A double-cone assembly observation and adjustment system for a laser fusion ignition target

Abstract

This invention provides a system for observing and adjusting the assembly of a double-cone laser fusion target, comprising: an observation module for observing the double cones of the laser fusion target; a vision processing module for receiving and processing images of the double cones observed by the observation system; an adjustment block for initially adjusting the parallelism of the double cones based on the processing results of the vision processing system; and an adjustment rod array for finely adjusting the assembly position of the double cones based on the processing results of the vision processing system. This invention combines computer vision automation with manual assembly, improving the precision of the assembly process of the double cones of the laser fusion target and providing a novel and efficient solution for laser fusion target assembly.

Description

Technical Field

[0001] This invention relates to the field of laser nuclear fusion, specifically to a laser fusion ignition target double-cone assembly observation and adjustment system. Background Technology

[0002] Nuclear fusion is the process by which two lighter atomic nuclei fuse into a heavier atomic nucleus, releasing energy. Controlled nuclear fusion is commonly known as the artificial sun because the sun operates on the principle of nuclear fusion reactions. Human understanding of thermonuclear fusion began with the hydrogen bomb explosion. In recent decades, humanity has hoped to invent a device that can effectively control the process of a hydrogen bomb explosion, allowing for a continuous and stable output of energy. Controlled nuclear fusion offers advantages such as abundant raw materials, excellent economic performance, safety and reliability, and no environmental pollution.

[0003] Laser inertial confinement fusion is a technological approach to controlled nuclear fusion, which uses lasers to heat a target to initiate a fusion reaction between nuclear atoms. The laser fusion ignition target is a crucial component in laser inertial confinement fusion experiments, and the assembly precision of the target determines the stability and success rate of the physical experiment. However, traditional laser fusion ignition target assembly and adjustment methods mostly rely on manual labor to complete multiple positioning and pressing processes, resulting in low efficiency.

[0004] A search of existing technologies revealed that Luan Fei et al. from the State Key Laboratory of Robotics Technology and Systems at Harbin Institute of Technology published an article titled "Automatic Precision Micro-Assembly System for Conical Shell Targets" in Robotics, 2016, 38(5):6. This article proposed a multi-manipulator precision micro-assembly system with micron-level positioning accuracy. It uses a lifting wavelet algorithm and employs three multi-degree-of-freedom manipulators to pick up and assemble parts of different shapes and materials. However, since it uses traditional recognition methods, it has stringent requirements for the image shooting environment and requires auxiliary mechanics for position recognition, making the assembly process complex. In addition, the multiple robotic arms make it impossible for humans to intervene in the assembly process, and the assembly error is entirely determined by the design accuracy of the system, without any secondary adjustment function. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a laser fusion ignition target double-cone assembly observation and adjustment system.

[0006] According to a first aspect of the present invention, a laser fusion ignition target biconical assembly observation and adjustment system is provided, comprising:

[0007] The observation module is used to observe the biconical laser fusion ignition target.

[0008] The visual processing module receives and processes the images of the laser fusion ignition target bicone observed by the observation system.

[0009] An adjustment block, which initially adjusts the parallelism of the double cones of the laser fusion ignition target based on the processing results of the vision processing system;

[0010] An adjustment rod array is used to finely adjust the assembly position of the double cones of the laser fusion ignition target based on the processing results of the vision processing system.

[0011] Preferably, the observation module includes:

[0012] Two observation cameras are placed orthogonally to capture images of the XY plane and its vertical plane of the laser fusion ignition target double cone, respectively. The distance between the observation cameras and the laser fusion ignition target double cone is 2 to 20 centimeters.

[0013] Preferably, the visual processing module includes:

[0014] A computer that receives and processes images acquired by the observation module.

[0015] Preferably, the computer receives and processes the images acquired by the observation module, including:

[0016] Convert the acquired image from RGB color space to HSV color space;

[0017] Binarize the image in the HSV color space;

[0018] Perform a closing operation on the binarized image to obtain a closed image;

[0019] Perform contour detection on the closed image to extract the contour of the image to be detected;

[0020] The image contour is subjected to roundness and concentricity detection, and the innermost circular contour is output.

[0021] The detection results and the circular outline are judged.

[0022] Preferably, the detection and judgment parameters are: roundness < 0.05 and center distance < 5 micrometers.

[0023] Preferably, the adjusting block includes a lower pressing block and an upper pressing block;

[0024] The lower clamping block has 2 to 10 strip-shaped protrusions with a height of 500 to 2000 micrometers and 1 step with a height of 5 to 2000 micrometers.

[0025] The upper pressing block is a square thin sheet with a thickness of 500 to 2000 micrometers.

[0026] When the lower and upper clamping blocks are clamped together, they can be used to adjust and limit the outer spacing of the double cones of the laser fusion ignition target.

[0027] Preferably, the process of obtaining the lower pressing block of the adjusting block includes:

[0028] Provide a substrate;

[0029] Positive photoresist is spin-coated onto the substrate as a mask. After pre-baking, exposure, development and post-baking, deep reactive ion etching or wet etching is used to obtain the first step and remove the photoresist.

[0030] Positive photoresist is spin-coated onto the first step as a mask. After pre-baking, exposure, development and post-baking, reactive ion etching or wet etching is used to obtain the second step, and the photoresist is removed.

[0031] The substrate is diced or laser-cut to release the adjustment block, resulting in the lower pressing block of the adjustment block.

[0032] Preferably, the adjustment rod array comprises four adjustment rods, which are evenly distributed on the outer edge of the double cone of the laser fusion ignition target; their length is 1 to 5 centimeters and their end diameter is 100 to 300 micrometers.

[0033] Preferably, the method is characterized in that the metal cone is displaced by the adjustment rod contacting the outer edge of the double cone of the laser fusion ignition target and applying force, thereby achieving fine adjustment of the assembly position of the double cone of the laser fusion ignition target.

[0034] Preferably, the process of obtaining the adjusting rod includes:

[0035] Provide a substrate;

[0036] Positive photoresist is spin-coated onto the substrate as a mask. After pre-baking, exposure, development and post-baking, deep reactive ion etching or wet etching is used to release the adjustment rod, obtain the hard part of the adjustment rod, and remove the photoresist.

[0037] Positive photoresist is spin-coated onto the hard portion of the adjustment rod as a mask, and patterning is performed through pre-baking, exposure, and development.

[0038] A flexible material is spin-coated onto the rigid portion of the adjustment rod and the photoresist;

[0039] Finally, the photoresist is removed to obtain the adjustment rod.

[0040] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0041] The laser fusion ignition target double-cone assembly observation and adjustment system in this embodiment of the invention detects and judges the assembly process of the laser fusion ignition target double cone. It uses computer vision to identify parameters such as the roundness and concentricity of the double cone parts during the assembly process, and uses secondary adjustment functions such as coarse adjustment of adjustment blocks and fine adjustment of adjustment rods to overcome the difficulty of micron-level precision assembly and improve the precision of the laser fusion ignition target double cone assembly process; it provides a new and efficient solution for laser fusion ignition target assembly. Attached Figure Description

[0042] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0043] Figure 1 This is a schematic diagram of the observation module and the double cone of the laser fusion ignition target in one embodiment of the present invention;

[0044] Figure 1 The numbers are respectively: observation camera 101, metal cone 102, schematic diagram of correctly installed metal cone 103, and schematic diagram of incorrectly installed metal cone 104;

[0045] Figure 2 This is a schematic diagram of the image processing flow in the visual processing module in a preferred embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the adjustment block in a preferred embodiment of the present invention;

[0047] Figure 3 The reference numerals are respectively: lower clamping block strip protrusion 301, lower clamping block first step 302, lower clamping block second step 303, upper clamping block 304;

[0048] Figure 4 This is a schematic diagram of the processing technology of the adjustment block in a preferred embodiment of the present invention;

[0049] Figure 5 This is a schematic diagram of the adjustment rod array and the double cone of the laser fusion ignition target in a preferred embodiment of the present invention;

[0050] Figure 5 The reference numerals are respectively: Adjusting rod 501, metal cone 502. Detailed Implementation

[0051] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0052] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limitations on this invention.

[0053] See Figure 1 This invention provides an embodiment of a laser fusion ignition target double-cone assembly observation and adjustment system, comprising an observation module, a vision processing module, an adjustment block, and an adjustment rod array; the observation module is used to observe the laser fusion ignition target double cone; the vision processing module receives and processes the images of the laser fusion ignition target double cone observed by the observation module; the adjustment block initially adjusts the parallelism of the laser fusion ignition target double cone according to the processing results of the vision processing module; the adjustment rod array finely adjusts the assembly position of the laser fusion ignition target double cone according to the processing results of the vision processing system.

[0054] In a preferred embodiment of the present invention, the observation module comprises two observation cameras 101; the vision processing module is computer hardware. The observation cameras 101 are used to observe the double cone 102 of the laser fusion ignition target, and then computer vision is used to assist in ensuring the precise assembly of the double cone of the laser fusion ignition target. Figure 1 As can be seen, the two observation cameras 101 are placed orthogonally, respectively used to capture images of the double cones of the laser fusion ignition target in the XY plane and their vertical plane. The distance between the observation cameras 101 and the double cones of the laser fusion ignition target is 2-20 cm. Among them, the frontal image of the double cones is used for processing and judgment, while the side image is only used for qualitative observation.

[0055] The observation camera 101 has functions such as focusing, adjusting ISO, adjusting shutter speed, adjusting aperture, adjusting exposure, and taking pictures. The computer hardware has functions such as camera image acquisition, image pre-processing, image feature recognition, visual data processing, and data communication. The observation camera and the vision processing system (computer hardware) communicate via wired communication protocols such as USB to exchange control data, transmit and process production data, and monitor assembly status. The vision processing system communicates via TCP / IP, with the main control system controlling camera image acquisition and vision processing, and providing feedback on the image recognition results of the completed vision processing, detection, and judgment.

[0056] See Figure 2 In a preferred embodiment of the present invention, the image processing procedure provided by the visual processing module is specifically as follows:

[0057] S100, due to the influence of lighting, shadows, focal length, etc., such as Figure 1 The image shown is prone to variations in the three components of the RGB color space with brightness, making it unsuitable for subsequent image processing. To address this, [further steps are needed to refine the image]. Figure 1 The two metal cone images shown are clearly separated from the background. The acquired metal cone images are converted from RGB color space to HSV color space according to the following formula (RGB represents red (R), green (G), and blue (B), r, g, and b represent red, green, and blue coordinates, respectively, and their values ​​are real numbers between 0 and 1; HSV uses hue H, saturation S, and luminance V to describe color changes, and H takes values ​​from 0° to 360°).

[0058]

[0059]

[0060] v = max

[0061] S200: Binarize the HSV image obtained in step S100 to extract the images of the two small holes in the metal cone.

[0062] S300. Perform a closing operation on the binarized image obtained in step S200. The closing operation filters the image by filling the concave corners of the image, which can fill small holes (holes) and close small cracks, while the overall position and shape remain unchanged, thus achieving image denoising.

[0063] S400. Perform contour detection on the closed-loop image obtained in step S300. Filter the image using a Gaussian kernel to remove noise points and smooth the image. Extract edge contours by taking partial derivatives and using gradient intensity and direction. Use non-maximum suppression to refine the extracted coarse edge contours. Use double thresholds to further filter noise, i.e., filter out unwanted lines, while ensuring the continuity of the contours. Extract the contours of the image to be detected.

[0064] S500: Perform roundness and concentricity detection on the contour obtained in step S400, and output the innermost circular contour.

[0065] S600: Judge the detection results output by S500 and the circular contour.

[0066] The parameters for detection and judgment are: roundness < 0.05 and center distance (the distance between the centers of the circular outlines of the two metal cones) < 5 micrometers.

[0067] Reference Figure 1 As shown in Figure 103, the two metal cones are correctly installed and their holes are concentric. The observation camera and vision processing system detect that both the roundness and the distance between their centers meet the judgment conditions. Figure 104 shows an incorrectly installed metal cone. The two metal cones are not concentric, and both the roundness and the distance between their centers do not meet the judgment conditions. Adjustment is required.

[0068] See Figure 3 In a preferred embodiment of the invention, a preferred structure for the adjustment block is provided, from Figure 3 It can be seen that it includes a lower clamping block and an upper clamping block.

[0069] The lower clamping block has 2 to 10 strip-shaped protrusions 301 with a height of 500 to 2000 micrometers. These protrusions contact the upper clamping block, defining the intermediate gap space when the lower and upper clamping blocks are clamped together. There is also a step with a height of 5 to 2000 micrometers. The first stage 302 of this step contacts the laser fusion ignition target support, and the second stage 303 contacts the double cones of the laser fusion ignition target. The height of the step defines the height difference between the outer edge of the double cones of the laser fusion ignition target and the laser fusion ignition target support. These defining functions are activated when the lower and upper clamping blocks 304 are clamped together, and can be used to adjust and limit the outer spacing of the double cones of the laser fusion ignition target.

[0070] See Figure 4 In a preferred embodiment of the present invention, a process for preparing a flexible lower clamping block using two different substrate materials is provided.

[0071] The first method, which uses SOI silicon wafers as substrates and adjusts the lower part of the pressing block, specifically includes the following processes:

[0072] S1: Reference Figure 4 As shown in (1), SOI silicon wafers are used as the substrate material for the sensor. The SOI silicon wafers contain a top silicon layer, a middle buried oxide layer and a bottom silicon structure. The SOI silicon wafers are ultrasonically cleaned in acetone, ethanol and deionized water for 5 minutes, then dried with nitrogen and baked in an oven at 180°C for 3 hours.

[0073] S2: Reference Figure 4 As shown in (2), 10 μm of positive photoresist (AZ4562) was applied to the top silicon layer of the SOI silicon wafer, and after photolithography and development, it was baked on a hot plate at 110°C for 10 minutes.

[0074] S3: Reference Figure 4 As shown in (3), the patterned top silicon is etched using the Bosch silicon etching process with etching parameters of 5000s and 500μm. This step forms strip-shaped bosses on the lower compaction block;

[0075] S4: Reference Figure 4 As shown in (4), the entire SOI silicon wafer is placed in acetone, ethanol and deionized water and ultrasonically cleaned for 5 minutes. Then it is dried with nitrogen and placed in an oven at 180°C for 3 hours. This step removes the photoresist in step S2.

[0076] S5: Reference Figure 4 As shown in (5), 3 μm of positive photoresist (HJ4010) was applied to the top silicon layer of the SOI silicon wafer, and after photolithography and development, it was baked on a hot plate at 110°C for 10 minutes.

[0077] S6: Reference Figure 4 As shown in (6), the patterned buried oxide layer was etched using inductively coupled plasma etching with etching parameters of 500 s and 20 μm. This step forms a step in the lower compacted bulk material;

[0078] S7: Reference Figure 4 As shown in (7), the entire SOI silicon wafer is placed in acetone, ethanol and deionized water and ultrasonically cleaned for 5 minutes. Then it is dried with nitrogen and placed in an oven at 180°C for 3 hours. This step removes the photoresist in step S5.

[0079] S8: Reference Figure 4 As shown in (8), the wafer cutting process is achieved using a DISCO3650 dicing machine. This step yields the lower clamping block of the adjustment block.

[0080] The second method uses a common silicon wafer as a substrate, and the processing of adjusting the lower part of the pressing block includes:

[0081] This embodiment provides a method for processing the lower clamping block of the silicon adjustment block, specifically including:

[0082] Step 1: Spin-coat photoresist onto a silicon substrate, and obtain a customized silicon strip protrusion structure mask after exposure and development;

[0083] Step 2: Use inductively coupled plasma etching to form a strip-shaped protrusion structure on the silicon substrate;

[0084] Step 3: Remove the photoresist;

[0085] Step 4: Spin-coat photoresist onto a silicon substrate, and obtain a customized silicon step structure mask after exposure and development;

[0086] Step 5: Use inductively coupled plasma etching to form a stepped structure on the silicon substrate;

[0087] Step 6: Use laser cutting equipment to perform wafer cutting. This step yields the lower clamping block of the adjustment block.

[0088] See Figure 5 In a preferred embodiment of the present invention, a preferred structure for an adjustment rod array is provided. As shown in the figure, the adjustment rod array includes four adjustment rods. The four adjustment rods are 1 to 5 cm long and have an end diameter of 100 to 300 micrometers. The four adjustment rods are evenly distributed on the outer edge of the double cone of the laser fusion ignition target. By contacting the adjustment rods 501 with the outer edge of the double cone of the laser fusion ignition target and applying force, the metal cone 502 can be displaced, thereby achieving fine adjustment of the assembly position of the double cone of the laser fusion ignition target. Specifically, by pressing the metal cone 502 with the adjustment rods 501, when one end is pressed, the other end of the metal cone 502 is easily lifted. By using multiple adjustment rods 501, the lifted part can be pressed down, balancing the position of the metal cone 502.

[0089] In a preferred embodiment of the present invention, taking the fabrication of a flexible lower clamping block from a silicon substrate material as an example, the processing and acquisition of the adjustment rod in the above embodiment will be further described, specifically including:

[0090] Step 1: Soak the silicon wafer in acetone, ethanol and deionized water respectively for ultrasonic cleaning for 5 minutes, then dry it with nitrogen and bake it in a 180℃ oven for 3 hours.

[0091] Step 2: Spray 5μm of positive adhesive (HJ6030) onto the front side of the silicon wafer, photolithography, development, and bake on a hot plate at 110℃ for 10 minutes;

[0092] Step 3: The patterned silicon is etched using Bosch silicon etching technology with etching parameters of 4000 s and 400 μm. This step yields the hard portion of the adjustment rod.

[0093] Step 4: Place the hard part of the adjustment rod into acetone, ethanol and deionized water and ultrasonically clean for 5 minutes. Then dry it with nitrogen and bake it in a 180°C oven for 3 hours. This step removes the photoresist in step 2.

[0094] Step 5: Spray 3μm of positive photoresist (HJ4010) onto the front side of the hardened part of the adjustment rod, then photolithography and development;

[0095] Step 6: Spin-coat PDMS onto the hard portion of the adjustment rod and the photoresist from Step 5;

[0096] Step 7: Place the adjustment rod in acetone, ethanol and deionized water and ultrasonically clean for 5 minutes, then dry it with nitrogen to obtain an adjustment rod with PDMS attached to the end.

[0097] The laser fusion ignition target double-cone assembly, observation, and adjustment system proposed in this invention combines computer automation with manual assembly. Compared to traditional manual assembly, it more accurately completes the assembly and observation of the laser fusion ignition target double cones. Through computer communication and image recognition technology, it achieves synchronous observation and identification of the actual assembly process, which helps improve the work efficiency and assembly accuracy of the laser fusion ignition target double-cone assembly process. These features will be beneficial to the practical application of laser fusion ignition targets.

[0098] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention. The above preferred features can be used in any combination without conflict.

Claims

1. A laser fusion ignition target double-cone assembly observation and adjustment system, characterized in that, include: The observation module is used to observe the biconical laser fusion ignition target. A visual processing module receives and processes images of the laser fusion ignition target bicone observed by the observation system. An adjustment block, which initially adjusts the parallelism of the double cones of the laser fusion ignition target based on the processing results of the vision processing module; The adjustment rod array finely adjusts the assembly position of the double cones of the laser fusion ignition target based on the processing results of the vision processing module. The adjusting block includes a lower pressing block and an upper pressing block; The lower clamping block has 2 to 10 strip-shaped protrusions with a height of 500 to 2000 micrometers and 1 step with a height of 5 to 2000 micrometers. The upper pressing block is a square thin sheet with a thickness of 500 to 2000 micrometers. When the lower and upper clamping blocks are clamped together, they can be used to adjust and limit the outer spacing of the double cones of the laser fusion ignition target.

2. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 1, characterized in that, The observation module includes: Two observation cameras are placed orthogonally to capture images of the XY plane and its vertical plane of the laser fusion ignition target double cone, respectively. The distance between the observation cameras and the laser fusion ignition target double cone is 2 to 20 centimeters.

3. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 1, characterized in that, The visual processing module includes: A computer that receives and processes images acquired by the observation module.

4. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 3, characterized in that, The computer receives and processes images acquired by the observation module, including: Convert the acquired image from RGB color space to HSV color space; Binarize the image in the HSV color space; Perform a closing operation on the binarized image to obtain a closed image; Perform contour detection on the closed image to extract the contour of the image to be detected; The image contour is subjected to roundness and concentricity detection, and the innermost circular contour is output. The results of the roundness and concentricity detections and the circular outline are used to make a judgment.

5. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 4, characterized in that, The parameters for detecting and judging roundness and concentricity are roundness and center distance. When roundness < 0.05 and center distance < 5 micrometers, the test is considered qualified.

6. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 1, characterized in that, The process of obtaining the lower pressing block of the adjustment block includes: Provide a substrate; Positive photoresist is spin-coated onto the substrate as a mask. After pre-baking, exposure, development and post-baking, deep reactive ion etching or wet etching is used to obtain the first step and remove the photoresist. Positive photoresist is spin-coated onto the first step as a mask. After pre-baking, exposure, development and post-baking, reactive ion etching or wet etching is used to obtain the second step, and the photoresist is removed. The substrate is diced or laser-cut to release the adjustment block, resulting in the lower pressing block of the adjustment block.

7. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 1, characterized in that, The adjustment rod array comprises four adjustment rods, which are evenly distributed on the outer edge of the double cone of the laser fusion ignition target; their length is 1-5 cm and their end diameter is 100-300 micrometers.

8. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 7, characterized in that, By contacting the adjusting rod with the outer edge of the double cone of the laser fusion ignition target and applying force, the metal cone is displaced and kept in balance, thus achieving fine adjustment of the assembly position of the double cone of the laser fusion ignition target.

9. The laser fusion ignition target double-cone assembly observation and adjustment system according to claim 1, characterized in that, The process of obtaining the adjustment rod includes: Provide a substrate; Positive photoresist is spin-coated onto the substrate as a mask. After pre-baking, exposure, development and post-baking, deep reactive ion etching or wet etching is used to release the adjustment rod, obtain the hard part of the adjustment rod, and remove the photoresist. Positive photoresist is spin-coated onto the hard portion of the adjustment rod as a mask, and patterning is performed through pre-baking, exposure, and development. A flexible material is spin-coated onto the rigid portion of the adjustment rod and the photoresist; Finally, the photoresist is removed to obtain the adjustment rod.

Images