A device and method for three-dimensional imaging of electromagnetic orbital deposition layer composition and hardness detection

Abstract

This application discloses a device and method for three-dimensional imaging of the composition and hardness of electromagnetic orbital deposits, including a detection host and a detection probe. The detection host triggers the laser and performs optical tomography (LIBS) data analysis outside the electromagnetic orbital chamber. It is equipped with a scanning path control system to achieve two-dimensional planar scanning of the deposited layer on the electromagnetic orbital surface. An automatic focusing control system not only scans the depth direction of the deposited layer on the electromagnetic orbital surface but also detects and corrects the levelness of the pulsed laser output end face of the detection probe relative to the area near the current scanning point on the electromagnetic orbital deposited layer surface, and automatically focuses the fiber optic output lens group in the detection probe relative to the bottom of the ablation pit at the current scanning point. Under the control of the detection host, the detection probe enters the electromagnetic orbital chamber to acquire optical tomography (LIBS) data in real time, in situ, non-destructively, and rapidly.

Description

Technical Field

[0001] This application belongs to the field of electromagnetic launch technology and relates to a device and method for three-dimensional imaging of the composition and hardness of electromagnetic orbital deposition layers. Background Technology

[0002] Electromagnetic orbital launch is a novel launch technology that uses electromagnetic energy to propel objects to high or ultra-high speeds. Compared with traditional chemical energy launch, electromagnetic orbital launch can break through the theoretical speed limit of traditional chemical launch methods and has significant advantages such as high launch speed, high launch energy, high launch frequency, and strong continuous launch capability. It has important application prospects in the military field.

[0003] During electromagnetic launch, megaampere-level currents are typically injected into the track to generate time-varying magnetic fields of several Tesla, accelerating the armature and enabling launch. During this process, the temperature rise within the launch cavity is drastic due to Joule heating from the high current, frictional heat from high-speed current carrying, and contact resistance heat. This causes armature material to migrate to the track surface, forming deposits that alter the track's electrical, thermal, and mechanical properties, shortening its lifespan and ultimately leading to failure. Therefore, timely detection of the residual element distribution and mechanical properties in the track surface deposit layer is crucial. However, current methods for detecting electromagnetic launch track deposits mostly rely on offline measurements using laboratory samples. These methods have strict requirements on sample size, often requiring cutting, grinding, and polishing, which can cause permanent damage to the track, preventing repeated launches. Furthermore, these methods are time-consuming, only detect shallow surface components, and cannot provide a complete assessment of the entire track surface deposit layer. Therefore, designing and developing a device and analytical method that eliminates the need for sample cutting, allows for in-situ measurement of the three-dimensional distribution of electromagnetic launch track deposit components, and enables in-situ measurement of hardness and mechanical properties within the electromagnetic launch chamber. Summary of the Invention

[0004] The purpose of this application is to solve the problems of existing electromagnetic launch orbit deposition layer detection, which requires cutting and sending samples, can only detect the shallow surface composition distribution, and cannot fully evaluate the deposition layer on the entire orbit surface. The application provides a device and method for three-dimensional imaging of electromagnetic orbit deposition layer composition and hardness detection.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] In a first aspect, this application provides a three-dimensional imaging and hardness testing device for electromagnetic orbital deposition layer composition, comprising:

[0007] The detection host includes a control unit connected to the control terminal of a laser. The laser output is equipped with an optical fiber input lens group, which is connected to the input terminal of a spectrometer. The optical fiber input lens group is connected to the detection probe via a transmission optical fiber. The data output terminal of the spectrometer is connected to an analysis unit, which is used to analyze the three-dimensional imaging and hardness distribution of the electromagnetic emission orbit deposition layer composition within the current scanning area.

[0008] The detection probe includes a probe attitude control module, which is connected to the control unit of the detection host via a signal control line. The control end of the probe attitude control module is connected to the fiber optic output lens group and the camera, and is used to transmit the plasma light generated under pulsed laser irradiation back to the fiber optic input lens group through the transmission fiber.

[0009] Furthermore, the control unit of this application includes a scanning path control system, an autofocus control system, and a timing control system; the scanning path control system is connected to the probe attitude control module via a first signal control line; the autofocus control system is connected to the probe attitude control module via a second signal control line; and the timing control system is connected to the laser and the spectrometer respectively.

[0010] Furthermore, the analysis unit of this application includes a composition analysis system and a hardness analysis system, the input terminals of which are both connected to the output terminal of the spectrometer.

[0011] Furthermore, the probe attitude control module of this application includes a drive motor, an angular displacement sensor, a linear displacement sensor, and an image transmission converter;

[0012] The drive motor is used to move the detection probe.

[0013] The angle displacement sensor is used to acquire the swing angle θ of the fiber optic output lens group;

[0014] The linear displacement sensor is used to acquire the position p of the fiber optic output lens group;

[0015] The image transmission converter is used to sample, quantize, and encode the analog video signal captured by the camera to obtain a smaller digital signal.

[0016] Secondly, this application provides a method for three-dimensional imaging of the composition and hardness detection of electromagnetic orbital deposition layers, comprising the following steps:

[0017] Step 1: The scanning path control system sets the coordinates (x0, y0) of the scanning starting point according to the input scanning path, and controls the probe attitude control module to move the detection probe B to the scanning starting point via the signal control line; the probe attitude control module transmits the swing angle θ of the fiber optic output lens group back to the autofocus control system via the second signal control line; the probe attitude control module transmits the position p of the fiber optic output lens group back to the autofocus control system via the second signal control line; the probe attitude control module controls the camera to transmit the current field of view image S back to the autofocus control system 2 via the second signal control line; the probe attitude control module 9 transmits the current scanning starting point coordinates (x0, y0) back to the scanning path control system via the first signal control line.

[0018] Step 2: The scanning path control system in the detection host controls the drive motor in the probe attitude control module of the detection probe according to the input scanning path, causing the detection probe to perform a two-dimensional trajectory scan on the surface of the electromagnetic emission track deposition layer; the autofocus control system in the detection host controls the angular movement and stepping direction of the drive motor in the probe attitude control module to achieve focusing and horizontal detection of the detection probe, causing the detection probe to perform depth-direction scanning detection on the surface of the electromagnetic emission track deposition layer; the autofocus control system, according to the input single-point trigger pulse number N... spot By controlling the number of pulse triggers of the laser at a single point on the surface of the deposited layer, the length in the depth direction can be controlled.

[0019] Step 3: The laser is fed into the detection probe and refocused through the fiber optic output lens group, finally irradiating the current scanning point to generate plasma and its radiated light; when the number of trigger pulses reaches N... spot Then, the autofocus control system inputs an autofocus completion command to the probe attitude control module;

[0020] Step 4: The detection probe passes through N to each scanning point within the entire scanning area. spot N generated under subpulse laser irradiation spot The secondary plasma radiation light is focused by the fiber optic output lens group and enters the transmission fiber, which is then transmitted back to the detection host in real time.

[0021] Step 5: The plasma radiation light transmitted back to the detection host is focused again into the spectrometer through the fiber optic input lens group. The spectrometer expands the intensity of the plasma radiation light at each wavelength image point to obtain the LIBS spectrum of optical tomography.

[0022] Step 6: Input the optical tomography (LIBS) spectrum into the component analysis system and hardness analysis system for processing to obtain the actual content (c) of all components to be analyzed in the current scanning area under each laser pulse. *The system outputs the three-dimensional imaging and hardness distribution results of the electromagnetic emission orbit deposition layer composition within the current scanning area, along with the hardness Hv of all scanned points.

[0023] Furthermore, the scanning path of this application includes scanning rate v0, scanning space x-axis resolution dx, x-axis scanning point number m, scanning space y-axis resolution dy, and y-axis scanning point number n.

[0024] Furthermore, before triggering the laser, the automatic focusing control system of this application first performs horizontal detection and automatic focusing based on the current field-of-view image S, the swing angle θ and position p of the fiber optic output lens group transmitted back by the probe attitude control module; then it inputs a trigger pulse to the laser; after receiving the trigger pulse signal, the laser outputs a pulsed laser that enters the fiber optic input lens group for focusing, and after focusing, it is fed into the transmission fiber, and after transmission through the transmission fiber, it enters the detection probe.

[0025] Compared with the prior art, this application has the following beneficial effects:

[0026] This application enables three-dimensional imaging and hardness testing of residual elements in the intact track deposit layer without cutting, within the electromagnetic launch track chamber. The designed device consists of two parts: a detection host and a detection probe. 1) The detection host triggers the laser and performs optical tomography (LIBS) data analysis outside the electromagnetic launch track chamber. It also includes a scanning path control system for two-dimensional planar scanning of the deposit layer on the electromagnetic launch track surface; and an automatic focusing control system that not only scans the depth direction of the deposit layer but also detects and corrects the levelness of the pulsed laser output end face of the detection probe relative to the area near the current scanning point on the electromagnetic launch track deposit layer surface, and automatically focuses the fiber optic output lens group in the detection probe relative to the bottom of the ablation pit at the current scanning point. 2) Under the control of the detection host, the detection probe enters the electromagnetic launch track chamber to acquire optical tomography (LIBS) data in real time, in situ, non-destructively, and rapidly. This application effectively solves the problems of existing electromagnetic launch track deposit layer composition and hardness testing technologies, such as damage to track integrity, long testing cycles, and inability to perform in-situ testing, providing a new method for reliability and lifespan assessment of electromagnetic launch devices. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1This is a structural diagram of the electromagnetic orbital deposition layer composition three-dimensional imaging and hardness detection device based on optical tomography (LIBS) of this application.

[0029] Figure 2 This is a structural design diagram of the probe attitude control module in the device of this application.

[0030] Figure 3 This is a flowchart of the method for three-dimensional imaging of electromagnetic orbital deposition layer composition and hardness detection based on optical tomography (LIBS) of this application.

[0031] Figure 4 This is a flowchart illustrating the functionality of the scanning path control system described in this application.

[0032] Figure 5 This is a flowchart illustrating the functionality of the autofocus control system of this application.

[0033] Figure 6 A flowchart illustrating the functionality of the component analysis system of this application.

[0034] Figure 7 This is a flowchart illustrating the functionality of the hardness analysis system described in this application.

[0035] Figure 8 The field-of-view image of the current scanning point is obtained by accumulating 100 pulsed lasers for the electromagnetic launch track copper material provided in the embodiments of this application.

[0036] Figure 9 The spectrum was measured after accumulating 100 pulsed lasers for the electromagnetic launch orbital copper material provided in the embodiments of this application.

[0037] Wherein: A-Detection host, B-Detection probe, 1-Scanning path control system, 2-Autofocus control system, 3-Timing control system, 4-Laser, 5-Spectrometer, 6-Fiber optic input lens group, 7-Component analysis system, 8-Hardness analysis system, 9-Probe attitude control module, 91-Drive motor, 92-Angle displacement sensor, 93-Linear displacement sensor, 94-Image transmission converter, 10-Fiber optic output lens group, 11-Camera, 12-Transmission fiber optic cable, 13-First signal control line, 14-Second signal control line. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of the embodiments of this application, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0043] In the description of the embodiments of this application, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] The present application will now be described in further detail with reference to the accompanying drawings:

[0045] See Figure 1This application discloses a three-dimensional imaging and hardness testing device for electromagnetic orbital deposition layers based on optical tomography (LIBS), comprising a detection host A and a detection probe B. The detection host A includes a scanning path control system 1, an autofocus control system 2, a timing control system 3, a laser 4, a spectrometer 5, an optical fiber input lens group 6, a composition analysis system 7, and a hardness analysis system 8. The detection probe B includes a probe attitude control module 9, an optical fiber output lens group 10, and a camera 11. The detection host A communicates with the detection probe B via first signal control lines 13 and 14. The detection host A transmits pulsed laser light to the detection probe B via transmission optical fiber 12 and simultaneously receives plasma radiation light from the detection probe B. Figure 2 As shown, the probe attitude control module 9 includes a drive motor 91, an angle displacement sensor 92, a linear displacement sensor 93, and an image transmission converter 94. The image transmission converter is used to sample, quantize, and encode the analog video signal captured by the camera to obtain a smaller digital signal, which facilitates higher transmission rates.

[0046] The detection host A performs optical tomography (LIBS) data analysis outside the electromagnetic launch track chamber and sends control commands to the detection probe B, which then enters the electromagnetic launch track chamber to collect LIBS data.

[0047] like Figure 4 As shown, the scanning path control system 1 defines the scanning area of ​​the electromagnetic launch orbit deposition layer based on the input scanning start point coordinates (x0, y0), scanning rate v0, x-axis scanning resolution dx, y-axis scanning resolution dy, number of x-axis scanning points m, and number of x-axis scanning points n. The discrete point set of the scanning area is set as follows:

[0048] {(x i ,y j )|x i =x0+(i-1)dx,y j =y0+(j-1)dy,i=1,2,…,m; j=1,2,…,n}

[0049] Next, the drive motor 91 in the probe attitude control module 9 is driven by the first signal control line 13. The drive motor 91 drives the detection probe B back to the scanning start point (x0, y0), and at the same time, according to the input single-point trigger pulse number N... spot Output the total number of trigger pulses N required for each scan point to laser 4. spotThen, it waits for the probe attitude control module 9 to input an autofocus completion command to the scanning path control system 1 via the first signal control line 13. Upon receiving the autofocus completion command, the scanning path control system 1 continues to drive the motor 91 to move the detection probe B along the direction of increasing x-axis i at a scanning rate of v0 to the next scanning point (x1, y0), and continues to wait for the probe attitude control module 9 to input the next autofocus completion command. Each time an autofocus completion command is received, i increases by a step of 1, driving the detection probe B to move to the next scanning point (x1, y0). i When i>m, let j=j+1, drive motor 91 to drive the detection probe B back to the starting point of the next row of the y-axis scan, i.e. (x0,y1). Then wait for the probe attitude control module 9 to input the next autofocus completion command, continue to scan along the direction of increasing x-axis i at a scanning rate of v0 to complete the x-axis scan, and then drive motor 91 to drive the detection probe B back to the starting point of the next row of the y-axis scan (x0,y2) until j>n to complete the scanning of all point sets in the scanning area, and finally output a pause command to laser 4.

[0050] like Figure 5 As shown, the autofocus control system 2 determines the number of single-point trigger pulses N based on the input current coordinates (x, y). spot The number of triggered pulses is set to i = 1. Then, the horizontality of the area near the current coordinates (x, y) of the electromagnetic emission track deposition layer surface near the pulsed laser output end face of the detection probe B is measured sequentially. The focus position of the fiber optic output lens group 10 in the detection probe B is automatically focused relative to the bottom position of the ablation pit at the current coordinates (x, y). After completing the horizontality and automatic focus measurements at the current coordinates (x, y), the automatic focus control system 2 outputs a trigger pulse to the laser 4. The laser 4 outputs a pulsed laser, which is focused by the fiber optic input lens group 6 and enters the transmission fiber 12. The transmission fiber 12 transmits the pulsed laser to the detection probe B, where it is refocused by the fiber optic output lens group 10 and then output from the laser output end face of the detection probe B, outputting a pulsed laser to the current coordinate point (x, y) on the electromagnetic emission track deposition layer surface. When i <N spot At this point, let i = i + 1, and continue to perform levelness detection and autofocus detection at the current coordinates (x, y). After completing the levelness detection and autofocus detection, control laser 4 to output a trigger pulse, and output a second pulse laser to the current coordinate point (x, y) on the surface of the electromagnetic emission orbit deposition layer. Continue to let i = i + 1, and repeat the above steps until i ≥ N. spot At that time, complete the N coordinates at the current coordinate point (x,y). spot The pulse is emitted, and finally the autofocus completion command is input to the probe attitude control module 9.

[0051] The levelness detection of the area near the current coordinates (x, y) of the pulsed laser output end face of the detection probe B and the surface of the electromagnetic emission orbit deposition layer is performed as follows: First, the autofocus control system 2 controls the detection probe B through the second signal control line 14. The probe attitude control module 9 in the detection probe B controls the camera 11 to capture the current field of view image S(θ1). The angle displacement sensor 92 in the probe attitude control module 9 measures the swing angle θ1 of the fiber optic output lens group 10. The S(θ1) and θ1 processed by the image transmission converter 94 are then transmitted back to the autofocus control system 2 through the second signal control line 14. In the autofocus control system 2, the background grayscale matrix f(θ1) is calculated from the transmitted current field of view image S(θ1), and the average background grayscale value f is calculated based on the background grayscale matrix f(θ1). bg (θ1), matrix dimension M1 rows and N1 columns; then calculate the leveling function value under the current swing angle:

[0052] F(θ1)=∑(f(θ1)-f bg (θ1)) 2 / (M1×N1)

[0053] Next, the autofocus control system 2 controls the drive motor 91 in the probe attitude control module 9 to swing forward by dθ via the second signal control line 14. The angle displacement sensor 92 in the probe attitude control module 9 measures the current swing angle θ2 = θ1 + dθ of the fiber optic output lens group 10. The camera 11 captures the current field of view image S(θ2). The image transmission converter 94 processes S(θ2). Then, the probe attitude control module 9 transmits the processed S(θ2) and θ2 back to the autofocus control system 2 via the second signal control line 14. In the autofocus control system 2, the background grayscale matrix f(θ2) is obtained from the transmitted current field of view image S(θ2). The average background grayscale value f is calculated based on the background grayscale matrix f(θ2). bg (θ2), matrix dimension M2 rows and N2 columns, calculate the leveling function value under the current swing angle θ2:

[0054] F(θ2)=∑(f(θ2)-f bg (θ2)) 2 / (M2×N2)

[0055] When F(θ1) < F(θ2), the autofocus control system 2 sends an instruction in the reverse swing direction to the drive motor 91 in the probe attitude control module 9. The drive motor 91 drives the detection probe B to swing in the reverse direction. When F(θ1) ≥ F(θ2), let F(θ1) = F(θ2) and θ1 = θ2. The autofocus control system 2 controls the drive motor 91 in the probe attitude control module 9 to continue to swing forward by dθ through the second signal control line 14. The angle displacement sensor 92 in the probe attitude control module 9 measures the current swing angle θ2 of the fiber optic output lens group 10. ′ = θ2 + dθ, and the camera 11 captures the current field of view image S(θ2 ′ ). The image transmission converter 94 then processes S(θ2 ′ ), and then the probe attitude control module 9 transmits S(θ2 ′ ) and θ2 ′ back to the autofocus control system 2 through the second signal control line 14; in the autofocus control system 2, the background gray matrix f(θ2 ′ ) is obtained from the back-transmitted current field of view image S(θ2 ′ ). According to the background gray matrix f(θ2 ′ ), the background gray average value f bg (θ2 ′ ) is calculated. The matrix dimension is M2 ′ rows and N2 ′ columns. Calculate the leveling function value at the current swing angle θ2 ′ :

[0056] F(θ2 ′ ) = ∑(f(θ2 ′ ) - f bg (θ2 ′ )) 2 / (M2 ′ × N2 ′ )

[0057] When F(θ2 ′ ) < F(θ1), let F(θ2) = F(θ2 ′ ), θ2 = θ2 ′ . Then let F(θ1) = F(θ2) and θ1 = θ2. The drive motor 91 drives the detection probe B to continue to swing forward by dθ, and recalculate the leveling function value F(θ2 ′ ) at the current swing angle θ2 ′ ) until F(θ2 ′ ) ≥ F(θ1). At this time, the swing angle θ1 of the fiber optic output lens group 10 is considered the optimal focusing swing angle. At this time, the flatness of the area near the current coordinates (x, y) of the pulsed laser output end face of the detection probe B and the surface of the electromagnetic emission track deposition layer is the best, and the flatness detection is completed.

[0058] The autofocus system detects the focus position of the fiber optic output lens group 10 in probe B and the position of the bottom of the ablation pit at the current coordinates (x, y). After completing the levelness detection and obtaining the optimal focus angle θ1, the autofocus control system 2 controls probe B through the second signal control line 14. The probe attitude control module 9 in probe B controls the camera 11 to capture the current field of view image S(p1). The linear displacement sensor 93 in the probe attitude control module 9 measures the position p1 of the fiber optic output lens group 10. The processed images S(p1) and p1, after being processed by the image transmission converter 94, are transmitted back to the autofocus control system 2 through the second signal control line 14. In the autofocus control system 2, the average background grayscale g is calculated from the transmitted current field of view image S(p1). bg (p1), the maximum grayscale value of the current field of view, g max (p1); Next, calculate the focus function value at the current position p1:

[0059] G(p1)=(g max (p1)-g bg (p1)) / g bg (p1)×100%

[0060] Next, the autofocus control system 2 controls the drive motor 91 in the probe attitude control module 9 to step forward by dz via the second signal control line 14. The linear displacement sensor 93 in the probe attitude control module 9 measures the current position p2 = p1 + dz of the fiber optic output lens group 10. The camera 11 captures the current field of view image S(p2). The image transmission converter 94 processes S(p2). Then, the probe attitude control module 9 sends the processed S(p2) and p2 back to the autofocus control system 2 via the second signal control line 14. In the autofocus control system 2, the average background grayscale g is obtained from the returned current field of view image S(p2). bg (p2) and the current maximum gray level g in the field of view max (p2), calculate the focus function value at the current position p2:

[0061] G(p2)=(g max (p2)-g bg (p2)) / g bg (p2)×100%

[0062] When G(p2) < G(p1), the autofocus control system 2 sends an instruction to reverse the stepping direction to the drive motor 91 in the probe attitude control module 9. The drive motor 91 drives the detection probe B to reverse the stepping direction. When G(p2) ≥ G(p1), let G(p1) = G(p2) and p1 = p2. The autofocus control system 2 controls the drive motor 91 in the probe attitude control module 9 to continue stepping forward by dz through the second signal control line 14. The linear displacement sensor 93 in the probe attitude control module 9 measures the current position p of the fiber optic output lens group 10. ′ 2 = p2 + dz, and the camera 11 captures the current field of view image S(p ′ 2). The image transmission converter 94 then processes S(p ′ 2), and then the probe attitude control module 9 transmits S(p ′ 2) and p ′ 2 back to the autofocus control system 2 through the second signal control line 14; in the autofocus control system 2, the background gray average value g ′ (p bg 2) and the maximum value g ′ (p max (p ′ 2) of the current field of view image gray scale are obtained, and the focus function value at the current position p ′ 2 of the fiber optic output lens group 10 is continuously calculated as follows:

[0063] G(p ′ 2) = (9g max (p ′ 2) - g bg (p ′ 2)) / g bg (p ′ 2) × 100%

[0064] When G(p1) < G(p ′ 2), let G(p2) = G(p ′ 2) and p2 = p ′ 2. Then let G(p1) = G(p2) and p1 = p2. The drive motor 91 drives the detection probe B to continue stepping forward by dz, and recalculates the focus function value G(p ′ 2) at the current position p of the fiber optic output lens group 10 at this time until G(p1) ≥ G(p ′ 2). At this time, it is considered that the position p1 of the fiber optic output lens group 10 is the optimal focus position. At this time, the focusing focus position of the fiber optic output lens group 10 in the detection probe B has the best focus degree with the position of the bottom of the ablation pit under the current coordinates (x, y), and the autofocus detection is completed.

[0065] ​​The autofocus control system 2 extracts the grayscale matrix from the field-of-view images captured and transmitted back by camera 11.

[0066] r g ={(r i ,r j )|i=1,2,…,M; j=1,2,…,N}

[0067] M is the grayscale matrix r g The number of rows, N is the grayscale matrix r g The number of columns; then, remove the background pixels with a length of 10% from the perimeter of the grayscale matrix to obtain a new grayscale matrix:

[0068]

[0069] Here, INT() is the floor function; then the new grayscale matrix is ​​processed. When performing wavelet thresholding denoising, the choice of the critical threshold is to ensure the new grayscale matrix... Edge row vector {(r i ,r j )|i=INT(0.1M),INT(0.9M);j=INT(0.1N),2,…,INT(0.9N)} and the marginal column vector {(r i ,r j The relative standard deviations of each of the following values ​​are less than 5%: i = INT(0.1M), 2, ..., INT(0.9M); j = INT(0.1N), INT(0.9N); Then, after wavelet threshold denoising, the new grayscale matrix... Based on this, data such as the average grayscale value of the background and the maximum grayscale value of the current field of view are extracted for subsequent levelness detection and autofocus processing.

[0070] In the autofocus control system 2, the drive motor 91 swings forward by dθ during level detection and steps forward by dz during autofocus. The "forward" direction is along the direction perpendicular to the electromagnetic emission track deposition layer and close to the current scanning point of the deposition layer. The swing angle dθ is the angle between the laser output end face of the detection probe B and the plane near the current scanning point, and the step distance dz is the distance along the "forward" direction from the laser output end face of the detection probe B to the current scanning point.

[0071] like Figure 6 As shown, the component analysis system 7 processes the optical tomography LIBS spectrum obtained by the spectrometer 5 to obtain a three-dimensional image of the composition of the electromagnetic emission orbit deposition layer currently being scanned. First, the optical tomography LIBS spectral intensity I of the component to be analyzed i under the j-th laser pulse is input. i Next, retrieve the original LIBS calibration curve c of the component to be analyzed, stored in the component analysis system 7.i =H(I i For the total number of trigger pulses N spot Calculate the spectral loss function of component i under the j-th laser pulse:

[0072]

[0073] The actual optical tomography LIBS spectral calibration curve of the component i under the j-th laser pulse was calculated by combining the spectral loss function. Finally, the actual content of the component i to be analyzed under the j-th laser pulse is output.

[0074] The original LIBS calibration curve c of the component to be analyzed i stored in the component analysis system 7 i =H(I i The standard samples, derived from a series of pre-prepared concentration gradients of the analyte i, are used to measure the LIBS spectral intensity of the standard samples. Partial least squares regression analysis is employed to calculate the calibration curve of the concentration of the analyte i versus its LIBS spectral intensity. The spectral loss function of the analyte i within the component analysis system 7 is also used. Derived from a pre-designed series of total trigger pulses N spot For a series of standard samples with concentration gradients of the analyte i, the LIBS spectral intensity of the standard samples under each laser pulse irradiation is measured. Intensity decay curves of the LIBS spectral intensity of the standard samples at the same point with respect to the number of laser pulses are obtained. For a series of total trigger pulses N... spot Repeat the above intensity decay curves to obtain the analyte i under different concentration gradients and different total trigger pulse numbers N. spot A database of three-dimensional spectral loss functions showing the variation of LIBS spectral intensity with pulse number:

[0075] lossFunction(N spot ,j,I i ,c i )

[0076] For a total number of trigger pulses of N spot In the case of the j-th laser pulse, the spectral loss function of component i is... For the three-dimensional spectral loss function database I i3D =lossFunction(N) spot ,j,I i ,c i The total number of trigger pulses corresponding to ) is N spot The LIBS spectral intensity I in the plane of the j-th laser pulse and the component i i The Manhattan distance of the function curve is the closest curve.

[0077] like Figure 7 As shown, the hardness analysis system 8 processes the optical tomography LIBS spectrum obtained from the spectrometer 5 to obtain the hardness distribution of the electromagnetic emission orbital deposition layer in the current scanning area. First, the optical tomography LIBS spectrum I(x,y) at the current scanning point coordinates (x,y) is input; then, the ionic spectral intensity I of the hardness characteristic element i is calculated. II (i), Atomic spectral intensity I I (i) and plasma temperature T e (i); Then, for the a hardness feature elements, calculate the hardness calibration element matrix R:

[0078] R(i) = [I II (i),I I (i),T e [i], i = 1, 2, ..., a

[0079] Based on the hardness calibration element matrix R, the hardness calibration function Hv=Ψ(R) is calculated to obtain the hardness value Hv at the current scanning point coordinates (x,y). Finally, the hardness value Hv at the current coordinates (x,y) is output in the detection host A.

[0080] The number 'a' of hardness characteristic elements in the hardness analysis system 8 is determined by pre-preparing a series of standard samples with known hardness gradients and measuring the ionic spectral intensities (I) of w elements within the series of standard samples. IIw and atomic spectral intensity I Iw Measurement of plasma temperature T based on the Saha Boltzmann method ew The hardness pre-calibration element matrix R is formed. w :

[0081] R w (i)=[I IIw (i),I Iw (i),T ew [(i)], i = 1, 2, ..., w

[0082] Calculate the hardness and the matrix R for each element separately. w (i) correlation coefficient r w (i) The set of hardness characteristic elements is the correlation coefficient r w (i) is the set of elements corresponding to 0.8, where the number of hardness characteristic elements a is the correlation coefficient r. w (i) The number of elements > 0.8. The hardness calibration function Hv = Ψ(R) within the hardness analysis system is a hardness calibration element matrix R composed of a series of hardness gradients established based on partial least squares regression analysis and the corresponding a hardness feature elements: R(i) = [I II (i),I I(i),T e (i)], i=1,2,…,a is the scaling function.

[0083] like Figure 3 As shown, this application provides a method for three-dimensional imaging of the composition and hardness detection of electromagnetic orbital deposition layers based on optical tomography (LIBS), including the following steps:

[0084] 1) Power on the detection host A and detection probe B, and allow the device to warm up for 2 minutes;

[0085] 2) Input the scanning path (including the scanning start coordinates (x0, y0), scanning rate v0, scanning space x-axis resolution dx, number of x-axis scanning points m, scanning space y-axis resolution dy, number of y-axis scanning points n), and number of single-point trigger pulses N into the detection host A. spot The spectral acquisition signal (including the trigger time interval t of laser 4 and spectrometer 5) delay (integration time τ);

[0086] 3) The timing control system 3 in the detection host A sets the trigger time interval t between the laser 4 and the spectrometer 5 based on the input spectral acquisition information. delay and integration time τ;

[0087] 4) The scanning path control system 1 in the detection host A sets the scanning start point coordinates (x0, y0) according to the input scanning path, and controls the drive motor 91 of the probe posture control module 9 in the detection probe B through the first signal control line 13, driving the detection probe B to move to the scanning start point. The angle displacement sensor 92 in the probe posture control module 9 transmits the swing angle θ of the fiber optic output lens group 10 back to the autofocus control system 2 through the second signal control line 14. The linear displacement sensor 93 in the probe posture control module 9 transmits the position p of the fiber optic output lens group 10 back to the autofocus control system 2 through the second signal control line 14. The image transmission converter 94 in the probe posture control module 9 controls the camera 11 to transmit the current shooting field image S back to the autofocus control system 2 through the second signal control line 14. The probe posture control module 9 transmits the current scanning start point coordinates (x0, y0) back to the scanning path control system 1 through the first signal control line 13.

[0088] 5) The scanning path control system 1 in the detection host A, based on the input scanning path, controls the drive motor 91 in the probe attitude control module 9 of the detection probe B via the first signal control line 13, causing the detection probe B to perform a two-dimensional trajectory scan on the surface of the electromagnetic emission track deposition layer. The autofocus control system 2 in the detection host A, through the second signal control line 14, controls the angular movement and stepping direction of the drive motor 91 in the probe attitude control module 9 to achieve automatic focusing and horizontal detection of the detection probe B, causing the detection probe B to perform depth-direction scanning detection on the surface of the electromagnetic emission track deposition layer. The autofocus control system 2, based on the input single-point trigger pulse number N, spot The length in the depth direction can be controlled by controlling the number of pulse triggers of laser 4 at a single point on the surface of the deposition layer.

[0089] 6) Before triggering the laser 4, the autofocus control system 2 first performs horizontal detection and autofocus based on the current field-of-view image S, the swing angle θ, and the position p of the fiber optic output lens group 10, which are transmitted back from the probe attitude control module 9. After achieving these two functions, a trigger pulse is input to the laser 4. After receiving the trigger pulse signal, the laser 4 outputs a pulsed laser that enters the fiber optic input lens group 6 for focusing. After focusing, it is fed into the transmission fiber 12 and transmitted through the transmission fiber 12 to the detection probe B.

[0090] 7) The laser light fed into the detection probe B is refocused through the fiber optic output lens group 10 and finally irradiates the current scanning point, generating plasma and its radiated light. When the number of trigger pulses reaches N... spot Then, the autofocus control system 2 inputs the autofocus completion command to the probe attitude control module 9 through the second signal control line 14.

[0091] 8) Under the real-time monitoring of the scanning path control system 1 and the autofocus control system 2, the detection probe B passes through N... spot N generated under subpulse laser irradiation spot The secondary plasma radiation light is focused by the fiber optic output lens group 10 and enters the transmission fiber 12, and is transmitted back to the detection host A in real time through the transmission fiber 12.

[0092] 9) The plasma radiation light returned to the detection host A is focused again by the fiber optic input lens group 6 into the spectrometer 5. The spectrometer expands the intensity of the plasma radiation light at each wavelength image point to obtain the LIBS spectrum of optical tomography.

[0093] 10) The obtained optical tomography LIBS spectrum is then processed by the component analysis system 7 and the hardness analysis system 8 to obtain the actual content c of all components to be analyzed in the current scanning area under each laser pulse. * Hardness Hv at all scan points.

[0094] 11) The detection host A outputs the three-dimensional imaging and hardness distribution results of the electromagnetic emission orbit deposition layer composition in the current scanning area.

[0095] Example

[0096] Combination Figures 1-9 This paper describes the practical effects of applying this application to the detection of copper materials in electromagnetic launch orbits.

[0097] In this embodiment, a 10mJ nanosecond pulsed laser (DAWA-100, FWHM-10ns, 1064nm, repetition frequency 2Hz) is used to focus the electromagnetic emission track on copper material in an air atmosphere. The emission spectrum intensity is recorded using a spectrometer (LTB, Aryelle Butterfly) with a detectable wavelength range of 270–690nm, and a camera (Olympus, bx53m) is used to capture the field of view image at the current scanning point. Figure 8 The image shows the grayscale image of the current scanning point field of view after accumulating 100 pulsed lasers. The darker ring structures in the image are ablation pits caused by the focusing of the pulsed lasers, and the regular, continuous dark lines in the image are scratches after the copper target has been ground and polished. Figure 9 The image shows the spectrum unfolded after accumulating 100 pulsed lasers collected by the spectrometer. The characteristic spectral lines of copper are clearly visible: Cu I 324.754nm, Cu I 327.396nm, Cu I 427.511nm, Cu I 465.112nm, Cu I 510.554nm, Cu I 515.324nm, Cu I 521.820nm, Cu I 529.252nm, Cu I 578.213nm, etc. This confirms the effectiveness of the device and method presented in this application, and it can be used for in-situ measurement of the three-dimensional distribution of composition and hardness of electromagnetic orbital deposition layers.

[0098] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A device for three-dimensional imaging of the composition and hardness detection of electromagnetic orbital deposition layers, characterized in that, include: The detection host (A) includes a control unit connected to the control terminal of the laser (4). The output of the laser (4) is set with an optical fiber input lens group (6), which is connected to the input terminal of the spectrometer (5). The optical fiber input lens group (6) is connected to the detection probe (B) through a transmission optical fiber (12). The data output terminal of the spectrometer (5) is connected to an analysis unit, which is used to analyze the three-dimensional imaging and hardness distribution of the electromagnetic emission orbit deposition layer composition in the current scanning area. The detection probe (B) includes a probe attitude control module (9). The probe attitude control module (9) is connected to the control unit of the detection host (A) via a signal control line. The control end of the probe attitude control module (9) is connected to the fiber optic output lens group (10) and the camera (11) to transmit the plasma light generated under pulsed laser irradiation back to the fiber optic input lens group (6) via the transmission fiber (12). The control unit includes a scanning path control system (1), an autofocus control system (2), and a timing control system (3); the scanning path control system (1) is connected to the probe posture control module (9) via a first signal control line (13); the autofocus control system (2) is connected to the probe posture control module (9) via a second signal control line (14); and the timing control system (3) is connected to the laser (4) and the spectrometer (5) respectively. The analysis unit includes a component analysis system (7) and a hardness analysis system (8), the input terminals of which are connected to the output terminal of the spectrometer (5); The probe attitude control module (9) includes a drive motor (91), an angle displacement sensor (92), a linear displacement sensor (93), and an image transmission converter (94); the drive motor (91) is used to drive the detection probe (B) to move; the angle displacement sensor (92) is used to collect the swing angle of the fiber optic output lens group (10). The linear displacement sensor (93) is used to acquire the position of the fiber optic output lens group (10). The image transmission converter (94) is used to sample, quantize and encode the analog video signal captured by the camera to obtain a smaller digital signal.

2. A method for three-dimensional imaging of the composition and hardness detection of electromagnetic orbital deposition layers using the device described in claim 1, characterized in that, Includes the following steps: Step 1, Scan Path Control System (1) Sets the coordinates of the scanning starting point according to the input scan path. The probe posture control module (9) is controlled by the first signal control line (13) to move the detection probe B to the scanning start point; the probe posture control module (9) transmits the swing angle of the fiber optic output lens group (10) back to the autofocus control system (2) via the second signal control line (14). The probe attitude control module (9) transmits the position of the fiber optic output lens group (10) back to the autofocus control system (2) via the second signal control line (14). The probe attitude control module (9) controls the camera (11) to transmit the current field of view image back to the autofocus control system 2 via the second signal control line (14). The probe attitude control module (9) transmits the current scanning start coordinates back to the scanning path control system (1) via the first signal control line (13). ; Step 2: The scanning path control system (1) in the detection host (A) controls the drive motor (91) in the probe attitude control module (9) of the detection probe (B) according to the input scanning path, so as to drive the detection probe (B) to perform two-dimensional trajectory scanning on the surface of the electromagnetic emission track deposition layer; the autofocus control system (2) in the detection host (A) realizes the focusing and horizontal detection of the detection probe (B) by controlling the angular movement and stepping direction of the drive motor (91) in the probe attitude control module (9), so as to drive the detection probe (B) to perform depth direction scanning detection on the surface of the electromagnetic emission track deposition layer; the autofocus control system (2) controls the single-point trigger pulse number input according to the input single-point trigger pulse number. The number of pulse triggers of the laser (4) at a single point on the surface of the deposition layer is controlled to achieve length control in the depth direction; Step 3: The laser is fed into the detection probe (B) and refocused through the fiber optic output lens group (10), finally irradiating the current scanning point to generate plasma and its radiated light; when the number of trigger pulses reaches Then, the autofocus control system (2) inputs the autofocus completion command to the probe attitude control module (9); Step 4, the detection probe (B) passes through each scanning point in all scanning areas. Generated by subpulse laser irradiation The secondary plasma radiation light is focused into the transmission fiber (12) by the fiber output lens group (10), and then transmitted back to the detection host (A) in real time through the transmission fiber (12). Step 5: The plasma radiation light transmitted back to the detection host (A) is focused again into the spectrometer (5) through the fiber optic input lens group (6). The intensity of the plasma radiation light at each wavelength image point is expanded by the spectrometer (5) to obtain the LIBS spectrum of optical tomography. Step 6: Input the optical tomography LIBS spectrum into the component analysis system (7) and the hardness analysis system (8) for processing to obtain the actual content of all components to be analyzed in the current scanning area under each laser pulse. and the hardness of all scan points The detection host (A) outputs the three-dimensional imaging and hardness distribution results of the electromagnetic emission orbit deposition layer composition in the current scanning area.

3. The method for three-dimensional imaging of electromagnetic orbital deposition layer composition and hardness detection according to claim 2, characterized in that, The scan path includes the scan rate. Scanning space Axis resolution , Number of axis scan points Scanning space Axis resolution as well as Number of axis scan points .

4. The method for three-dimensional imaging of electromagnetic orbital deposition layer composition and hardness detection according to claim 2, characterized in that, Before triggering the laser (4), the autofocus control system (2) first transmits the current field-of-view image back from the probe attitude control module (9). The swing angle of the fiber optic output lens group (10) and location , perform horizontal detection and automatic focusing; then input a trigger pulse into the laser (4); after receiving the trigger pulse signal, the laser (4) outputs a pulsed laser into the fiber input lens group (6) for focusing, and after focusing, it is fed into the transmission fiber (12), and after being transmitted through the transmission fiber (12), it enters the detection probe (B).

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