Low-damage CFRP laser drilling device and method based on dynamic multi-mode light beam regulation

Abstract

This invention provides a low-damage CFRP laser drilling device and method based on dynamic multimode beam control. The CFRP laser drilling device includes an ultrafast laser source, a dynamic light field control module, a dual-pulse control module, a galvanometer scanning module, a motion module, and a controller module. The ultrafast laser source, dynamic light field control module, dual-pulse control module, and galvanometer scanning module are arranged on the same optical path. The motion module carries the workpiece to be processed. The controller module is connected to the ultrafast laser source, dynamic light field control module, dual-pulse control module, galvanometer scanning module, and motion module. This invention can achieve precise control of energy density within the microsecond time domain and micrometer spatial domain to achieve the fabrication of CFRP micropore structures with low thermal impact, high consistency, and high geometric accuracy, effectively improving the stability and reliability of the processing to meet the needs of micropore precision machining in aerospace and precision manufacturing fields.

Description

Technical Field

[0001] This invention relates in particular to a low-damage CFRP laser drilling device and method based on dynamic multimode beam control, belonging to the field of carbon fiber reinforced resin matrix composite (CFRP) processing technology. Background Technology

[0002] Carbon fiber reinforced polymer (CFRP) has become an important manufacturing material for aerospace, automotive lightweighting, and high-end equipment structural components due to its high specific strength, high specific stiffness, excellent fatigue resistance, and corrosion resistance. With the continuous advancement of lightweighting and increasing complexity of structural components, the demand for precision through-holes, assembly holes, and micro-structured holes in CFRP components has increased significantly, placing higher requirements on processing quality and geometric consistency. However, CFRP is a typical anisotropic composite material, composed of high-modulus carbon fibers and a low-thermal-conductivity resin matrix through a layup process. The significant differences between carbon fibers and resin in optical absorptivity, thermal conductivity, coefficient of thermal expansion, and mechanical response lead to uneven heat absorption and stress response under laser irradiation. This makes it difficult for heat to be uniformly transferred between the fibers and the matrix during processing, resulting in localized heat accumulation, expansion of the heat-affected zone (HAZ), carbonization of the matrix resin, fiber pull-out, and interfacial delamination. Meanwhile, since the thermal decomposition temperature of the resin matrix is ​​much lower than the sublimation temperature of carbon fiber, high-temperature zones are easily formed under the action of laser energy, leading to melting, carbonization and structural degradation of the hole wall surface, which in turn affects the hole shape accuracy and structural integrity.

[0003] Existing CFRP laser drilling technologies primarily employ fixed Gaussian beams or single-pulse output modes. These methods typically maintain constant beam energy distribution and pulse timing, lacking the ability to adapt to the differences in thermal response between carbon fiber and resin layers in multilayer CFRP structures. Furthermore, due to significant differences in the layup angles, thicknesses, and fiber volume fractions across different CFRP layers, fixed-mode energy transfer struggles to meet the thermal balance requirements of complex interfaces, often resulting in larger hole taper, increased surface roughness, and reduced processing consistency. Some technical solutions attempt to reduce thermal damage through pulse energy adjustment or gas-assisted cooling, but these remain limited by the immutability of beam morphology and the complexity of energy timing coupling, making it difficult to solve the problems of heat-affected zone control and hole wall quality uniformity.

[0004] In related patents and research, scholars and institutions have explored improvements to laser processing of composite materials. For example, CN115194953A proposes a laser-assisted micro-drilling device and method for hard, brittle, and transparent materials, which improves the integrity of the hole walls in hard and brittle materials through a laser-mechanical composite approach. However, this technology relies on mechanical tools to remove material, making it difficult to achieve high-precision non-contact processing of CFRP. CN105499811A discloses a ring-shaped composite pulse laser drilling method and device, which improves the spatial distribution of energy by adjusting the long pulse width. However, its beam morphology is still a fixed Gaussian distribution, making it difficult to dynamically adapt to fiber-matrix structures with different layup directions. In addition, some studies have explored helical scanning paths, zoned energy distribution, and ultrashort pulse technology to reduce the heat-affected zone. However, the control of these methods mainly focuses on the macroscopic process parameters. The synergistic mechanism of energy density and pulse timing at the microscopic scale still needs to be further elucidated, and there is a lack of a dynamic feedback system that can respond in real time to the thermo-mechanical coupling behavior of materials.

[0005] In summary, existing CFRP laser drilling technology still has significant limitations in terms of beam spatial distribution adjustment, energy timing control, and coordination of the thermo-mechanical response of multilayer structures. A beam output with a fixed morphology cannot effectively match the optical and thermophysical properties of the various layers within the CFRP. The energy transfer path is greatly affected by fiber orientation and interlayer structure, easily leading to concentrated thermal damage and hole shape deviations. Existing processing strategies lack dynamic control over energy timing and spatial distribution, making it difficult to achieve stable energy coupling and thermal stress distribution control during processing, thus limiting the fabrication of high-quality, low-thermal-damage holes. Summary of the Invention

[0006] The main objective of this invention is to provide a low-damage CFRP laser drilling device and method based on dynamic multimode beam control. During the laser drilling process, the beam shape and energy timing are adaptively controlled to coordinate the thermo-mechanical response of the multilayer structure of CFRP material. This achieves high-efficiency laser processing with high hole shape accuracy, low thermal damage, and excellent processing consistency, meeting the precision manufacturing requirements of high-performance composite material components and overcoming the shortcomings of the prior art.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0008] The first aspect of this invention provides a low-damage CFRP laser drilling device based on dynamic multimode beam modulation, comprising:

[0009] An ultrafast laser source is used to provide the initial laser beam;

[0010] A dynamic optical field modulation module is disposed in the optical path of the initial laser beam and is used to dynamically modulate the phase or amplitude distribution of the initial laser beam, so that the optical field mode of the initial laser beam switches between multiple preset modes to form a modulated laser beam.

[0011] A dual-pulse control module is disposed in the optical path of the modulated laser beam and is used to modulate the modulated laser beam into a dual-pulse sequence with a preset energy difference and a preset time interval to form a controllable laser beam. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than the energy density of the stripping pulse.

[0012] A galvanometer scanning module is disposed in the optical path of the control laser beam, and is used to focus the control laser beam to form a processing laser beam, and to scan and process the workpiece with the processing laser beam according to a preset scanning trajectory;

[0013] A motion module is used to carry the workpiece and drive the processing laser beam to move relative to the workpiece along the axial direction of the micro-hole structure formed during processing.

[0014] The controller module is connected to the ultrafast laser source, the dynamic light field control module, the dual-pulse control module, the galvanometer scanning module, and the motion module, respectively.

[0015] Furthermore, the initial laser beam is a picosecond or femtosecond pulsed laser beam with a wavelength of 1020 nm to 1070 nm, a pulse width of 100 fs to 10 ps, ​​a repetition frequency of 100 kHz to 2 MHz, and a power of 0.1 W to 30 W.

[0016] Furthermore, the dynamic light field modulation module includes a spatial light modulator (SLM) or a digital micromirror array (DMD), and the light field mode includes a Gaussian mode, a vortex mode, and a flat-top mode. The switching rate of the light field mode does not exceed 1 ms, which means that the switching rate is greater than 0.

[0017] Furthermore, the energy density of the preheating pulse is 0.15 J / cm² to 0.35 J / cm², the energy density of the stripping pulse is 0.35 J / cm² to 0.85 J / cm², and the time interval Δt of the dual pulse sequence is 5 μs to 20 μs.

[0018] Furthermore, the motion module includes a three-axis linkage platform, which is used to carry the workpiece and drive the workpiece to move along the x-axis, y-axis and z-axis of a three-dimensional coordinate system, wherein the z-axis direction is parallel to the axial direction of the microporous structure.

[0019] In a more specific implementation, the low-damage CFRP laser drilling device based on dynamic multimode beam modulation further includes:

[0020] The online monitoring module is used to collect temperature signals and scattered light intensity signals of the workpiece's processing area in real time;

[0021] The controller module is also connected to the online monitoring module, and the controller module obtains the temperature deviation based on the comparison of the collected signal with a preset threshold. and scattered light deviation It employs a pre-defined optimization algorithm as the core solver, minimizing the objective function. J To obtain the optimal control law mapping function with the objective of minimizing processing defects. F Based on the optimal control law mapping function F The laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process.

[0022] The objective function of the optimization algorithm is:

[0023] ;

[0024] W HAZ The width of the heat-affected zone. I For the taper of the hole wall, For the thickness of the redeposition layer, a:b:c This represents the weighting coefficient ratio. a:b:c =2:2:1;

[0025] The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output is laser power. P Light field mode M Double pulse sequence interval D t and axial step distance D z; based on the objective function J The evaluation or predicted value is obtained by the optimization algorithm, which iteratively updates the mapping relationship between laser energy input and workpiece material response through the optimal control law mapping function. F Generate the first k+1 Optimal processing parameter set for each sampling control cycle ;

[0026] ;

[0027] in, k Indicates the current numberk One sampling control cycle; {P,M,Δt,Δz} k Indicates the first k Laser power, optical field mode, time interval of the double pulse sequence, and axial step distance for each sampling control cycle; ΔT k Indicates the first k Temperature deviation detected in each sampling control cycle ΔS k Indicates the first k The scattered light deviation detected in each sampling control cycle, and the optimal control law mapping function. F This represents a nonlinear mapping model constructed by an optimization algorithm, whose internal parameters are determined by the objective function. J The gradient descent direction is adjusted in real time to ensure that the output processing parameters can converge the processing in the direction of minimizing defects.

[0028] Furthermore, the online monitoring module includes an infrared temperature measurement mechanism and a scattered light detection mechanism. The infrared temperature measurement mechanism is used to collect temperature signals generated during the processing, and the scattered light detection mechanism is used to collect scattered light intensity signals generated during the processing.

[0029] Furthermore, the infrared temperature measurement mechanism has a temperature measurement band of 3 μm to 5 μm, and the infrared temperature measurement mechanism and the scattered light detection mechanism have a collection frequency of 1 kHz to 5 kHz.

[0030] In a more specific implementation, the low-damage CFRP laser drilling device based on dynamic multimode beam modulation further includes:

[0031] A gas-assisted module is provided, which is used to spray protective gas into the processing area of ​​the workpiece. The gas-assisted module is also connected to the controller module.

[0032] Furthermore, the spraying distance between the gas-assisted module and the processing area on the workpiece surface is 5 μm to 30 μm, and the spraying angle is 20° to 40°.

[0033] A second aspect of this invention provides a low-damage CFRP laser drilling method based on dynamic multimode beam modulation, comprising:

[0034] An initial laser beam is provided by an ultrafast laser source, and the phase or amplitude distribution of the initial laser beam is dynamically modulated by a dynamic optical field control module, so that the optical field mode of the initial laser beam switches between multiple preset modes to form a modulated laser beam.

[0035] The modulated laser beam is modulated into a dual-pulse sequence with a preset energy difference and a preset time interval using a dual-pulse control module, thereby forming and outputting the controlled laser beam. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than that of the stripping pulse.

[0036] The control laser beam is focused by the galvanometer scanning module to form a processing laser beam, and the processing laser beam is used to scan and process the workpiece according to a preset scanning trajectory to form a micro-hole structure;

[0037] Furthermore, the processing laser beam is driven by a motion module to generate relative motion with the workpiece along the axial direction of the microporous structure, wherein the workpiece is a carbon fiber reinforced composite material.

[0038] Furthermore, the initial laser beam is a picosecond or femtosecond pulsed laser beam with a wavelength of 1020 nm to 1070 nm, a pulse width of 100 fs to 10 ps, ​​a repetition frequency of 100 kHz to 2 MHz, and a power of 0.1 W to 30 W.

[0039] Furthermore, the dynamic light field modulation module includes a spatial light modulator (SLM) or a digital micromirror array (DMD), the light field mode includes a Gaussian mode, a vortex mode and a flat-top mode, and the switching rate of the light field mode is greater than 0 and does not exceed 1 ms.

[0040] Furthermore, the energy density of the preheating pulse is 0.15 J / cm² to 0.35 J / cm², the energy density of the stripping pulse is 0.35 J / cm² to 0.85 J / cm², and the time interval Δt of the dual pulse sequence is 5 μs to 20 μs.

[0041] Furthermore, the motion module includes a three-axis linkage platform, which is used to carry the workpiece and drive the workpiece to move along the x-axis, y-axis and z-axis of a three-dimensional coordinate system, wherein the z-axis direction is parallel to the axial direction of the microporous structure.

[0042] Furthermore, the preset scanning trajectory is a concentric spiral path with an axial step distance. D z ranges from 5 μm to 30 μm.

[0043] Furthermore, the scanning speed of the processing laser beam is 50 mm / s to 500 mm / s.

[0044] In a more specific implementation, the low-damage CFRP laser drilling method based on dynamic multimode beam modulation further includes:

[0045] The online monitoring module collects the temperature signal and scattered light intensity signal of the workpiece's processing area in real time.

[0046] The controller module compares the signal collected by the online monitoring module with a preset threshold to obtain the temperature deviation. and scattered light deviation It employs a pre-defined optimization algorithm as the core solver, minimizing the objective function. J To obtain the optimal control law mapping function with the objective of minimizing processing defects. F Based on the optimal control law mapping function F The laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process.

[0047] The objective function of the optimization algorithm is:

[0048] ;

[0049] W HAZ The width of the heat-affected zone. I For the taper of the hole wall, For the thickness of the redeposition layer, a:b:c This represents the weighting coefficient ratio. a:b:c =2:2:1;

[0050] The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output is laser power. P Light field mode M Double pulse sequence interval D t and axial step distance D z; based on the objective function J The evaluation or predicted value is obtained by the optimization algorithm, which iteratively updates the mapping relationship between laser energy input and workpiece material response through the optimal control law mapping function. F Generate the first k+1 Optimal processing parameter set for each sampling control cycle ;

[0051] ;

[0052] in, k Indicates the current number k One sampling control cycle; {P,M,Δt,Δz} k Indicates the first k Laser power, optical field mode, time interval of the double pulse sequence, and axial step distance for each sampling control cycle; ΔT k Indicates the first kTemperature deviation detected in each sampling control cycle ΔS k Indicates the first k The scattered light deviation detected in each sampling control cycle, and the optimal control law mapping function. F This represents a nonlinear mapping model constructed by an optimization algorithm, whose internal parameters are determined by the objective function. J The gradient descent direction is adjusted in real time to ensure that the output processing parameters can converge the processing in the direction of minimizing defects.

[0053] Furthermore, the online monitoring module includes an infrared temperature measurement mechanism and a scattered light detection mechanism. The infrared temperature measurement mechanism is used to collect temperature signals generated during the processing, and the scattered light detection mechanism is used to collect scattered light intensity signals generated during the processing.

[0054] Furthermore, the infrared temperature measurement mechanism has a temperature measurement band of 3 μm to 5 μm, and the infrared temperature measurement mechanism and the scattered light detection mechanism have a collection frequency of 1 kHz to 5 kHz.

[0055] In a more specific implementation, the low-damage CFRP laser drilling method based on dynamic multimode beam modulation further includes:

[0056] During the scanning and processing of the workpiece using a processing laser beam, a gas-assisted module sprays protective gas onto the processing area on the workpiece surface.

[0057] Furthermore, the spraying distance between the gas-assisted module and the processing area on the workpiece surface is 5 μm to 30 μm, the spraying angle is 20° to 40°, and the spraying flow rate is 30 L / min to 80 L / min.

[0058] Furthermore, the protective gas is an inert gas.

[0059] Furthermore, the low-damage CFRP laser drilling method based on dynamic multimode beam control is implemented based on the low-damage CFRP laser drilling device based on dynamic multimode beam control.

[0060] A third aspect of this invention provides a laser processing control method for the low-damage CFRP laser drilling device based on dynamic multimode beam control or the low-damage CFRP laser drilling method based on dynamic multimode beam control.

[0061] It includes:

[0062] Temperature and scattered light intensity signals are collected during laser processing. The collected temperature and scattered light intensity signals are compared with preset thresholds to obtain the temperature deviation. and scattered light deviation It employs a pre-defined optimization algorithm as the core solver, minimizing the objective function. J To obtain the optimal control law mapping function with the objective of minimizing processing defects. F Based on the optimal control law mapping function F The laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process.

[0063] The objective function of the optimization algorithm is:

[0064] ;

[0065] W HAZ The width of the heat-affected zone. I For the taper of the hole wall, For the thickness of the redeposition layer, a:b:c This represents the weighting coefficient ratio. a:b:c =2:2:1;

[0066] The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output is laser power. P Light field mode M Double pulse sequence interval D t and axial step distance D z; based on the objective function J The evaluation or predicted value is obtained by the optimization algorithm, which iteratively updates the mapping relationship between laser energy input and workpiece material response through the optimal control law mapping function. F Generate the first k+1 Optimal processing parameter set for each sampling control cycle ;

[0067] ;

[0068] in, k Indicates the current number k One sampling control cycle; {P,M,Δt,Δz} k Indicates the first k Laser power, optical field mode, time interval of the double pulse sequence, and axial step distance for each sampling control cycle; ΔT k Indicates the first k Temperature deviation detected in each sampling control cycle ΔS k Indicates the first kThe scattered light deviation detected in each sampling control cycle, and the optimal control law mapping function. F This represents a nonlinear mapping model constructed by an optimization algorithm, whose internal parameters are determined by the objective function. J The gradient descent direction is adjusted in real time to ensure that the output processing parameters can converge the processing in the direction of minimizing defects.

[0069] Compared with the prior art, the advantages of the present invention include:

[0070] This invention achieves coordinated optimization of laser energy distribution in the temporal and spatial domains through dynamic multimode beam modulation and dual-pulse energy coupling, effectively improving thermal damage to the hole wall and morphological consistency.

[0071] This invention employs programmable optical field control technology to rapidly switch laser energy between Gaussian, vortex, and flat-top optical fields, thereby obtaining a more uniform energy distribution, which reduces the taper of the hole wall and avoids local overheating. Furthermore, through a dual-pulse "preheat-stripping" sequence, it achieves efficient material removal under low heat input, significantly reducing the width of the heat-affected zone and interface delamination.

[0072] This invention achieves real-time adaptive energy adjustment during processing by combining a multi-parameter closed-loop feedback control system with infrared temperature measurement and scattered light monitoring, effectively improving the accuracy of aperture size and morphology. At the same time, the side spraying of inert gas further reduces heat accumulation and prevents molten material redeposition. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the overall structure of a CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling, provided in a typical embodiment of the present invention.

[0074] Figure 2 This is a schematic diagram of the closed-loop control logic and feedback signal flow of a CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling, provided in a typical embodiment of the present invention.

[0075] Figure 3 This is a schematic diagram illustrating the effect of beam mode variation on energy distribution in a typical embodiment of the present invention;

[0076] Figure 4 This is a schematic diagram of dual-pulse timing control based on dynamic multimode beam modulation in a typical embodiment of the present invention;

[0077] Figure 5 This is a schematic diagram of the cross-section of CFRP perforation under different control strategies in a typical embodiment of the present invention. Detailed Implementation

[0078] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate the technical solution, its implementation process, and its principles.

[0079] Terminology Explanation: Redeposit layer. In laser processing (for heterogeneous materials such as CFRP), some material is melted or vaporized by laser bombardment, but fails to be completely blown away from the processing area by the auxiliary gas. Instead, it is re-solidified / deposited on the surface of the processing area or the surrounding surface to form an adhesion layer. This adhesion layer is called the redeposit layer.

[0080] This invention addresses the shortcomings of existing CFRP laser drilling processes, which often employ fixed Gaussian beams or single-pulse processing schemes. These schemes suffer from poor processing stability and low hole shape consistency due to the inability of energy spatial distribution and pulse timing to adapt to the differences in thermal-mechanical response within the multilayered CFRP structure. The invention provides a low-damage CFRP laser drilling device and method based on dynamic multimode beam control. This method enables spatiotemporal programmable control of laser energy density. By dynamically adjusting the light field mode and pulse energy timing, it effectively suppresses heat accumulation and delamination defects, improves hole wall morphology consistency and processing quality, thereby obtaining a highly consistent, low-damage CFRP microporous structure.

[0081] The following will further explain the technical solution, its implementation process and principle in conjunction with the accompanying drawings and specific implementation examples. Unless otherwise specified, the lasers, spatial light modulators (SLMs) or digital micromirror arrays (DMDs), scanning galvanometers and other optical components, three-axis linkage platforms and other components involved in the embodiments of the present invention are all known in the art, and their specific structures and equipment models are not limited here.

[0082] In a more typical implementation scheme, please refer to Figure 1 A CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling includes an ultrafast laser source 1, a dynamic light field modulation module 3 (also known as a spatial light modulation module, hereinafter the same), a dual-pulse modulation module 5, a galvanometer scanning module 7, a motion module 10, and a controller module. The ultrafast laser source 1, the dynamic light field modulation module 3, the dual-pulse modulation module 5, and the galvanometer scanning module 7 are arranged on the same optical path. The motion module 10 is used to carry the workpiece to be processed. The controller module is connected to the ultrafast laser source 1, the dynamic light field modulation module 3, the dual-pulse modulation module 5, the galvanometer scanning module 7, and the motion module 10 respectively.

[0083] Among them, the ultrafast laser source 1 is used to provide an initial laser beam 2 with a high repetition frequency. The dynamic optical field control module 3, the dual pulse control module 5, and the galvanometer scanning module 7 are sequentially arranged in the optical path of the initial laser beam 2. The initial laser beam 2 is modulated into a modulated laser beam 4 by the dynamic optical field control module 3. The modulated laser beam 4 is modulated into a controlled laser beam 6 by the dual pulse control module 5. The controlled laser beam 6 is focused by the galvanometer scanning module 7 to form a processing laser beam 8, which is then irradiated onto the processing area on the surface of the workpiece (specifically, the CFRP workpiece) located on the motion module 10, thereby forming a microporous structure on the surface of the workpiece.

[0084] Specifically, the ultrafast laser source 1 is a picosecond or femtosecond pulsed laser, and the initial laser beam 2 is a picosecond or femtosecond pulsed laser beam. The wavelength of the initial laser beam is 1020 nm to 1070 nm, the pulse width is 100 fs to 10 ps, ​​and the repetition frequency is 100 kHz to 2 MHz to ensure that the single pulse energy is low and the average power is controllable, thereby realizing the removal of non-thermal micro-area materials. Specifically, the power of the initial laser beam is 0.1 W to 30 W.

[0085] Specifically, the dynamic light field modulation module 3 is disposed on the optical path of the initial laser beam 2, and is used to dynamically modulate the phase or amplitude distribution of the initial laser beam 2, so that the light field mode of the initial laser beam 2 switches between multiple preset modes to form a modulated laser beam 4. Specifically, the dynamic light field modulation module 3 includes a spatial light modulator (SLM) or a digital micromirror array (DMD), which can modulate the phase or amplitude distribution of the initial laser beam 2 in real time, so that the light field mode switches between multiple modes such as Gaussian, vortex, and flat-top, with a switching rate not exceeding 1 ms. The energy distribution in Gaussian mode, vortex mode, and flat-top mode is as follows: Figure 3 As shown, this control method can dynamically match the energy distribution based on the differences in fiber orientation and matrix thermophysical properties in the multilayer structure of the CFRP workpiece, achieving spatial adaptive energy coupling.

[0086] Specifically, the dual-pulse control module 5 is disposed in the optical path of the modulated laser beam 4, and is used to modulate the modulated laser beam 4 into a dual-pulse sequence with a preset energy difference and a preset time interval to form a controllable laser beam 6. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than that of the stripping pulse. More specifically, the energy density of the preheating pulse is 0.15 J / cm² to 0.35 J / cm², mainly used to soften or vaporize the resin matrix and induce interfacial thermal stress relaxation. The energy density of the stripping pulse is 0.35 J / cm² to 0.85 J / cm², used to achieve efficient stripping and material removal. The time interval Δt of the dual-pulse sequence is 5 μs to 20 μs. By reasonably setting the time interval, excessive energy superposition can be effectively avoided to prevent heat accumulation, thereby ensuring the stability and controllability of the material removal process.

[0087] For example, the dual-pulse control module 5 is an electronic module for generating and controlling dual-pulse signals. It is a specialized "electronic control system" or "signal generator" that integrates a high-precision clock, high-speed logic and delay circuit. It can accept a command and output two trigger pulses that are precisely controllable in time, similar to a dual-pulse signal generator. It is a conventional device known in the art, and its working principle will not be described in detail here, nor will its specific model be limited.

[0088] Specifically, the galvanometer scanning module 7 is disposed in the optical path of the controlled laser beam 6, and is used to focus the controlled laser beam 6 to form a processing laser beam 8, and to scan and process the workpiece with the processing laser beam 8 according to a preset scanning trajectory. Specifically, it is basically the same as conventional structures known in the art. The scanning galvanometer module includes a scanning galvanometer and a focusing lens, etc. The controlled laser beam 6 is reflected by the scanning galvanometer and then incident on the focusing lens, and is focused on the surface of the workpiece by the focusing lens. The structure and working principle of the galvanometer scanning module 7 are known in the art and are not specifically limited here.

[0089] Specifically, the motion module 10 is used to support and position the workpiece, and at least drive / move the workpiece to generate relative motion along the axial direction of the machined microporous structure. More specifically, the motion module 10 can be a three-axis linkage motion platform, which can drive the workpiece to move along the x-axis, y-axis, and z-axis of a three-dimensional coordinate system, wherein the z-axis direction is parallel to the axial direction of the microporous structure. It should be noted that the structure and motion mode of this three-axis linkage platform are known in the art, and the three-axis linkage platform can fix the workpiece on itself; the specific fixing structure and fixing method are not limited.

[0090] Please refer to it again. Figure 1In a preferred embodiment, the CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling further includes a gas-assisted module 9, which is also connected to the controller module. The gas-assisted module 9 is used to spray protective gas onto the processing area of ​​the workpiece. Specifically, the gas-assisted module 9 is positioned diagonally above the workpiece, with its nozzle facing the processing area of ​​the workpiece.

[0091] To further achieve adaptive energy control, please refer again. Figure 1 The CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling also includes an online monitoring module. This module is used to collect the temperature signal (i.e., thermal radiation signal) and scattered light intensity signal (i.e., plasma scattering signal) of the workpiece's processing area in real time during laser processing. The online monitoring module is connected to a controller module, which obtains the temperature deviation by comparing the collected signals (i.e., temperature signal and scattered light intensity signal) with a preset threshold. and scattered light deviation It employs a pre-defined optimization algorithm as the core solver, minimizing the objective function. J To obtain the optimal control law mapping function with the objective of minimizing processing defects. F Based on the optimal control law mapping function F The laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing.

[0092] Specifically, the online monitoring module includes an infrared temperature measurement mechanism 11 and a scattered light detection mechanism 12. The infrared temperature measurement mechanism 11 is used to collect temperature signals generated during the processing, and the scattered light detection mechanism 12 is used to collect scattered light intensity signals generated during the processing. The infrared temperature measurement mechanism 11 has a temperature measurement band of 3 μm to 5 μm, and the infrared temperature measurement mechanism 11 and the scattered light detection mechanism 12 have a sampling frequency of 1 kHz to 5 kHz.

[0093] Specifically, the controller module includes a multi-parameter closed-loop control system 13 (which may employ a field-programmable gate array (FPGA) or a system-on-a-chip (SoC) architecture, as is known in the art) and an industrial computer (as is known in the art and can be commercially available) 14. The multi-parameter closed-loop control system 13 is electrically connected to the industrial computer 14, the ultrafast laser source 1, the dynamic light field modulation module 3, the dual-pulse modulation module 5, the galvanometer scanning module 7, the motion module 10, and the online monitoring module. The multi-parameter closed-loop control system 13 receives feedback signals from the online monitoring module and, based on its built-in optimization algorithm (such as... Figure 2As shown, the operating parameters of each functional module are adjusted in real time. For example, the communication between the multi-parameter closed-loop control system 13 and the online monitoring module can adopt a high-performance industrial fieldbus system based on Ethernet (EtherCAT) or a high-speed serial bus to ensure real-time feedback control.

[0094] Specifically, the objective function of the optimization algorithm is:

[0095] ;

[0096] W HAZ The width of the heat-affected zone. I For the taper of the hole wall, For the thickness of the redeposition layer, a:b:c This represents the weighting coefficient ratio. a:b:c =2:2:1;

[0097] The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output is laser power. P Light field mode M Double pulse sequence interval D t and axial step distance D z; based on the objective function J The evaluation or predicted value is obtained by the optimization algorithm, which iteratively updates the mapping relationship between laser energy input and workpiece material response through the optimal control law mapping function. F Generate the first k+1 Optimal processing parameter set for each sampling control cycle ;

[0098] ;

[0099] in, k Indicates the current number k One sampling control cycle; {P,M,Δt,Δz} k Indicates the first k Laser power, optical field mode, time interval of the double pulse sequence, and axial step distance for each sampling control cycle; ΔT k Indicates the first k Temperature deviation detected in each sampling control cycle ΔS k Indicates the first k The scattered light deviation detected in each sampling control cycle, and the optimal control law mapping function. F This represents a nonlinear mapping model constructed by an optimization algorithm, whose internal parameters are determined by the objective function.J The gradient descent direction is adjusted in real time to ensure that the output processing parameters can converge the processing in the direction of minimizing defects.

[0100] Please refer to a typical implementation plan as well. Figure 1 and Figure 2 A method for laser drilling of CFRP based on dynamic multimode beam modulation and dual-pulse energy coupling, based on Figure 1 The embodiment of a CFRP laser drilling device based on dynamic multimode beam modulation and dual-pulse energy coupling shown in the figure specifically includes:

[0101] The workpiece is placed on the motion module 10, and an initial laser beam is provided by the ultrafast laser source 1. This initial laser beam sequentially passes through the dynamic light field control module 3, the dual-pulse control module 5, and the galvanometer scanning module 7 to form a processing beam 8, which is then incident on the processing area of ​​the workpiece surface located on the motion module 10. The galvanometer scanning module 7 causes the processing beam 8 to scan and process the workpiece along a preset scanning trajectory, forming a micropore structure. Specifically, the scanning trajectory can be a concentric spiral path with an axial step distance. D z ranges from 5 μm to 30 μm, and the scanning speed ranges from 50 mm / s to 500 mm / s.

[0102] Specifically, the dynamic light field modulation module 3 dynamically modulates the phase or amplitude distribution of the initial laser beam 2, causing the light field mode of the initial laser beam 2 to switch between multiple preset modes to form a modulated laser beam 4. Specifically, the dynamic light field modulation module 3 includes a spatial light modulator (SLM) or a digital micromirror array (DMD), which can modulate the phase or amplitude distribution of the initial laser beam 2 in real time, causing the light field mode to switch between multiple modes such as Gaussian, vortex, and flat-top, with a switching rate greater than 0 and not exceeding 1 ms.

[0103] Specifically, the energy distribution in the Gaussian mode, vortex mode, and flat-top mode is as follows: Figure 3 As shown, the dynamic light field control module 3 can achieve energy distribution under different light field modes. Traditional Gaussian beams exhibit a center-edge normal energy distribution, which can easily lead to energy overshoot and heat accumulation in the central region during CFRP workpiece processing, while insufficient energy in the edge region results in conical holes and significant thermal damage. This invention dynamically switches the beam to a vortex beam or a flat-top beam using the dynamic light field control module 3. The vortex beam has a hollow, ring-shaped energy distribution, suitable for circumferential cutting or removing hole wall material. The flat-top beam has a uniform energy distribution within the beam spot, suitable for layer-by-layer peeling removal. This ability to dynamically match the light field mode according to the CFRP material characteristics (such as fiber orientation and resin content) and processing depth is key to achieving precise energy coupling, suppressing thermal damage, and improving hole shape consistency.

[0104] Specifically, the dual-pulse control module 5 modulates the modulated laser beam 4 into a dual-pulse sequence with a preset energy difference and a preset time interval to form the controlled laser beam 6. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than that of the stripping pulse. Dual-pulse timing control based on dynamic multimode beam modulation is as follows: Figure 4 As shown, traditional single-pulse processing, especially at high energies, is prone to defects in CFRP materials such as plasma shielding, spattering, recasting layers, and interface delamination. The dual-pulse sequence used in this invention consists of a low-energy (0.15 J / cm²~0.35 J / cm²) "preheating pulse" and a high-energy (e.g., 0.35 J / cm²~0.85 J / cm²) "stripping pulse," with a microsecond-level time interval between the two pulses. D t( D (t ranges from 5 μs to 20 μs). The "preheating pulse" is applied to the material first to soften or vaporize the resin matrix and induce interfacial thermal stress relaxation; the subsequent "peeling pulse" then removes the material efficiently and with low damage after the material has been "pretreated". By dynamically controlling the pulse timing (in the middle) and switching the beam mode, the accumulation and release of heat in the material can be precisely controlled, achieving optimal synergy between "preheating-peeling", thereby significantly reducing thermal damage and delamination.

[0105] The cross-sectional effect of CFRP perforation under different control strategies is as follows: Figure 5 As shown, traditional single-pulse machining suffers from severe hole wall taper, enlarged heat-affected zone (dark area), and obvious delamination defects due to uneven energy distribution and significant thermal effects. While a dual-pulse strategy, employing a "preheat-stripping" mechanism, significantly suppresses heat-affected zone and delamination, the taper problem persists due to the fixed beam mode (e.g., still a Gaussian beam). This invention's dynamic multimode dual-pulse method synergistically combines dual-pulse timing control and dynamic optical field modulation to address thermal damage, delamination, and hole taper issues. Supplemented by an online monitoring and closed-loop feedback control system, it aims to achieve high-quality machining results with minimized heat-affected zone, no delamination defects, and vertical hole walls (no taper).

[0106] Specifically, during laser processing, this invention also uses a gas-assisted module 9 to spray protective gas onto the processing area of ​​the workpiece. The sprayed protective gas forms a localized cooling and debris removal airflow, achieving localized cooling and efficient removal of processing debris. This effectively reduces local temperature, weakens the expansion of the heat-affected zone, and prevents carbide deposition and secondary absorption effects within the processing area, improving the cleanliness of the pore walls of the microporous structure formed during processing. Specifically, the protective gas is generally an inert gas, such as nitrogen or argon. For example, the spray distance between the nozzle of the gas-assisted module 9 and the processing area on the workpiece surface is 5 μm to 30 μm, the spray angle (the angle between the nozzle's central axis and the surface where the workpiece processing area is located) is 20° to 40°, and the flow rate is 30 L / min to 80 L / min.

[0107] For further information on achieving adaptive energy control, please refer to the following: Figure 1 and Figure 2 During the laser treatment of the workpiece, the laser-material interaction generates temperature signals (i.e., thermal radiation signals) and scattered light intensity signals (i.e., plasma scattering signals). The online monitoring module captures these signals in real time, with a detection wavelength of 3 μm to 5 μm and a sampling frequency of 1 kHz to 5 kHz, and transmits them to the controller module. The controller module compares the collected temperature signals and scattered light intensity signals with preset thresholds to generate a temperature deviation. and scattered light deviation These two deviation signals are input into the optimization algorithm (such as Extreme Learning Machine (ELM) or Bayesian optimization algorithm) built into the controller module. The core of this optimization algorithm is to establish laser-material processing parameters (laser power). P Light field mode M Double pulse sequence interval D t, axial step distance D z) and material response (e.g., width of heat-affected zone) W HAZ Hole wall taper I Surface redeposition thickness The mapping model between () and (). The optimization objective is to minimize the objective function:

[0108] ；

[0109] in, a、b、c This represents the weighting coefficient ratio.

[0110] The controller module, based on the calculation results of the optimization algorithm, uses the control law mapping function. F A new set of optimal control parameters is generated in real time. That is, the first k+1The control parameters for each sampling control cycle are output to various execution modules (ultrafast laser source 1, dynamic light field modulation module 3, dual pulse modulation module 5, galvanometer scanning module 7, motion module 10, etc.), thereby realizing adaptive closed-loop control of the spatiotemporal distribution of laser energy, ensuring the stability of the processing process and the high-quality preparation of the hole.

[0111] Specifically, the online monitoring module has a sampling frequency of 1 kHz to 5 kHz. The controller module performs moving average filtering or downsampling on the high-frequency sampling signal to output stable control commands within the sampling control cycle. Combined with a scanning speed of 50 mm / s to 500 mm / s, it achieves dynamic correction of energy and light field distribution every 50 μm to 500 μm along the scanning trajectory. This spatial resolution effectively covers the structural feature scale of the alternating resin and fiber layers in the CFRP material, thus ensuring the effectiveness and real-time performance of adaptive control.

[0112] Typically, the duration of the sampling control period in this embodiment of the invention can be 0.2 ms to 1 ms. This duration is determined by the mode switching response time of the spatial light modulation module. Within each sampling control period, the controller module calculates the deviation signal based on the average value of sensor data from the past N sampling points and outputs the laser power to maintain the current sampling control period. P Light field mode M Double pulse sequence interval D t, axial step distance D The z command enables timing matching between high-frequency sampling by the sensor and low-frequency response by the actuator.

[0113] Through the synergistic effect of the above-mentioned device structure and process, the present invention can achieve precise control of energy density in the microsecond time domain and micrometer spatial domain to realize the preparation of CFRP microporous structures with low thermal impact, high consistency and high geometric accuracy, effectively improving the stability and reliability of the processing process, so as to meet the microporous precision processing in the aerospace and precision manufacturing fields.

[0114] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A low-damage CFRP laser drilling device based on dynamic multimode beam control, characterized in that, include: An ultrafast laser source is used to provide the initial laser beam; A dynamic optical field modulation module is disposed in the optical path of the initial laser beam and is used to dynamically modulate the phase or amplitude distribution of the initial laser beam, so that the optical field mode of the initial laser beam switches between multiple preset modes to form a modulated laser beam. A dual-pulse control module is disposed in the optical path of the modulated laser beam and is used to modulate the modulated laser beam into a dual-pulse sequence with a preset energy difference and a preset time interval to form a controllable laser beam. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than the energy density of the stripping pulse. A galvanometer scanning module is disposed in the optical path of the control laser beam. It is used to focus the control laser beam to form a processing laser beam, and to scan and process the workpiece with the processing laser beam according to a preset scanning trajectory, at least to process and form a micro-hole structure on the workpiece. A motion module is used to carry the workpiece and drive the processing laser beam to move relative to the workpiece along the axial direction of the micro-hole structure formed during processing. The online monitoring module is used to collect temperature signals and scattered light intensity signals of the workpiece's processing area in real time; The controller module is connected to the ultrafast laser source, the dynamic light field modulation module, the dual-pulse modulation module, the galvanometer scanning module, the motion module, and the online monitoring module, respectively. The controller module obtains the temperature deviation by comparing the collected signal with a preset threshold. and scattered light deviation The system employs a preset optimization algorithm as the core solver. By minimizing the objective function J, it obtains the optimal control law mapping function Φ, which aims to minimize processing defects. Based on the optimal control law mapping function Φ, the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process. The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output includes laser power P, optical field mode M, double pulse sequence interval Δt, and axial step distance Δz. Based on the evaluated or predicted value of the objective function J, the optimization algorithm iteratively updates the mapping relationship between laser energy input and workpiece material response, and generates the optimal processing parameter set for the (k+1)th sampling control cycle through the optimal control law mapping function Φ. ; ； Where k represents the current k-th sampling control cycle; {P,M,Δt,Δz} k This represents the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance in the k-th sampling control cycle; ΔT k ΔS represents the temperature deviation detected in the k-th sampling control cycle. k The scattered light deviation detected in the k-th sampling control cycle is represented by the optimal control law mapping function Φ, which represents the nonlinear mapping model constructed by the optimization algorithm. Its internal parameters are adjusted in real time according to the gradient descent direction of the objective function J to ensure that the output processing parameters can converge the processing process towards the direction of minimizing defects.

2. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that: The initial laser beam is a picosecond or femtosecond pulsed laser beam with a wavelength of 1020 nm to 1070 nm, a pulse width of 100 fs to 10 ps, ​​a repetition frequency of 100 kHz to 2 MHz, and a power of 0.1 W to 30 W.

3. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that: The dynamic light field modulation module includes a spatial light modulator or a digital micromirror array, and the light field modes include Gaussian mode, vortex mode and flat-top mode. The switching rate of the light field modes is greater than 0 ms and does not exceed 1 ms.

4. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that: The energy density of the preheating pulse is 0.15 J / cm² to 0.35 J / cm², the energy density of the stripping pulse is 0.35 J / cm² to 0.85 J / cm², and the time interval Δt of the dual pulse sequence is 5 μs to 20 μs.

5. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that: The motion module includes a three-axis linkage platform, which is used to carry the workpiece and drive the workpiece to move along the x-axis, y-axis and z-axis of a three-dimensional coordinate system, wherein the z-axis direction is parallel to the axial direction of the microporous structure.

6. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that: The online monitoring module includes an infrared temperature measurement mechanism and a scattered light detection mechanism. The infrared temperature measurement mechanism is used to collect temperature signals generated during the processing, and the scattered light detection mechanism is used to collect scattered light intensity signals generated during the processing.

7. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 6, characterized in that: The infrared temperature measurement mechanism has a temperature measurement band of 3 μm to 5 μm, and the infrared temperature measurement mechanism and the scattered light detection mechanism have a collection frequency of 1 kHz to 5 kHz.

8. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 1, characterized in that, Also includes: A gas-assisted module is provided, which is used to spray protective gas into the processing area of ​​the workpiece. The gas-assisted module is also connected to the controller module.

9. The low-damage CFRP laser drilling device based on dynamic multimode beam control according to claim 8, characterized in that: The spraying distance between the gas-assisted module and the processing area on the workpiece surface is 5 μm to 30 μm, and the spraying angle is 20° to 40°.

10. A low-damage CFRP laser drilling method based on dynamic multimode beam control, characterized in that, include: An initial laser beam is provided by an ultrafast laser source, and the phase or amplitude distribution of the initial laser beam is dynamically modulated by a dynamic optical field control module, so that the optical field mode of the initial laser beam switches between multiple preset modes to form a modulated laser beam. The modulated laser beam is modulated into a dual-pulse sequence with a preset energy difference and a preset time interval using a dual-pulse control module, thereby forming and outputting the controlled laser beam. The dual-pulse sequence includes a preheating pulse and a stripping pulse, wherein the energy density of the preheating pulse is lower than that of the stripping pulse. The control laser beam is focused by the galvanometer scanning module to form a processing laser beam, and the processing laser beam is used to scan and process the workpiece according to a preset scanning trajectory to form a micro-hole structure; The online monitoring module collects the temperature signal and scattered light intensity signal of the workpiece's processing area in real time. The controller module compares the signal collected by the online monitoring module with a preset threshold to obtain the temperature deviation. and scattered light deviation The system employs a preset optimization algorithm as the core solver. By minimizing the objective function J, it obtains the optimal control law mapping function Φ, which aims to minimize processing defects. Based on the optimal control law mapping function Φ, the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process. The objective function of the optimization algorithm is: ； Θ is the width of the heat-affected zone, Θ is the taper of the pore wall, and φ is the thickness of the redeposited layer. α:β:γ is the weighting coefficient ratio, where α:β:γ = 2:2:

1. The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output includes laser power P, optical field mode M, double pulse sequence interval Δt, and axial step distance Δz. Based on the evaluated or predicted value of the objective function J, the optimization algorithm iteratively updates the mapping relationship between laser energy input and workpiece material response, and generates the optimal processing parameter set for the (k+1)th sampling control cycle through the optimal control law mapping function Φ. ; ； Where k represents the current k-th sampling control cycle; {P,M,Δt,Δz} k This represents the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance in the k-th sampling control cycle; ΔT k ΔS represents the temperature deviation detected in the k-th sampling control cycle. k The scattered light deviation detected in the kth sampling control cycle is represented by the optimal control law mapping function Φ, which represents the nonlinear mapping model constructed by the optimization algorithm. Its internal parameters are adjusted in real time according to the gradient descent direction of the objective function J to ensure that the output processing parameters can converge the processing process in the direction of minimizing defects. Furthermore, the processing laser beam is driven by a motion module to generate relative motion with the workpiece along the axial direction of the microporous structure, wherein the workpiece is a carbon fiber reinforced composite material.

11. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The initial laser beam is a picosecond or femtosecond pulsed laser beam with a wavelength of 1020 nm to 1070 nm, a pulse width of 100 fs to 10 ps, ​​a repetition frequency of 100 kHz to 2 MHz, and a power of 0.1 W to 30 W.

12. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The dynamic light field modulation module includes a spatial light modulator or a digital micromirror array, and the light field modes include Gaussian mode, vortex mode and flat-top mode, with the switching rate of the light field modes not exceeding 1 ms.

13. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The energy density of the preheating pulse is 0.15 J / cm² to 0.35 J / cm², the energy density of the stripping pulse is 0.35 J / cm² to 0.85 J / cm², and the time interval Δt of the dual pulse sequence is 5 μs to 20 μs.

14. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The motion module includes a three-axis linkage platform, which is used to carry the workpiece and drive the workpiece to move along the x-axis, y-axis and z-axis of a three-dimensional coordinate system, wherein the z-axis direction is parallel to the axial direction of the microporous structure.

15. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The preset scanning trajectory is a concentric spiral path, with an axial step distance Δz of 5 μm to 30 μm.

16. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The scanning speed of the processing laser beam is 50 mm / s to 500 mm / s.

17. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that: The online monitoring module includes an infrared temperature measurement mechanism and a scattered light detection mechanism. The infrared temperature measurement mechanism is used to collect temperature signals generated during the processing, and the scattered light detection mechanism is used to collect scattered light intensity signals generated during the processing.

18. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 17, characterized in that: The infrared temperature measurement mechanism has a temperature measurement band of 3 μm to 5 μm, and the infrared temperature measurement mechanism and the scattered light detection mechanism have a collection frequency of 1 kHz to 5 kHz.

19. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 10, characterized in that, Also includes: During the scanning and processing of the workpiece using a processing laser beam, a gas-assisted module sprays protective gas onto the processing area on the workpiece surface.

20. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 19, characterized in that: The spraying distance between the gas-assisted module and the processing area on the workpiece surface is 5 μm to 30 μm, the spraying angle is 20° to 40°, and the spraying flow rate is 30 L / min to 80 L / min.

21. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to claim 19, characterized in that: The protective gas is an inert gas.

22. The low-damage CFRP laser drilling method based on dynamic multimode beam control according to any one of claims 10-21, characterized in that, The low-damage CFRP laser drilling method based on dynamic multimode beam control is implemented based on the low-damage CFRP laser drilling device based on dynamic multimode beam control as described in any one of claims 1-9.

23. A laser processing control method, used in the low-damage CFRP laser drilling device based on dynamic multimode beam control as described in any one of claims 1-9 or the low-damage CFRP laser drilling method based on dynamic multimode beam control as described in any one of claims 10-22; Its features are, include: Temperature and scattered light intensity signals are collected during laser processing. The collected temperature and scattered light intensity signals are compared with preset thresholds to obtain the temperature deviation. and scattered light deviation The system employs a preset optimization algorithm as the core solver. By minimizing the objective function J, it obtains the optimal control law mapping function Φ, which aims to minimize processing defects. Based on the optimal control law mapping function Φ, the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance of the laser processing are adjusted in real time to achieve adaptive control of the processing process. The objective function of the optimization algorithm is: ； Θ is the width of the heat-affected zone, Θ is the taper of the pore wall, and φ is the thickness of the redeposited layer. α:β:γ is the weighting coefficient ratio, where α:β:γ = 2:2:

1. The controller module employs either Extreme Learning Machine (ELM) or Bayesian optimization algorithms, with temperature deviation as the input. and scattered light deviation The output includes laser power P, optical field mode M, double pulse sequence interval Δt, and axial step distance Δz. Based on the evaluated or predicted value of the objective function J, the optimization algorithm iteratively updates the mapping relationship between laser energy input and workpiece material response, and generates the optimal processing parameter set for the (k+1)th sampling control cycle through the optimal control law mapping function Φ. ; ； Where k represents the current k-th sampling control cycle; {P,M,Δt,Δz} k This represents the laser power, optical field mode, time interval of the double pulse sequence, and axial step distance in the k-th sampling control cycle; ΔT k ΔS represents the temperature deviation detected in the k-th sampling control cycle. k The scattered light deviation detected in the k-th sampling control cycle is represented by the optimal control law mapping function Φ, which represents the nonlinear mapping model constructed by the optimization algorithm. Its internal parameters are adjusted in real time according to the gradient descent direction of the objective function J to ensure that the output processing parameters can converge the processing process towards the direction of minimizing defects.

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