A method and system for laser precision cleaning of composite surfaces

Abstract

The application provides a laser precision cleaning method and system for a composite material surface, comprising a laser generating unit, a beam scanning and focusing unit, a real-time monitoring and feedback unit and a central processing controller, the laser generating unit is used for generating pulse laser for cleaning, the beam scanning and focusing unit is used for controlling the laser beam to scan on the workpiece surface, the real-time monitoring and feedback unit comprises a CCD visual sensor and a plasma spectrum sensor, the CCD visual sensor is used for collecting image information of the cleaning area, the plasma spectrum sensor is used for analyzing characteristic spectrum generated by plasma excitation material, and the central processing controller is used for receiving the plasma spectrum and image information and sending laser parameter adjustment instructions. The application can identify the change of the material composition of the cleaning interface in real time, realize selective and non-destructive removal of the surface coating, and effectively avoid thermal damage and mechanical damage to the composite material substrate.

Description

Technical Field

[0001] This invention relates to the field of laser cleaning technology, and in particular to a laser precision cleaning method and system for composite material surfaces. Background Technology

[0002] Laser cleaning, as a "green" cleaning technology, uses a high-energy laser beam to irradiate the surface of a workpiece, causing surface contaminants, coatings, oxides, etc., to instantly vaporize, vibrate, peel off, or activate, thereby achieving the purpose of cleaning. Compared with traditional sandblasting and chemical cleaning, it has advantages such as no grinding, non-contact, no chemical pollution, and a high degree of automation. Currently, laser cleaning technology has been widely used in fields such as degreasing metal molds, removing paint from aluminum alloy skins in the aerospace industry, and cultural relic restoration.

[0003] However, with the widespread application of advanced composite materials, especially carbon fiber reinforced resin matrix composites and fiberglass, in aerospace, high-end transportation, and sporting goods, the need for surface cleaning during maintenance, repair, and refurbishment is becoming increasingly urgent. These composite materials are typically coated with protective paint layers, adhesive films, or have accumulated stubborn contaminants during use. Existing mainstream laser cleaning technologies exhibit the following technical problems when dealing with these materials: 1. The thermal damage threshold of the composite matrix is ​​low, making it difficult to precisely control the laser energy input, which can easily lead to irreversible damage to the matrix resin and severely weaken the mechanical properties of the material; 2. The existing process parameter library for laser cleaning technology has limitations, while the composite material system is complex, and the static parameter library cannot adapt to the dynamic and individual differences in the cleaning process, resulting in poor universality.

[0004] In summary, existing laser cleaning technologies are mainly derived from the cleaning practices of homogeneous materials with high damage thresholds, such as metals. When directly transplanted or simply modified and applied to composite materials, they suffer from systemic deficiencies in terms of cleaning safety, accuracy, and intelligent adaptability. Summary of the Invention

[0005] The purpose of this invention is to provide a laser precision cleaning method and system for composite material surfaces, which can identify changes in the composition of the cleaning interface in real time and make "real-time decisions" and "precise controls" of the laser action accordingly. This new method and system unlocks the full application potential of laser cleaning in the field of high-end composite material maintenance, and can achieve selective and non-destructive removal of surface coatings, effectively avoiding thermal and mechanical damage to the composite material matrix.

[0006] The technical solution adopted by this invention to solve its technical problem is: In a first aspect, the present invention provides a laser precision cleaning system for composite material surfaces, comprising a laser generating unit, a beam scanning and focusing unit, a real-time monitoring and feedback unit, and a central processing controller. The laser generating unit is used to generate pulsed laser for cleaning, the beam scanning and focusing unit is used to control the laser beam to scan the workpiece surface, the real-time monitoring and feedback unit includes a CCD vision sensor and a plasma spectral sensor, the CCD vision sensor is used to acquire image information of the cleaning area, the plasma spectral sensor is used to analyze the characteristic spectrum generated by the plasma-excited material, and the central processing controller is used to receive the plasma spectrum and image information, identify the composition of the material being treated in real time, and send laser parameter adjustment commands to the laser generating unit and the beam scanning and focusing unit.

[0007] Furthermore, the beam scanning and focusing unit includes a galvanometer and an F-θ lens, which are used to control the laser beam to scan a predetermined trajectory on the workpiece surface and keep the focal point on the cleaning surface.

[0008] Furthermore, the plasma spectral sensor employs an optical fiber probe, which is positioned near the exit of the galvanometer. The acquisition end of the plasma spectral sensor is pointed towards the center region of the plasma plume to optimize signal acquisition efficiency and avoid direct laser damage.

[0009] Furthermore, the central processing controller includes an adaptive control module and an information analysis module. The information analysis module is used to compare the real-time acquired plasma spectrum with the pre-stored coating characteristic spectrum and substrate characteristic spectrum to determine whether the current laser action target is a coating or a substrate. The adaptive control module is used when the current action target is determined to be a coating or a substrate. If the current target is determined to be a coating, the first laser parameter set is maintained or optimized. The first laser parameter set is a combination of laser parameters used to effectively remove the coating. If the target of the current action is determined to be the substrate, switch to the second laser parameter set whose energy density does not exceed 30% of the energy density corresponding to the first laser parameter set, or stop the laser output to that point.

[0010] Furthermore, the wavelength of the pulsed laser generated by the laser generating unit is 355nm-1064nm, and the pulse width generated by the laser generating unit is on the order of nanoseconds, picoseconds, or femtoseconds.

[0011] Secondly, the present invention provides a cleaning method for a laser precision cleaning system for composite material surfaces as described in any one of the above-mentioned methods, comprising the following steps: S1: Based on the known physicochemical properties of the composite material and coating to be cleaned, preset the initial laser parameters and the spectral feature database for material identification; S2: The laser is activated to scan and clean the surface of the composite material. The laser beam scans the cleaning area along a preset trajectory, and the plasma spectral sensor and CCD vision sensor begin to collect data synchronously. The composite material is preferably a carbon fiber reinforced resin matrix composite or fiberglass. S3: The central processing controller compares the real-time plasma spectrum with the characteristic spectra in the database to identify whether the material being ablated by the laser is a coating or a composite matrix. S4: Based on the identification results, adjust the laser power, scanning speed, or on / off status in real time to ensure that damage to the substrate is avoided while removing the coating. Specifically, "adjusting laser parameters in real time based on identification results" means: when a coating characteristic spectrum is identified, maintain the current parameters; when a substrate characteristic spectrum is identified, immediately reduce the laser power and / or increase the scanning speed.

[0012] Furthermore, in step S2, during the process of scanning and cleaning the surface of the composite material with the laser, images of the cleaning area are simultaneously acquired, and the image color and morphology change information are fused with the plasma spectral analysis results to improve the accuracy of state recognition.

[0013] In summary, the beneficial effects of the present invention are as follows: This invention relates to a laser precision cleaning method and system for composite material surfaces, applicable to fields with extremely high maintenance requirements for composite materials, such as aerospace, high-end sports equipment, and wind turbine blades. Through real-time feedback from plasma spectroscopy, the laser action can be rapidly adjusted or stopped the instant the cleaning reaches the substrate. Furthermore, this invention can automatically adjust laser parameters based on real-time changes in material composition during the cleaning process, adapting to coatings of different thicknesses and aging levels, achieving identification and differentiation between the "coating" and the "substrate," thereby enabling precise selective cleaning. This invention provides a laser precision cleaning method and system for composite material surfaces. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the laser precision cleaning system for composite material surfaces according to the present invention; Figure 2 This is a flowchart of the laser precision cleaning method for composite material surfaces according to the present invention; Figure 3 This is a schematic diagram of the installation of the plasma spectral sensor of the present invention. Detailed Implementation

[0016] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0017] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a mechanical connection or an electrical connection; it can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0018] Please see Figure 1-3 In a first aspect, the present invention provides a laser precision cleaning system for composite material surfaces, comprising a laser generating unit (100), a beam scanning and focusing unit (200), a real-time monitoring and feedback unit (300), and a central processing controller (400). The laser generating unit is used to generate pulsed laser for cleaning, the beam scanning and focusing unit is used to control the laser beam to scan the workpiece surface, and the real-time monitoring and feedback unit (300) includes a CCD vision sensor (310) and a plasma spectral sensor (320). The CCD vision sensor is used to acquire image information of the cleaning area, the plasma spectral sensor is used to analyze the characteristic spectrum generated by the plasma-excited material, and the central processing controller is used to receive the plasma spectrum and image information, identify the composition of the material being treated in real time, and send laser parameter adjustment commands to the laser generating unit and the beam scanning and focusing unit.

[0019] Furthermore, the beam scanning and focusing unit includes a galvanometer (210) and an F-θ lens (220), which are used to control the laser beam to scan a predetermined trajectory on the workpiece surface and keep the focal point on the cleaning surface.

[0020] Furthermore, the plasma spectral sensor employs an optical fiber probe, which is positioned near the exit of the galvanometer. The acquisition end of the plasma spectral sensor is pointed towards the center region of the plasma plume to optimize signal acquisition efficiency and avoid direct laser damage.

[0021] Specifically, the probe is mounted laterally at a 45-degree angle at the exit position of the galvanometer, and the acquisition end of the plasma spectral sensor is pointed to the plasma plume center region about 3 mm behind the laser focus, in order to optimize signal acquisition efficiency and avoid direct laser damage.

[0022] Furthermore, the central processing controller (400) includes an adaptive control module (410) and an information analysis module (420). The information analysis module is used to compare the real-time acquired plasma spectrum with the pre-stored coating characteristic spectrum and substrate characteristic spectrum to determine whether the current laser action target is a coating or a substrate. The adaptive control module is used when the current action target is determined to be a coating or a substrate. If the current target is determined to be a coating, the first laser parameter set (including power P1, scanning speed V1, and pulse frequency f1) is maintained or optimized. The first laser parameter set is a combination of laser parameters used to effectively remove the coating. If the target of the current action is determined to be a substrate, switch to the second laser parameter set (including power P2, scanning speed V2, and pulse frequency f2) whose energy density does not exceed 30% of the energy density corresponding to the first laser parameter set, or stop the laser output to that point.

[0023] Specifically, the information analysis module identifies materials by calculating the intensity ratio R = I_coat / (I_coat+I_sub) of the coating characteristic peak to the matrix characteristic peak, where I_coat is the integrated intensity of the coating characteristic peak and I_sub is the integrated intensity of the matrix characteristic peak. The adaptive control module's parameter adjustment benefits from high-speed signal processing circuitry and pre-loaded algorithms, resulting in a system control delay of less than 1ms.

[0024] Furthermore, the pulsed laser generated by the laser generating unit has a wavelength of 355nm-1064nm and a pulse width on the order of nanoseconds, picoseconds, or femtoseconds.

[0025] Secondly, the present invention provides a laser precision cleaning method using any of the systems described above, comprising the following steps: S1: Based on the known physicochemical properties of the composite material and coating to be cleaned, preset the initial laser parameters and the spectral feature database for material identification; S2: The laser is activated to scan and clean the surface of the composite material. The laser beam scans the cleaning area along a preset trajectory, and the plasma spectral sensor and CCD vision sensor begin to collect data synchronously. The composite material is preferably a carbon fiber reinforced resin matrix composite or fiberglass. S3: The central processing controller compares the real-time plasma spectrum with the characteristic spectra in the database to identify whether the material being ablated by the laser is a coating or a composite matrix. S4: Based on the identification results, adjust the laser power, scanning speed, or on / off status in real time to ensure that damage to the substrate is avoided while removing the coating. Specifically, "adjusting laser parameters in real time based on identification results" means: when a coating characteristic spectrum is identified, maintain the current parameters; when a substrate characteristic spectrum is identified, immediately reduce the laser power and / or increase the scanning speed.

[0026] Furthermore, in step S2, during the process of scanning and cleaning the surface of the composite material with the laser, images of the cleaning area are simultaneously acquired, and the image color and morphology change information are fused with the plasma spectral analysis results to improve the accuracy of state recognition.

[0027] Specifically, the laser generating unit generates pulsed lasers, preferably fiber lasers or ultraviolet lasers, with pulse widths in the nanosecond to picosecond range and wavelengths in the 355nm to 1064nm range. The beam scanning and focusing unit includes a galvanometer system and an F-θ lens, used to control the laser beam to scan a predetermined trajectory on the workpiece surface and keep the focus on the cleaned surface. The signal analysis module analyzes the elemental characteristic spectra of the plasma spectrum in real time to identify whether the material being ablated is a "coating" or a "matrix". (For example, a coating containing specific organic pigments will show characteristic peaks of carbon and nitrogen elements, as well as characteristic peaks of specific metal ions in its spectrum; while when the spectrum shows characteristic peaks of carbon fibers or silicon and oxygen elements of the matrix resin, it is determined that the cleaning has reached the matrix). The adaptive control module adjusts parameters such as laser power P, scanning speed V, and pulse frequency f of the laser generating unit and beam scanning unit in real time based on the identification results of the signal analysis module.

[0028] Specifically, the present invention provides a laser precision cleaning method using the above system, comprising the following steps: S1: Parameter preset: Based on the known physicochemical properties of the composite material and coating to be cleaned, preset the initial laser parameters (power P0, scanning speed V0, frequency f0) and spectral feature database (including coating feature spectrum and matrix feature spectrum).

[0029] S2: Start Cleaning and Real-time Monitoring: Start the system, the laser beam scans the cleaning area along the preset trajectory, and at the same time the plasma spectral sensor and CCD vision sensor begin to collect data synchronously.

[0030] S3: Spectral Analysis and Status Judgment: The central processing controller compares the real-time acquired plasma spectrum with the characteristic spectra in the database. If a coating characteristic spectrum is detected, it is determined that "the coating is being cleaned," and the adaptive control module maintains the current laser parameters or optimizes them within a small range. If a substrate characteristic spectrum is detected, it is determined that "the substrate is about to be or has already been damaged," and the adaptive control module immediately issues an instruction to significantly reduce the laser power (e.g., reduce it to 10%-30% of the initial power) and / or increase the scanning speed, or directly skip the scanning point; S4: Visual Assisted Judgment and Secondary Confirmation: The CCD visual sensor synchronously monitors the shape and color changes of the cleaning area. When the spectral analysis is ambiguous or contradictory, it combines image information (such as the color changing from the coating color to the base color) to make a comprehensive judgment, thereby improving the accuracy of status recognition.

[0031] S5: Cycle and Completion: Repeat steps S2-S4 until the coating in the entire target cleaning area is completely removed and the system no longer detects any substrate damage signals, at which point the cleaning process ends.

[0032] For example, in one implementation, a piece of carbon fiber reinforced polymer (CFRP) skin with old polyurethane topcoat on the wing of an aircraft type is used as the cleaning target. After long-term service, the paint layer on this component has aged and partially damaged, requiring complete removal of the old paint layer without damaging the substrate for repainting. The system configuration and preparation adopt the following... Figure 1 The laser precision cleaning system shown uses a fiber-optic output nanosecond pulsed laser in the laser generation unit (100), with a center wavelength of 355nm (ultraviolet band). This wavelength has a high absorption rate for organic coatings (polyurethane paint) and a relatively low absorption rate for carbon fibers in the CFRP matrix, which is beneficial for selective ablation. The laser has a maximum average power of 20W, a pulse width of 100ns, and a pulse frequency adjustable in the range of 1-200kHz. The beam scanning and focusing unit (200) uses a high-speed two-dimensional galvanometer system with an F-θ flat-field focusing lens to focus the beam diameter to 50μm. This unit is fixed to the end effector of a six-axis robotic arm, enabling tracking and precise scanning of complex surfaces with large curvatures.

[0033] The plasma spectral sensor (320) employs a broadband CCD spectrometer with a quartz fiber optic probe, having a spectral response range of 200 nm to 850 nm and a resolution better than 0.1 nm. The fiber optic probe is pointed at approximately 45 degrees to the center of the plasma plume about 3 mm behind the laser application point to acquire the optimal signal.

[0034] The CCD vision sensor (310) employs a high-resolution color industrial camera, coaxially integrated with the laser beam, to observe the morphology and color changes of the cleaning area in real time. The central processing controller (400) uses an industrial-grade computer with a built-in signal analysis module (420) and adaptive control module (410). The signal analysis module runs a fast recognition algorithm based on the ratio of characteristic peak intensities. Before the cleaning operation, initial parameters are preset: based on preliminary experiments, a set of relatively conservative initial laser process parameters are set: average power P0 = 8W, scanning speed V0 = 1200 mm / s, pulse frequency f0 = 80kHz, and scan line spacing 0.03mm.

[0035] A spectral feature database was constructed. In non-critical areas of the workpiece, the paint layer was lightly ablated using a low-power laser, and its plasma characteristic spectra were collected and stored. Analysis revealed that the main characteristics of this polyurethane paint were the CN molecular band near 388.3 nm, the O atom feature lines at 777.2 nm and 844.6 nm (from additives in the paint layer), and the Mg ion line at 518.4 nm (from pigments).

[0036] In the exposed CFRP matrix area at the workpiece edge, a very low-power laser was used for slight irradiation, and the matrix characteristic spectrum was collected and stored. Typical features included a strong C atom characteristic line at 247.8 nm (mainly from carbon fibers) and a Si atom characteristic line at 288.2 nm (from silica filler in the matrix resin). These characteristic peaks and their typical intensity ranges were stored in a database as templates for real-time comparison.

[0037] See laser cleaning and intelligent control process. Figure 2 The flowchart shown illustrates the cleaning process. Start-up and initial cleaning: The robot begins moving along a preset path, and the laser emits light with the aforementioned initial parameters (P0, V0, f0) to scan and clean the selected area line by line.

[0038] Real-time data synchronous acquisition: At each instant of laser pulse action, the plasma spectral sensor (320) is synchronously triggered to acquire the plasma spectrum generated by the current pulse. The CCD camera (310) continuously captures images of the cleaning area at a rate of 60 frames per second.

[0039] Real-time spectral analysis and status determination (core closed loop): The signal analysis module (420) of the central processing controller (400) processes each real-time spectrum.

[0040] Extract the peak intensity: Calculate the integrated intensities \(I_{coat}\) and \(I_{sub}\) of the characteristic peaks of the paint layer (such as CN 388.3 nm) and the substrate (such as C247.8 nm) in the real-time spectrum. Calculate the determination ratio \(R\): \(R = I_{coat} / (I_{coat}+I_{sub})\). This ratio reflects the "mixing" degree of the coating and the substrate in the currently ablated material.

[0041] Logical judgment: If \(R\geq0.7\), it is determined as the "safe cleaning state", that is, the laser mainly acts on the paint layer. The adaptive control module (410) may output an instruction to slightly increase the power to 10 W within the allowable range to optimize the cleaning efficiency; if \(0.3 < R < 0.7\), it is determined as the "transition state", that is, it may clean to the interface between the paint layer and the substrate. The adaptive control module (410) instructs the laser to maintain the current parameters and closely monitor; if \(R\leq0.3\), it is determined as the "substrate exposure dangerous state", that is, the spectral signal shows that the substrate component has become dominant. This is the most critical control trigger point.

[0042] Adaptive control response: When the system determines the "substrate exposure dangerous state", the adaptive control module (410) responds within less than 1 millisecond and issues the following instruction combination to the laser generating unit (100) and the beam scanning unit (200): Sudden drop in laser power: Immediately switch the average laser power at the current action point from 10 W to the preset safe power \(P_{safe}=2W\); Increase in scanning speed: Instruct the galvanometer to temporarily increase the speed to 1500 mm / s at the subsequent adjacent scanning points to quickly pass through this sensitive area. At the same time, the CCD vision sensor (310) captures that the color of this point changes from the green of the paint layer to the dark black of the CFRP substrate, which corroborates the spectral judgment result and further confirms the correctness of the control decision.

[0043] Loop and completion: The above process (S2 - S4) is cycled at every moment and each laser action point during cleaning. The system is like an intelligent surgeon with "tactile sense", which can efficiently remove the paint layer and immediately "reduce force" or "move away" once it "feels" that it touches the substrate. Finally, when the entire preset area is scanned and the system no longer records the "dangerous state" that requires a sudden drop in power, the cleaning process automatically ends.

[0044] Verification of cleaning effect: After cleaning, the workpiece is inspected.

[0045] Through visual and microscopic observation, the old paint layer on the workpiece surface is completely removed, revealing the uniform CFRP substrate texture. After inspection with a 100 - fold optical microscope, there are no visible ablation pits, carbonized points or thermal cracks on the substrate surface.

[0046] Surface profilometer measurement: The surface roughness (Ra) of the cleaned area is basically the same as that of the uncleaned original substrate area, indicating that the cleaning process did not cause macroscopic mechanical damage to the substrate.

[0047] Pull-out adhesion test: The adhesion test was conducted on the newly sprayed paint layer. The result reached the highest level, proving that the substrate surface was in good condition and that the interface performance was not degraded due to the cleaning process.

[0048] This embodiment fully demonstrates the effectiveness of the laser precision cleaning method and system provided by the present invention. By using real-time closed-loop feedback control based on plasma spectroscopy, the contradiction between "removing the coating" and "protecting the substrate" in laser cleaning of composite materials is successfully resolved, achieving truly high-precision, non-destructive, and intelligent cleaning, and providing a reliable process solution for the maintenance and remanufacturing of high-end composite materials.

[0049] This invention relates to a laser precision cleaning method and system for composite material surfaces, applicable to fields with extremely high maintenance requirements for composite materials, such as aerospace, high-end sports equipment, and wind turbine blades. Through real-time feedback from plasma spectroscopy, the laser action can be rapidly adjusted or stopped the instant the cleaning reaches the substrate. Furthermore, this invention can automatically adjust laser parameters based on real-time changes in material composition during the cleaning process, adapting to coatings of different thicknesses and aging levels, achieving identification and differentiation between the "coating" and the "substrate," thereby enabling precise selective cleaning. This invention provides a laser precision cleaning method and system for composite material surfaces.

[0050] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may utilize the disclosed technical content to make changes or equivalent variations to other fields. However, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, shall still fall within the protection scope of the present invention. In the description of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" 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. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood through specific circumstances.

Claims

1. A laser precision cleaning system for composite material surfaces, characterized in that, The system includes a laser generating unit, a beam scanning and focusing unit, a real-time monitoring and feedback unit, and a central processing controller. The laser generating unit generates pulsed laser light for cleaning. The beam scanning and focusing unit controls the laser beam to scan the workpiece surface. The real-time monitoring and feedback unit includes a CCD vision sensor and a plasma spectral sensor. The CCD vision sensor acquires image information of the cleaning area, and the plasma spectral sensor analyzes the characteristic spectrum generated by the plasma-excited material. The central processing controller receives the plasma spectrum and image information, identifies the composition of the treated material in real time, and sends laser parameter adjustment commands to the laser generating unit and the beam scanning and focusing unit.

2. The laser precision cleaning method and system for composite material surfaces as described in claim 1, characterized in that, The beam scanning and focusing unit includes a galvanometer and an F-θ lens. The galvanometer and the F-θ lens are used to control the laser beam to scan a predetermined trajectory on the surface of the workpiece and keep the focal point on the cleaning surface.

3. The laser precision cleaning method and system for composite material surfaces as described in claim 1, characterized in that, The plasma spectral sensor employs an optical fiber probe, which is positioned near the exit of the galvanometer. The acquisition end of the plasma spectral sensor is pointed towards the center region of the plasma plume to optimize signal acquisition efficiency and avoid direct laser damage.

4. The laser precision cleaning method and system for composite material surfaces as described in claim 1, characterized in that: The central processing controller includes an adaptive control module and an information analysis module. The information analysis module is used to compare the real-time acquired plasma spectrum with the pre-stored coating characteristic spectrum and substrate characteristic spectrum to determine whether the current laser target is a coating or a substrate. The adaptive control module is used when the current target is determined to be a coating or a substrate. If the current target is determined to be a coating, the first laser parameter set is maintained or optimized. The first laser parameter set is a combination of laser parameters used to effectively remove the coating. If the target of the current action is determined to be the substrate, switch to the second laser parameter set whose energy density does not exceed 30% of the energy density corresponding to the first laser parameter set, or stop the laser output to that point.

5. The laser precision cleaning method and system for composite material surfaces as described in claim 1, characterized in that: The wavelength of the pulsed laser generated by the laser generating unit is 355nm-1064nm, and the pulse width generated by the laser generating unit is on the order of nanoseconds, picoseconds, or femtoseconds.

6. A cleaning method for a laser precision cleaning system for composite material surfaces as described in any one of claims 1-5, characterized in that: Includes the following steps: S1: Based on the known physicochemical properties of the composite material and coating to be cleaned, preset the initial laser parameters and the spectral feature database for material identification; S2: The laser is activated to scan and clean the surface of the composite material. The laser beam scans the cleaning area along a preset trajectory, and the plasma spectral sensor and CCD vision sensor begin to collect data synchronously. The composite material is preferably a carbon fiber reinforced resin matrix composite or fiberglass. S3: The central processing controller compares the real-time plasma spectrum with the characteristic spectra in the database to identify whether the material being ablated by the laser is a coating or a composite matrix. S4: Based on the identification results, adjust the laser power, scanning speed, or on / off status in real time to ensure that damage to the substrate is avoided while removing the coating. "Adjusting laser parameters in real time based on identification results" specifically means: when the characteristic spectrum of the coating is identified, maintain the current parameters; when the characteristic spectrum of the substrate is identified, immediately reduce the laser power and / or increase the scanning speed.

7. The cleaning method of the laser precision cleaning system for composite material surfaces as described in claim 6, characterized in that: In step S2, during the process of scanning and cleaning the surface of the composite material with a laser, images of the cleaning area are simultaneously acquired, and the image color and morphology change information are fused with the plasma spectral analysis results to improve the accuracy of state recognition.

Images