LIBS heterogeneous sample detection and analysis system and method based on 3D mapping

Abstract

The invention discloses an LIBS (laser-induced breakdown spectroscopy) heterogeneous sample detection and analysis system and method based on 3D (three-dimensional) mapping. The system comprises a laser spectrum emission device for providing carrier waves required by LIBS, and a sample positioning and ablation point control and adjustment device for adjusting a heterogeneous sample detection position and accurately positioning a laser ablation position, the sample positioning and ablation point control adjusting device comprises a 3D scanning mechanism used for scanning the surface of a heterogeneous sample to obtain a three-dimensional model of the sample, and an electronic adjustable lens used for receiving laser emitted by the laser spectrum module and adjusting the focusing position. The electronic adjustable platform is used for adjusting an ablation point on the surface of the sample in cooperation with the electronic adjustable lens, LIBS and space mapping are combined, accurate detection and analysis of all position areas on the surface of the irregular heterogeneous sample are achieved through the electronic adjustable platform and the electronic adjustable lens, the consistency of laser focusing at all positions can be guaranteed, and the detection accuracy is improved. The accuracy of detection and analysis data is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of LIBS detection, and in particular to a LIBS heterogeneous sample detection and analysis system and method based on 3D mapping. Background Art

[0002] LIBS is an advanced atomic emission spectroscopic technique that uses a high-energy pulsed laser to generate a plasma by evaporating a sample. The plasma emits light over a range of wavelengths, which is analyzed to determine the elemental composition and concentration of the material. LIBS stands out from other spectroscopic techniques such as Raman spectroscopy and Fourier transform infrared spectroscopy because it can directly detect elemental composition with high sensitivity, including trace elements at parts per million levels. Its main advantage is that it can perform real-time in-situ analysis without complex sample preparation or stringent environmental conditions. LIBS is particularly suitable for dynamic detection scenarios because it can operate in harsh environments and analyze samples whether they are solid, liquid or gaseous. However, the complexity of the spectra produced by LIBS, affected by overlapping peaks, noise and matrix effects, can make accurate quantification challenging. These factors indicate that advanced computational techniques are needed to fully realize the potential of LIBS in applications such as pollution detection, environmental monitoring and industrial quality control. Another aspect is better detection of heterogeneous samples in laboratory detection scenarios, where LIBS can be combined with spatial mapping techniques to identify and analyze contaminants or specific elements in different regions of the sample. This approach enhances LIBS by enabling localized analysis of multicomponent samples, ensuring precise elemental characterization even in complex or layered matrices. These advances have great potential for application in fields such as materials science, forensic analysis, and environmental monitoring.

[0003] Contamination elements in heterogeneous samples need to be detected and precisely located within the sample for effective analysis and statistics. Traditional laser-induced breakdown spectroscopy (LIBS) systems usually provide spectral data but lack spatial positioning capabilities, resulting in a long time-consuming and low detection accuracy for heterogeneous samples, and the inability to guarantee the accuracy and precision of the analysis results. Summary of the invention

[0004] Technical purpose: In view of the shortcomings of the above-mentioned existing heterogeneous sample analysis and detection, the present invention discloses a LIBS heterogeneous sample detection and analysis system and method based on 3D mapping.

[0005] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution: A LIBS heterogeneous sample detection and analysis system based on 3D mapping comprises a laser spectrum emitting device for providing a carrier required by LIBS, and a sample positioning and ablation point control and adjustment device for adjusting the heterogeneous sample detection position and accurately positioning the laser ablation position; the sample positioning and ablation point control and adjustment device comprises a 3D scanning mechanism for scanning the surface of the heterogeneous sample to obtain a three-dimensional model of the sample, an electronically adjustable lens for receiving laser light emitted by a laser spectrum module and adjusting the focus position, and an electronically adjustable platform for fixing the heterogeneous sample and adjusting the ablation point on the sample surface according to the three-dimensional model obtained by the 3D scanning mechanism in cooperation with the electronically adjustable lens; the electronically adjustable platform and the electronically adjustable lens constitute a multi-freedom motion system to adjust the heterogeneous sample detection position.

[0006] Preferably, the electronically adjustable platform of the present invention has the degree of freedom in the X direction, the degree of freedom in the Y direction, the degree of freedom in the circumferential direction, and the degree of freedom in rotation that can adjust the tilt angle of the heterogeneous sample relative to the horizontal plane. The degree of freedom in the Z axis direction during the laser impact process is provided by changing the focal length of the electronically adjustable lens, thereby realizing the detection and analysis of various surface areas of the heterogeneous sample.

[0007] Preferably, the tilt angle of the rotational freedom of the present invention varies in the range of 1-30°.

[0008] Preferably, the 3D scanning mechanism of the present invention adopts a 3D camera or a laser radar.

[0009] Preferably, the laser spectrum emitting device of the present invention comprises a power supply, a laser, a reflector, a digital delay generator, an optical fiber light collecting probe and a spectrometer, wherein the reflector is arranged between the laser and the electronically adjustable lens to adjust the direction of the laser light path; the digital delay generator is electrically connected to the laser to adjust the time delay of the laser pulse; the optical fiber light collecting probe is connected to the spectrometer to collect and analyze the spectral signal of LIBS in real time.

[0010] Preferably, the laser (5) of the present invention is a Nd:YAG laser.

[0011] The present invention also discloses a heterogeneous sample detection and analysis method. Using the above-mentioned LIBS heterogeneous sample detection and analysis system based on 3D mapping, before performing heterogeneous sample detection, the heterogeneous sample is first scanned by a 3D scanning mechanism to establish a three-dimensional model, and the detection path and the adjustment strategy of the electronically adjustable platform and the electronically adjustable lens when performing detection and analysis on each detection area on the surface of the heterogeneous sample are determined, so that the laser beam of the electronically adjustable lens is irradiated to the surface of the heterogeneous sample detection area to perform laser LIBS detection.

[0012] Preferably, when testing heterogeneous samples, the present invention first performs an initial scan of the sample surface, performs 3D mapping and LIBS spectral analysis to create a baseline map of the heterogeneous sample and determine the surface characteristics of the sample and the location of potential contaminants; then, based on the analysis results, multiple iterative scans and analyses are performed on the area of ​​interest to finally complete a comprehensive scan and test of the heterogeneous sample.

[0013] Preferably, when performing multiple iterative scans and analyses, the present invention processes the LIBS spectral data of each scan through a deep learning model, and corresponds it to the three-dimensional model of the heterogeneous sample, determines the area of ​​interest for detection based on the scanning detection requirements, establishes a confidence map on the three-dimensional model of the heterogeneous sample, and performs path planning and laser parameter control for the next scanning detection based on the distribution of the detection area on the confidence map.

[0014] Beneficial effects: The LIBS heterogeneous sample detection and analysis system and method based on 3D mapping disclosed in the present invention has the following beneficial effects: 1. The present invention combines LIBS with spatial mapping, and uses an electronically adjustable platform and an electronically adjustable lens to achieve accurate detection and analysis of various position areas on the surface of irregular heterogeneous samples, which can ensure the consistency of laser focusing at each position and the accuracy of detection and analysis data. It is suitable for laboratories and industrial applications that require rapid and high-throughput analysis of samples with complex geometric shapes.

[0015] 2. When detecting and analyzing the surface of heterogeneous samples, the present invention plans the detection path through the constructed three-dimensional model, and through iterative scanning and analysis, accurately detects the area of ​​interest of the heterogeneous sample step by step, and can optimize the scanning path to improve the detection and analysis efficiency.

[0016] 3. The present invention utilizes a deep learning model to establish a surface contamination map and a confidence map of heterogeneous samples based on detection requirements and scanning detection results, thereby realizing targeted detection and analysis of specific areas on the sample surface, and can adjust the laser parameters accordingly. Compared with the method of directly using the entire laser to perform a comprehensive scan to obtain a spectrum for analysis, the present invention can accurately control the detection stage and perform customized operations based on detection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0018] Figure 1 This is the overall structure diagram of the detection and analysis system of the present invention; Figure 2 This is a structural diagram of the electronic adjustable platform of the present invention; Among them, 1-3D scanning mechanism, 2-electronically adjustable lens, 3-electronically adjustable platform, 4-power supply, 5-laser, 6-reflector, 7-digital delay generator, 8-optical fiber light collecting probe, 9-spectrometer, 10-control unit, 11-display, 12-computer. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are set forth herein below. Each embodiment and example is provided by way of explanation of the apparatus, composition and materials of the present disclosure, rather than limitation. On the contrary, the following description provides a convenient illustration of an exemplary embodiment for implementing the present disclosure. In fact, it will be clear to those skilled in the art that various modifications and variations may be made in the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0020] like Figure 1 and Figure 2 As shown, the present invention discloses a LIBS heterogeneous sample detection and analysis system based on 3D mapping, comprising a laser spectrum emitting device for providing a carrier required by LIBS, and a sample positioning and ablation point control and adjustment device for adjusting the heterogeneous sample detection position and accurately positioning the laser ablation position; the sample positioning and ablation point control and adjustment device comprises a 3D scanning mechanism 1 for scanning the surface of the heterogeneous sample to obtain a three-dimensional model of the sample, an electronically adjustable lens 2 for receiving the laser emitted by the laser spectrum module and adjusting the focus position, and an electronically adjustable platform 3 for fixing the heterogeneous sample and adjusting the ablation point on the sample surface according to the three-dimensional model obtained by the 3D scanning mechanism 1 in cooperation with the electronically adjustable lens 2. The multi-freedom motion system is formed by the electronically adjustable platform 3 and the electronically adjustable lens 2 to adjust the heterogeneous sample detection position. The adjustment of the electronically adjustable platform 3 and the electronically adjustable lens 2 can be controlled by a control unit 10 of a preset control program, and the posture of the heterogeneous sample is adjusted based on the sample detection requirements.

[0021] like Figure 2As shown, based on the use requirements of the present invention, the electronically adjustable platform 3 has the degree of freedom in the X direction, the degree of freedom in the Y direction, the degree of freedom of rotation in the circumferential direction, and the degree of freedom of rotation that can adjust the tilt angle of the heterogeneous sample relative to the horizontal plane, and the tilt angle of the degree of freedom of rotation varies in the range of 1-30°; wherein the degree of freedom in the X direction and the degree of freedom in the Y direction are realized by the slide rail structure, the degree of freedom of rotation in the circumferential direction is driven by a rotating component such as a motor to rotate the platform in the circumferential direction, and the degree of freedom of rotation is realized by changing the relative height of the platform surface by a lifting component, and specifically, the slide rail structure can be set at the bottom, and on the moving end of the slide rail structure A rotating component is set, and then the corresponding lifting component and platform are installed at the driving end of the rotating component, so as to realize the integration of multiple degrees of freedom. As for the drive of each degree of freedom, it is realized by using an electronic control device. The selection of the equipment is based on the actual driving force and the control accuracy requirements and is confirmed by technical personnel in this field. The degree of freedom in the Z-axis direction during the laser impact process is provided by rotating the focal length of the electronically adjustable lens 2, so as to realize the detection and analysis of various surface areas of the heterogeneous sample. The number of degrees of freedom of the electronically adjustable platform 3 can also be increased or decreased based on the different sample objects to be detected, and it is only necessary to ensure that it can meet the requirements of heterogeneous sample detection.

[0022] The 3D scanning mechanism 1 of the present invention adopts a 3D camera or a laser radar, and other devices capable of building a three-dimensional model can also be used as a substitute; the laser spectrum emitting device includes a power supply 4, a laser 5, a reflector 6, a digital delay generator 7, an optical fiber light collecting probe 8 and a spectrometer 9, wherein the reflector 6 is arranged between the laser 5 and the electronically adjustable lens 2 to adjust the direction of the laser light path; the digital delay generator 7 is electrically connected to the laser 5 to adjust the time delay of the laser pulse; the optical fiber light collecting probe 8 is connected to the spectrometer 9 to collect the spectrum signal of LIBS in real time for collection and analysis, and can also be equipped with a display 11 and a computer 12 according to the needs for real-time observation and data storage, so as to be analyzed and utilized later. The laser 5 of the present invention adopts an Nd:YAG laser, which is composed of a main laser head and an internal optical device for amplification and wavelength selection. In the main laser head, the laser beam is generated using a gain medium (such as an Nd:YAG crystal); the laser 5 and other electrical equipment in the laser spectrum emitting device can be powered by the electrically connected power supply 4.

[0023] The present invention also discloses a heterogeneous sample detection and analysis method, which uses the above-mentioned LIBS heterogeneous sample detection and analysis system based on 3D mapping. Before performing heterogeneous sample detection, the heterogeneous sample is first scanned by a 3D scanning mechanism to establish a three-dimensional model, determine the detection path and the adjustment strategy of the electronically adjustable platform and the electronically adjustable lens when performing detection and analysis on each detection area on the surface of the heterogeneous sample, so that the laser beam of the electronically adjustable lens is irradiated to the surface of the heterogeneous sample detection area to perform laser LIBS detection. Through the scanning method of the present invention, the focal length of the electronically adjustable lens 2 is adjusted in real time on the heterogeneous sample with a complex surface, ensuring that the laser beam maintains a consistent focus on an uneven or complex surface, and the laser spot size is expanded or reduced according to the curvature or depth of the sample, thereby achieving comprehensive ablation of flat and uneven surfaces.

[0024] Generally, heterogeneous samples that require 3D mapping detection and analysis have surfaces with complex curved structures. When conducting detection, if traditional laser scanning detection methods are directly used, it is impossible to fully detect all positions of the sample, and the overall scanning takes a long time, which affects the efficiency of detection and analysis.

[0025] In order to improve the detection efficiency and realize targeted and accurate detection and analysis of the contaminated area or other areas of interest of heterogeneous samples, the present invention first performs an initial scan on the sample surface, performs 3D mapping and LIBS spectral analysis to create a baseline map of the heterogeneous sample and determine the surface characteristics of the sample and the location of potential pollutants; then, according to the analysis results, the area of ​​interest is scanned and analyzed multiple times iteratively, and finally completes the comprehensive scanning and detection of the heterogeneous sample; the area of ​​interest can be an area with a high concentration of pollutants, an irregular surface or an unscanned area, etc., which can be set by the detection personnel based on their own research needs to achieve customized detection. .

[0026] The present invention processes the LIBS spectral data of each scan through a deep learning model when performing multiple iterative scans and analyses, and the deep learning model processes inputs from the LIBS spectral data and the 3D map of the sample. The spectral data includes emission lines for classifying elements and contaminants, while the 3D map provides information about surface irregularities, curvatures, and unscanned areas. Using these data, the model can identify areas of interest, such as areas with high contamination signals, unscanned areas, or areas where the laser focus is inconsistent. Then, a confidence map is generated to highlight areas that need further scanning to improve accuracy or resolution as high priority areas. Based on this feedback, the subsequent scanning path is updated in real time to guide the laser to focus on high priority areas. In addition, the system dynamically adjusts laser parameters such as focus and intensity, as well as platform movement, including rotation and tilt, to optimize the scanning of these areas. After each scanning stage, the newly acquired data is fed back into the deep learning model, so that the analysis can be iteratively improved and the scanning process in the subsequent stages can be further optimized; the scanning path or the corresponding detection area changes will be dynamically optimized to focus on these areas to ensure more detailed and accurate analysis. The laser focus and intensity can also be adjusted based on the surface geometry and contaminant type identified in the previous scan. Finally, a comprehensive scan is performed on any remaining areas or regions that require higher confidence, achieving progressive refinement of the entire scanning and analysis process, improving the spatial resolution and spectral accuracy at each stage, and performing comprehensive detection and analysis of heterogeneous samples on complex surfaces. The number of scans required for heterogeneous samples of the present invention depends on the complexity of the sample geometry, the distribution of contaminants, and the specific analytical requirements of the study. The number of scans is flexible and can be adjusted by the user. For highly complex or irregular samples, more scans may be required to ensure complete coverage and accurate analysis. For simpler samples, the number of scans can be reduced accordingly.

Claims

1. A LIBS heterogeneous sample detection and analysis system based on 3D mapping, characterized in that: The invention comprises a laser spectrum emission device for providing a carrier required for LIBS, and a sample positioning and ablation point control and adjustment device for adjusting the detection position of a heterogeneous sample and accurately positioning the laser ablation position; the sample positioning and ablation point control and adjustment device comprises a 3D scanning mechanism (1) for scanning the surface of a heterogeneous sample to obtain a three-dimensional model of the sample, an electronically adjustable lens (2) for receiving laser light emitted by a laser spectrum module and adjusting the focus position, and an electronically adjustable platform (3) for fixing the heterogeneous sample and adjusting the ablation point on the sample surface according to the three-dimensional model obtained by the 3D scanning mechanism (1) in cooperation with the electronically adjustable lens (2); the electronically adjustable platform (3) and the electronically adjustable lens (2) constitute a multi-freedom motion system for adjusting the detection position of the heterogeneous sample.

2. A LIBS heterogeneous sample detection and analysis system based on 3D mapping according to claim 1, characterized in that: The electronically adjustable platform (3) has an X-direction degree of freedom, a Y-direction degree of freedom, a circumferential rotational degree of freedom, and a rotational degree of freedom capable of adjusting the tilt angle of the heterogeneous sample relative to the horizontal plane. The electronically adjustable platform (3) provides a Z-axis degree of freedom during the laser impact process by changing the focal length of the electronically adjustable lens (2), thereby realizing detection and analysis of various surface areas of the heterogeneous sample.

3. A LIBS heterogeneous sample detection and analysis system based on 3D mapping according to claim 2, characterized in that: The tilt angle of the rotational freedom varies in the range of 1-30°.

4. The LIBS heterogeneous sample detection and analysis system based on 3D mapping according to claim 1, characterized in that: The 3D scanning mechanism (1) uses a 3D camera or a laser radar.

5. The LIBS heterogeneous sample detection and analysis system based on 3D mapping according to claim 1, characterized in that: The laser spectrum emission device comprises a power supply (4), a laser (5), a reflector (6), a digital delay generator (7), an optical fiber light collection probe (8) and a spectrometer (9), wherein the reflector (6) is arranged between the laser (5) and the electronically adjustable lens (2) to adjust the direction of the laser light path; the digital delay generator (7) is electrically connected to the laser (5) to adjust the time delay of the laser pulse; and the optical fiber light collection probe (8) is connected to the spectrometer (9) to collect and analyze the spectral signal of LIBS in real time.

6. A LIBS heterogeneous sample detection and analysis system based on 3D mapping according to claim 5, characterized in that: The laser (5) is a Nd:YAG laser.

7. A method for detecting and analyzing heterogeneous samples, using the LIBS heterogeneous sample detection and analysis system based on 3D mapping according to any one of claims 1 to 6, characterized in that: Before conducting heterogeneous sample detection, the heterogeneous sample is first scanned by a 3D scanning mechanism to establish a three-dimensional model, determine the detection path and the adjustment strategy of the electronically adjustable platform and the electronically adjustable lens for detection and analysis of each detection area on the surface of the heterogeneous sample, so that the laser beam of the electronically adjustable lens is irradiated to the surface of the heterogeneous sample detection area for laser LIBS detection.

8. A heterogeneous sample detection and analysis method according to claim 7, characterized in that: When testing heterogeneous samples, an initial scan of the sample surface is performed, followed by 3D mapping and LIBS spectral analysis to create a baseline map of the heterogeneous sample and determine the sample surface characteristics and potential contaminant locations; Then, based on the analysis results, the area of ​​interest is scanned and analyzed iteratively multiple times, ultimately completing a comprehensive scanning and detection of the heterogeneous sample.

9. A heterogeneous sample detection and analysis method according to claim 8, characterized in that: During multiple iterative scans and analyses, the LIBS spectral data of each scan is processed by a deep learning model and matched with the three-dimensional model of the heterogeneous sample. The area of ​​interest for detection is determined based on the scanning and detection requirements, and a confidence map is established on the three-dimensional model of the heterogeneous sample. Based on the distribution of the detection area on the confidence map, path planning and laser parameter control for the next scanning and detection are performed.

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