

[0004] When a helmet is deformed by a bullet impact, the deformation of its outer surface is usually smaller than that of its inner surface. This is more obvious in helmets made of multi-layer fiber structures. Therefore, when testing the anti-ballistic performance of a helmet, the deformation of its inner surface is usually measured. However, since high-speed cameras are large in size and require a suitable viewing angle to truly record the impact process of the helmet, the entire test system is complex and large, making it impossible for the tested helmet to be fixed on a bracket that is close to the shape of a human head for testing, affecting the accuracy of the test results. Summary of the invention

[0005] In order to solve the technical problem that the high-speed camera in the image recognition test method is large in size and the helmet cannot be fixed on a bracket with a shape close to that of a human head, the present application provides a bulletproof helmet detection method and device.

[0006] Among them, the bulletproof helmet detection method includes the following steps: S1. Use a laser light source to form a laser dot matrix on the inner surface of the helmet to be tested; S2. Obtaining the initial position information of each laser point in the laser dot matrix reflected by the helmet to be tested , forming the initial position vector ; S3, periodically obtain the real-time position information of each laser point in the laser dot matrix reflected by the helmet to be tested , forming the real-time position vector ; S4, according to the initial position vector and the real-time position vector at adjacent moments Calculate the real-time displacement vector of the laser dot array ; S5. From the real-time displacement vector Filter out the component with the smallest absolute value from all the components; S6, the real-time displacement vector By subtracting the component with the smallest absolute value from each component in , the real displacement vector of the laser dot array can be obtained.

[0007] The present application obtains the real-time displacement vector of the laser dot matrix by irradiating the inner surface of the helmet to be tested, measuring the initial position information and real-time position information of each laser point in the laser dot matrix, and then can be used to judge the deformation of the helmet to be tested. At the same time, considering that the helmet to be tested may undergo rigid displacement during the test, the component with the smallest absolute value is screened out in the real-time displacement vector, and this component is subtracted from each component in the real-time displacement vector to obtain the real displacement vector of the laser dot matrix, thereby filtering out the influence of the rigid displacement of the helmet to be tested on the actual deformation and improving the measurement accuracy.

[0008] Specifically, the initial position information is obtained through an image sensor, and the image sensor includes a photosensitive element and an objective lens; The initial position information is obtained by the following steps: S11, obtaining the projection coordinates of the light reflected by each laser point on the photosensitive element; S12, calculating and obtaining the initial position information of each laser point according to the projection coordinates, the relative position of the photosensitive element and the laser, and the relative position of the objective lens and the photosensitive element.

[0009] The triangulation method uses the geometric relationship between the reflected light and the receiver to calculate the distance. It has the characteristics of fast response speed and high accuracy, and is suitable for rapid measurement of dynamic targets.

[0010] Specifically, in some embodiments, in step S12, the initial position information of each laser point is Calculated by the following formula:

[0011] In the formula, is the distance between the projection of the laser point on the photosensitive element and the objective lens in the first direction, is the distance between the photosensitive element and the objective lens in the second direction, is the distance between the projection of the laser point on the photosensitive element and the laser light source in the first direction, is the distance between the laser light source and the photosensitive element in the second direction, is the angle between the laser point and the optical axis of the laser light source, and the first direction is perpendicular to the second direction.

[0012] Direct triangulation distance measurement is adopted, that is, the laser beam is vertically irradiated on the inner surface of the helmet to be tested, which is convenient for the arrangement of the laser light source and the image sensor to detect the center of the light spot, thereby improving the detection accuracy.

[0013] Furthermore, in step S3, the real-time position information of each laser point Obtained by the following formula:

[0014] In the formula, is the displacement of the projection of the laser point on the photosensitive element at time t.

[0015] In some embodiments, in step S12, the initial position information of each laser point is Calculated by the following formula:

[0016] In the formula, is the distance between the projection of the laser point on the photosensitive element and the objective lens in the first direction, is the distance between the photosensitive element and the objective lens in the second direction, is the distance between the projection of the laser point on the photosensitive element and the laser light source in the first direction, is the distance between the laser light source and the photosensitive element in the second direction, It is the angle between the laser light source irradiating the laser point and the plane where the photosensitive element is located, and the first direction is perpendicular to the second direction.

[0017] The oblique illumination triangulation method is used for ranging. The laser beam illuminates the inner surface of the helmet to be tested at a certain angle, which has a higher resolution.

[0018] Furthermore, in step S3, the real-time position information of each laser point Obtained by the following formula:

[0019] In the formula, is the displacement of the projection of the laser point on the photosensitive element at time t.

[0020] Specifically, the displacement of the projection of the laser point on the photosensitive element Obtain it by following these steps: S21, number each laser point and record The initial coordinate information of each laser point at the moment forms the initial coordinate data set of the laser dot array ; S22. Periodic Recording The coordinate information of the projection of each laser point on the photosensitive element at the moment forms a real-time coordinate data set ; S23, for each of the laser points, Find the real-time coordinate data set at the time The coordinate information at the moment is the closest to the coordinate information, that is, the laser point is at The coordinates at the moment, thereby forming a real-time coordinate data set of the laser dot array ; S24, each of the laser points is located at The coordinates of the moment are the same as the laser point The distance of the coordinates at the time is the distance of the laser point at The displacement of the projection on the photosensitive element at the moment .

[0021] The position of the laser point reflected on the image sensor is different each time it is collected, so the position of the laser point collected each time needs to be matched one by one. Considering that the deformation process of the helmet to be tested is continuously changing, when the image sensor collects the position of the laser point at two adjacent time points, the position change of the laser point is small. The coordinate information with the closest distance can be found in the real-time coordinate data set obtained at two adjacent moments. This coordinate information is the coordinate information after the change of this laser point.

[0022] Specifically, the steps for numbering each laser point are as follows: S31, numbering pixels of the photosensitive element according to their row and column numbers; S32, in At a certain moment, when the projection of the laser point on the photosensitive element falls on a certain pixel, the number of the pixel is used as the number of the laser point.

[0023] Specifically, in step S23, the steps of finding the coordinate information with the closest distance are as follows: S41, in At a certain moment, when the projection of the laser point on the photosensitive element falls on a certain pixel, the number of the pixel is recorded; S42, in Real-time coordinate data set at the moment In the real-time coordinate data set, the pixel number is used as the starting point, and the adjacent numbers are searched one by one from near to far until the pixel number is found. The number that exists in The coordinate information of the laser point at the time is recorded as the laser point corresponding to this number at Coordinate information at the time.

[0024] When searching for the coordinate information with the closest distance, the pixel numbering is used to implement a search method from near to far, which can effectively reduce the amount of calculation and improve calculation efficiency.

[0025] The present application also provides a bulletproof helmet detection device for implementing the above detection method, comprising a support assembly and a measurement assembly. The support assembly comprises a support body, the support body is provided with a first cavity, and the measurement assembly is accommodated in the first cavity. The measurement assembly comprises a laser light source, a beam expander lens, a beam splitter grating and an image sensor, the beam expander lens is used to diffuse the laser emitted by the laser light source, the beam splitter grating is used to divide the diffused laser into laser dot arrays, and the image sensor is used to record the position information of the laser dot array.

[0026] Technical effects and advantages of the present invention: 1. This application obtains the real-time displacement vector of the laser dot matrix by irradiating the inner surface of the helmet to be tested with a laser dot matrix and measuring the initial position information and real-time position information of each laser point in the laser dot matrix, which can then be used to determine the deformation of the helmet to be tested; 2. Considering that the helmet to be tested may undergo rigid displacement during the test, the component with the smallest absolute value is selected in the real-time displacement vector, and this component is subtracted from each component in the real-time displacement vector to obtain the real displacement vector of the laser dot matrix, thereby filtering out the influence of the rigid displacement of the helmet to be tested on the actual deformation and improving the measurement accuracy; 3. The laser ranging technology is used to measure the deformation of the helmet to be tested, which has fast response speed and high precision. At the same time, the laser and image sensor are very small and can be easily arranged in the bracket assembly, so that the deformation of the helmet to be tested can be measured from inside the bracket assembly, which improves the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flow chart of the detection method provided in Example 1 of the present invention.

[0028] Figure 2 Schematic diagram of a method for calculating the position information of a laser point in Embodiment 1 of the present invention.

[0029] Figure 3 Schematic diagram of a method for calculating the position information of laser points in the second embodiment of the present invention.

[0030] Figure 4 This is a cross-sectional view of the detection device provided in Embodiment 3 of the present invention.

[0031] The reference numerals in the drawings are: 1, support assembly; 11, bracket body; 12, first cavity; 2, measurement assembly; 21, laser light source; 22, beam expander lens; 23, spectroscopic grating; 24, image sensor; 241, photosensitive element; 242, objective lens; 100, helmet to be tested. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1 refer to Figure 1 and Figure 2 , Embodiment 1 of the present invention provides a method for detecting a bulletproof helmet, comprising the following steps: S1, using a laser light source 21 to form a laser dot matrix on the inner surface of the helmet 100 to be tested; S2. Obtaining the initial position information of each laser point in the laser dot matrix reflected by the helmet 100 to be tested , forming the initial position vector ; S3, periodically obtain the real-time position information of each laser point in the laser dot matrix reflected by the helmet 100 to be tested , forming the real-time position vector ; S4, according to the initial position vector and the real-time position vector at adjacent moments Calculate the real-time displacement vector of the laser dot matrix ; S5. From real-time displacement vector Filter out the component with the smallest absolute value from all the components; S6. Real-time displacement vector Subtract the component with the smallest absolute value from each component to obtain the true displacement vector of the laser dot array.

[0034] The present application obtains the real-time displacement vector of the laser dot matrix by irradiating the inner surface of the helmet 100 to be tested, and measuring the initial position information and real-time position information of each laser point in the laser dot matrix, which can then be used to determine the deformation of the helmet 100 to be tested. At the same time, considering that the helmet 100 to be tested may undergo rigid displacement during the test, the component with the smallest absolute value is screened out in the real-time displacement vector, and this component is subtracted from each component in the real-time displacement vector to obtain the real displacement vector of the laser dot matrix, thereby filtering out the influence of the rigid displacement of the helmet 100 to be tested on the actual deformation, and improving the measurement accuracy.

[0035] Specifically, the initial position information is obtained by the image sensor 24, which includes a photosensitive element 241 and an objective lens 242; The initial position information is obtained through the following steps: S11, obtaining the projection coordinates of the light reflected by each laser point on the photosensitive element 241; S12, calculating and obtaining the initial position information of each laser point according to the projection coordinates, the relative position between the photosensitive element 241 and the laser, and the relative position between the objective lens 242 and the photosensitive element 241.

[0036] The use of triangulation distance measurement is to calculate the distance by using the geometric relationship between the reflected light and the receiver. It has the characteristics of fast response speed and high precision, and is suitable for the rapid measurement of dynamic targets. There are two ways to implement triangulation distance measurement. One is the direct type, that is, the laser beam vertically illuminates the inner surface of the helmet 100 to be tested, which is convenient for arranging the laser light source 21 and the image sensor 24 to detect the center of the light spot, thereby improving the detection accuracy. The other is the oblique type, in which the laser beam illuminates the inner surface of the helmet 100 to be tested at a certain angle, which has a higher resolution.

[0037] In this embodiment, a specific implementation process of the direct-beam ranging method is given. Specifically, Figure 2 As shown, in step S12, the initial position information of each laser point is Calculated by the following formula:

[0038] In the formula, is the distance between the projection of the laser point on the photosensitive element 241 and the objective lens 242 in the first direction x, is the distance between the photosensitive element 241 and the objective lens 242 in the second direction y, is the distance between the projection of the laser point on the photosensitive element 241 and the laser light source 21 in the first direction x, is the distance between the laser light source 21 and the photosensitive element 241 in the second direction y, is the angle between the laser point position and the optical axis of the laser light source 21 .

[0039] Furthermore, in step S3, the real-time position information of each laser point Obtained by the following formula:

[0040] In the formula, is the displacement of the projection of the laser point on the photosensitive element 241 at time t.

[0041] Specifically, a common way to calculate the real-time displacement vector is as follows:

[0042] Where the initial position vector is: ; The real-time position vector is: ; Each component in the real-time displacement vector is: .

[0043] Since the position of the laser point reflected on the image sensor 24 is different each time it is collected, it is necessary to match the position of the laser point collected each time one by one. Considering that the deformation process of the helmet 100 to be tested is continuously changing, when the image sensor 24 collects the position of the laser point at two adjacent time points, the position change of the laser point is small. Therefore, the coordinate information with the closest distance can be found in the real-time coordinate data set obtained at two adjacent moments. This coordinate information is the coordinate information after the change of this laser point.

[0044] Specifically, the displacement of the projection of the laser point on the photosensitive element 241 is Obtain it by following these steps: S21. Number each laser point and record The initial coordinate information of each laser point at the moment forms the initial coordinate data set of the laser dot array ; S22. Periodic Recording The coordinate information of the projection of each laser point on the photosensitive element 241 at the moment forms a real-time coordinate data set ; S23, for each laser point, Find the real-time coordinate data set at the time The coordinate information at the moment is the closest to the coordinate information, that is, the laser point is at The coordinates at the moment, thus forming a real-time coordinate data set of the laser dot matrix ; S24, each laser point is located at The coordinates of the moment are the same as the laser point The distance of the coordinates at the time is the distance of the laser point at The displacement of the projection on the photosensitive element 241 at the moment .

[0045] When searching for the closest coordinate information, a traversal method can be used to search for the closest coordinate information, but this method requires a large amount of calculation, which will inevitably affect the calculation speed for an image sensor 24 with a large number of pixels. Therefore, this embodiment uses the pixel numbering to implement a near-to-far search method.

[0046] For example, use the following steps to number each laser point: S31, numbering pixels of the photosensitive element 241 according to their row and column numbers; S32, in At a certain moment, when the projection of the laser point on the photosensitive element 241 falls on a certain pixel, the number of the pixel is used as the number of the laser point.

[0047] A point on the coordinate system of the photosensitive element 241 substantially corresponds to a pixel, so such a numbering method is used to conveniently correspond the number of each laser point with its initial position information.

[0048] In step S23, the steps of finding the nearest coordinate information are as follows: S41, in At a certain moment, when the projection of the laser point on the photosensitive element 241 falls on a certain pixel, the number of the pixel is recorded; S42, in Real-time coordinate data set at the moment In the real-time coordinate data set, the pixel number is used as the starting point, and the adjacent numbers are searched one by one from near to far until the pixel number is found. The number that exists in The coordinate information of the laser point at this moment is recorded as the laser point corresponding to this number at Coordinate information at the time.

[0049] For example, in The real-time coordinate data set obtained at the moment is , where n contains the numbers of all laser points. Real-time coordinate data set obtained at all times In the example above, we need to find a certain coordinate information. When the corresponding laser point position is numbered, the corresponding pixel number is first obtained according to the coordinate information. For example, a photosensitive element 241 has n rows and m columns of pixels, and the coordinate information The corresponding pixel is the pixel in the i-th row and j-th column, so the number of this pixel is nimj. The numbers of the pixels adjacent to this pixel are n(i-1)mj, n(i+1)mj, nim(j-1), nim(j+1), n(i-1)m(j-1), n(i-1)m(j+1), n(i+1)m(j-1), n(i+1)m(j+1), a total of eight pixels. Real-time coordinate data set obtained at all times Find out whether there is a number that matches these eight pixel numbers. If so, assume that the number n(i+1)m(j-1) exists in the real-time coordinate data set. In the The laser point corresponding to this number is Coordinate information at the moment, coordinate information and Coordinate information at the time The distance between them is the laser point numbered n(i+1)m(j-1) Displacement of time .

[0050] This method is used to find the coordinate information with the closest distance. There is no need to calculate the distances of all coordinate points. Only a simple comparison of the numbers is required, which effectively reduces the amount of calculation and improves calculation efficiency.

[0051] Embodiment 2 In the second embodiment, the oblique illumination triangulation method is used for distance measurement, such as Figure 3 As shown, the laser beam irradiates the inner surface of the helmet 100 to be tested at a certain angle. Specifically, the initial position information of each laser point is Calculated by the following formula:

[0052] In the formula, is the angle between the laser light source 21 irradiating the laser point and the plane where the photosensitive element 241 is located, and the meanings of other symbols are the same as those in the first embodiment.

[0053] Real-time position information of each laser point Obtained by the following formula:

[0054] In the formula, is the displacement of the projection of the laser point on the photosensitive element 241 at time t.

[0055] This calculation method is consistent with the basic principle of the direct calculation method. Both methods calculate the position information of the laser point through geometric relationships, so specific data is no longer used for calculation.

[0056] In the actual detection process, since the inner surface of the helmet 100 to be tested is an irregular arc surface, the laser emitted by the laser light source 21 is difficult to be perpendicular to the surface it irradiates. Therefore, this method is often used for calculation in actual detection to facilitate a more flexible arrangement of the laser light source 21 and the image sensor 24.

[0057] Embodiment 3 The present application also provides a bulletproof helmet detection device for implementing the above detection method, such as Figure 4 As shown, it includes a measuring component 2 and a supporting component 1. The supporting component 1 includes a supporting body 11, the supporting body 11 is provided with a first cavity 12, and the measuring component 2 is accommodated in the first cavity 12. The measuring component 2 includes a laser light source 21, a beam expanding lens 22, a beam splitting grating 23 and an image sensor 24, the beam expanding lens 22 is used to diffuse the laser emitted by the laser light source 21, the beam splitting grating 23 is used to divide the diffused laser into laser dot arrays, and the image sensor 24 is used to record the position information of the laser dot array.

[0058] There are many options for the photosensitive element 241 in the image sensor 24. Commonly used ones include CMOS chips and CCD chips. CMOS chips are preferred because each pixel of the CMOS chip integrates an independent amplification circuit, has a fast response speed, and is suitable for high-speed sampling.

[0059] Since the bullet flies at a high speed, the time it takes to hit the helmet is very short, so a means of quickly measuring deformation is needed, and the laser ranging technology has the characteristics of fast response speed and high precision, which can achieve high-speed and accurate measurement of regional deformation. At the same time, the laser light source 21 and the image sensor 24 are very small in size, and are conveniently arranged in a small space such as the first cavity 12.

[0060] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting a bulletproof helmet, characterized in that: The following steps are involved: S1. Use a laser light source to form a laser dot matrix on the inner surface of the helmet to be tested; S2. Obtaining the initial position information of each laser point in the laser dot matrix reflected by the helmet to be tested , forming the initial position vector ; S3, periodically obtain the real-time position information of each laser point in the laser dot matrix reflected by the helmet to be tested , forming the real-time position vector ; S4, according to the initial position vector and the real-time position vector at adjacent moments Calculate the real-time displacement vector of the laser dot array ; S5. From the real-time displacement vector Filter out the component with the smallest absolute value from all the components; S6, the real-time displacement vector By subtracting the component with the smallest absolute value from each component in , the real displacement vector of the laser dot array can be obtained.

2. The method for detecting a bulletproof helmet according to claim 1, characterized in that: The initial position information is obtained by an image sensor, and the image sensor includes a photosensitive element and an objective lens; The initial position information is obtained by the following steps: S11, obtaining the projection coordinates of the light reflected by each laser point on the photosensitive element; S12, calculating and obtaining the initial position information of each of the laser points according to the projection coordinates, the relative position of the photosensitive element and the laser light source, and the relative position of the objective lens and the photosensitive element.

3. The method for detecting a bulletproof helmet according to claim 2, characterized in that: In step S12, the initial position information of each laser point is Calculated by the following formula: ， In the formula, is the distance between the projection of the laser point on the photosensitive element and the objective lens in the first direction, is the distance between the photosensitive element and the objective lens in the second direction, is the distance between the projection of the laser point on the photosensitive element and the laser light source in the first direction, is the distance between the laser light source and the photosensitive element in the second direction, is the angle between the laser point and the optical axis of the laser light source, and the first direction is perpendicular to the second direction.

4. The method for detecting a bulletproof helmet according to claim 3, characterized in that: In step S3, the real-time position information of each laser point Obtained by the following formula: ， In the formula, is the displacement of the projection of the laser point on the photosensitive element at time t.

5. The method for detecting a bulletproof helmet according to claim 2, characterized in that: In step S12, the initial position information of each laser point is Calculated by the following formula: ， In the formula, is the distance between the projection of the laser point on the photosensitive element and the objective lens in the first direction, is the distance between the photosensitive element and the objective lens in the second direction, is the distance between the projection of the laser point on the photosensitive element and the laser light source in the first direction, is the distance between the laser light source and the photosensitive element in the second direction, It is the angle between the laser light source irradiating the laser point and the plane where the photosensitive element is located, and the first direction is perpendicular to the second direction.

6. The method for detecting a bulletproof helmet according to claim 5, characterized in that: In step S3, the real-time position information of each laser point Obtained by the following formula: ， In the formula, is the displacement of the projection of the laser point on the photosensitive element at time t.

7. The method for detecting a bulletproof helmet according to claim 6, characterized in that: The displacement of the projection of the laser point on the photosensitive element Obtain it by following these steps: S21, number each laser point and record The initial coordinate information of each laser point at the moment forms the initial coordinate data set of the laser dot array ; S22. Periodic Recording The coordinate information of the projection of each laser point on the photosensitive element at the moment forms a real-time coordinate data set ; S23, for each of the laser points, Find the real-time coordinate data set at the time The coordinate information at the moment is the closest to the coordinate information, that is, the laser point is at The coordinates at the moment, thereby forming a real-time coordinate data set of the laser dot array ; S24, each of the laser points is located at The coordinates of the time are the same as the laser point The distance of the coordinates at the time is the distance of the laser point at The displacement of the projection on the photosensitive element at the moment .

8. The method for detecting a bulletproof helmet according to claim 7, characterized in that: The steps for numbering each of the laser points are as follows: S31, numbering pixels of the photosensitive element according to their row and column numbers; S32, in At a certain moment, when the projection of the laser point on the photosensitive element falls on a certain pixel, the number of the pixel is used as the number of the laser point.

9. The method for detecting a bulletproof helmet according to claim 8, characterized in that: In step S23, the steps of finding the nearest coordinate information are as follows: S41, in At a certain moment, when the projection of the laser point on the photosensitive element falls on a certain pixel, the number of the pixel is recorded; S42, in Real-time coordinate data set at the moment In the example, starting from the pixel number, the adjacent numbers are searched one by one from near to far until the pixel in the real-time coordinate data set is found. The number that exists in The coordinate information of the laser point at the time is recorded as the laser point corresponding to this number at Coordinate information at the time.

10. A bulletproof helmet detection device, used to implement the detection method according to claim 1, characterized in that: It includes a supporting component and a measuring component; The support assembly comprises a support body, the support body is provided with a first cavity, and the measuring assembly is accommodated in the first cavity; The measuring component includes a laser light source, a beam expanding lens, a beam splitter grating and an image sensor. The beam expanding lens is used to diffuse the laser light emitted by the laser light source, the beam splitter grating is used to divide the diffused laser light into laser dot arrays, and the image sensor is used to record the position information of the laser dot array.

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