Intelligent laser cutting device and method for hair dryer metal mesh cover

Abstract

The application is suitable for the field of laser processing technology, and provides an intelligent laser cutting device and method for a hair dryer metal mesh cover, wherein the intelligent laser cutting method for the hair dryer metal mesh cover comprises the following steps: extracting three-dimensional model data of the hair dryer metal mesh cover, cutting head initial processing track, laser basic emission power and beam waist radius of the laser beam; performing normalization processing on a cutting head main shaft direction vector and a local surface normal vector at a current interpolation point, constructing a beam energy coupling distortion model based on a space dynamic tilt angle, and outputting effective laser power density at the current interpolation point. Through the construction of the beam energy coupling distortion model based on the space dynamic tilt angle, the normalization processing is performed on the cutting head main shaft direction vector and the surface normal vector, the effective laser power density dynamically changing with the incident angle is accurately calculated, and the energy coupling distortion problem in the free surface laser cutting is effectively solved.

Description

Technical Field

[0001] This invention belongs to the field of laser processing technology, and in particular relates to an intelligent laser cutting method for a metal mesh cover of a hair dryer. Background Technology

[0002] As a key aesthetic and protective component of household appliances, the metal mesh cover of a hair dryer is typically formed by stamping thin-walled stainless steel or galvanized steel sheets. With consumers' increasing demands for product appearance quality and ventilation performance, the precision of the micro-hole arrangement, the surface quality of the hole walls, and the overall surface contour have become core indicators for measuring product quality. Laser cutting technology is gradually being introduced into the micro-hole processing of metal mesh covers to replace traditional mechanical stamping processes.

[0003] However, in practical laser cutting applications, existing technologies face multiple systemic defects.

[0004] First, the freeform surface characteristics of the metal mesh cover result in a dynamically changing tilt angle between the cutting head's main axis and the local normal vector of the mesh cover surface. As the tilt angle increases, the projected area of ​​the laser spot on the curved surface significantly expands, leading to a sharp decrease in effective laser power density. Current process planning is generally based on the simplified assumption of perpendicular laser incidence, failing to establish a precise mathematical model of the coupling between the spatial dynamic tilt angle and beam energy. This results in significant differences in heat input to the micro-holes in different regions, causing uneven cutting quality, manifested as localized aperture deviations, excessive melting of the hole walls, or incomplete cutting.

[0005] Secondly, during the fabrication of dense micro-hole arrays, the thermal effects of the previously processed holes have not completely dissipated before subsequent holes are cut. The cumulative thermal effect causes the transient temperature rise in local areas to far exceed the level of single-hole processing. This cumulative temperature rise induces non-uniform thermo-elastic-plastic deformation of the mesh surface along the normal direction of the curved surface through the material's thermal expansion and thermal buckling mechanisms. Existing technologies lack the ability to trace the spatiotemporal effects of historical thermal action and cannot accurately quantify the transient cumulative temperature rise and its resulting deformation at each interpolation point. This leads to a shift in the positioning reference of subsequent holes, affecting the overall geometric accuracy of the micro-hole array.

[0006] To address the aforementioned issues, existing technologies urgently need improvement. Summary of the Invention

[0007] The purpose of this invention is to provide an intelligent laser cutting method for the metal mesh cover of a hair dryer, aiming to solve the above-mentioned problems.

[0008] This invention is implemented as follows: a smart laser cutting method for a hair dryer metal mesh cover, comprising the following steps:

[0009] Step S1: Extract the 3D model data of the metal mesh cover of the hair dryer, the initial processing trajectory of the cutting head, the basic emission power of the laser, and the beam waist radius of the laser beam; normalize the main axis direction vector of the cutting head and the local surface normal vector at the current interpolation point, construct a beam energy coupling distortion model based on the spatial dynamic tilt angle, and output the effective laser power density at the current interpolation point.

[0010] Step S2: Extract the material physical property parameters of the metal mesh cover, the set of spatial coordinates of the historically cut micro-hole array, and the laser dwell time of a single hole; use the effective laser power density as the heat source parameter to construct a discrete-time thermal integral model of the moving body based on the Green's function, and calculate the transient cumulative temperature rise at the current interpolation point; substitute the transient cumulative temperature rise into the thermal buckling mapping model to output the thermo-elastic-plastic deformation of the thin-walled mesh cover surface along the normal of the curved surface;

[0011] Step S3: Extract the auxiliary gas nozzle outlet diameter, ideal nozzle overhang height, free diffusion half angle of the gas jet, local porosity in the neighborhood of the current cutting point, and target air pressure at the cutting front; introduce the thermo-elastic-plastic deformation into the jet dispersion evolution equation, construct an aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect, and output a servo air pressure compensation command to offset the air pressure leakage and the actual nozzle height fluctuation;

[0012] Step S4: Extract the Rayleigh length of the laser beam and the original theoretical three-dimensional coordinate vector of the current interpolation point; vector superposition the spatial focus offset based on geometric optics theory with the thermo-elastic-plastic deformation to construct a strong coupling inverse compensation interpolation model of optomechanical-flow multiphysics field, output the final three-dimensional execution coordinates after offset compensation along the local normalized normal vector direction of the surface, and send them to the CNC laser processing servo system for cutting.

[0013] In a further technical solution, the specific method for normalizing the cutting head spindle direction vector and the local surface normal vector at the current interpolation point in step S1 is as follows: calculate the magnitude of the original normal vector and the magnitude of the original direction vector at the current interpolation point respectively; divide the original normal vector by the magnitude to obtain the normalized unit normal vector; divide the original direction vector by the magnitude of the original direction vector to obtain the normalized unit direction vector.

[0014] In a further technical solution, the specific method for constructing the beam energy coupling distortion model based on the spatial dynamic tilt angle and outputting the effective laser power density at the current interpolation point in step S1 is as follows:

[0015] First, calculate the power density baseline by dividing the base emission power of the laser by the product of pi and the square of the laser beam waist radius. Then, calculate the dot product of the normalized unit normal vector and the normalized unit direction vector to obtain the tilt angle coupling factor. Multiply the power density baseline by the tilt angle coupling factor to obtain the effective laser power density. This calculation is only valid if the dot product value is greater than zero. If the dot product value is less than or equal to zero, the interpolation point is determined to be unreachable, and the processing of that point is skipped.

[0016] In a further technical solution, in step S2, the specific method for constructing the discrete-time thermal integral model of the moving body based on the Green's function and calculating the transient cumulative temperature rise at the current interpolation point is as follows: All previously cut holes are summed, and the following calculations are performed for each historical hole:

[0017] The first step is to multiply the effective laser power density at the historical aperture by the product of pi and the square of the laser beam waist radius, and then multiply by the laser dwell time of a single aperture to obtain the total energy of the pulse heat source of a single aperture. Then multiply by the absorptivity constant of the mesh material to the laser to obtain the effective heat source energy actually absorbed by the material.

[0018] The second step is to first calculate the density of the mesh material and multiply it by the specific heat capacity of the mesh material to obtain the volumetric heat capacity. Then, calculate the product of four times pi, the thermal diffusivity of the mesh material, and the time interval between the historical hole and the current hole. Then, take the cube of 2 of the product and finally multiply the cube of 2 result by the volumetric heat capacity to obtain the heat capacity-diffusion coupling denominator.

[0019] The third step is to calculate the square of the spatial Euclidean distance between the historical hole center and the current hole center, divide it by the product of four times the thermal diffusivity and the time interval, take the negative value of the quotient, and calculate the exponential function value with the natural constant e as the base to obtain the spatial thermal diffusivity attenuation factor.

[0020] The fourth step is to divide the effective heat source energy mentioned in the first step by the denominator term of the heat capacity-diffusion coupling mentioned in the second step, and then multiply it by the spatial heat diffusion attenuation factor mentioned in the third step to obtain the temperature rise contribution value of the historical hole to the current hole.

[0021] The transient cumulative temperature rise at the current interpolation point is obtained by summing the temperature rise contributions of all historical holes.

[0022] A further technical solution, in step S2, is as follows: Substituting the transient cumulative temperature rise into the thermal buckling mapping model and outputting the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal direction of the curved surface is done as follows: First, calculate the ratio obtained by dividing the transient cumulative temperature rise by the melting point temperature of the mesh material; take the hyperbolic tangent function value of this ratio to obtain the thermal buckling modulation factor; then calculate the unsupported local span of the mesh in the current region multiplied by the linear thermal expansion coefficient and then multiplied by the transient cumulative temperature rise to obtain the basic thermal expansion; multiply the basic thermal expansion by the thermal buckling modulation factor to obtain the thermo-elastic-plastic deformation along the normal direction of the curved surface.

[0023] In a further technical solution, the specific method for constructing the aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect and outputting the air pressure compensation command in step S3 is as follows:

[0024] The first step is to calculate the dot product of the normalized unit normal vector and the unit vector in the nozzle axis direction to obtain the direction projection factor. Then, multiply the direction projection factor by the thermo-elastic-plastic deformation along the surface normal to obtain the actual deformation along the nozzle axis direction.

[0025] The second step is to first calculate the difference between the nozzle overhang height under ideal conditions and the actual deformation along the nozzle axis, then multiply it by the tangent of twice the free diffusion half angle of the gas jet to obtain the diffusion radius increment, and then add the diffusion radius increment to the nozzle outlet diameter to obtain the effective diameter of the jet after diffusion.

[0026] The third step is to divide the effective diameter by the nozzle outlet diameter, and then square the ratio to obtain the jet compression ratio correction term.

[0027] The fourth step is to subtract the local porosity from the difference, and then take the negative cube of the difference to obtain the leakage correction factor.

[0028] The fifth step is to multiply the effective air pressure at the target cutting front by the jet compression ratio correction term and then by the leakage correction factor to obtain the servo air pressure compensation command value at the current interpolation point.

[0029] In a further technical solution, the specific method for constructing the optomechanical-flow multiphysics field strongly coupled inverse compensation interpolation model and outputting the final three-dimensional execution coordinates in step S4 is as follows:

[0030] First, calculate the dot product of the normalized unit normal vector and the normalized unit direction vector to obtain the tilt angle projection factor. Then, multiply the tilt angle projection factor by the Rayleigh length of the laser beam to obtain the optical focus offset component along the surface normal. Add the thermo-elastic-plastic deformation along the surface normal to the optical focus offset component to obtain the total compensation offset along the normal. Then, multiply the total compensation offset by the normalized unit normal vector to obtain the three-dimensional compensation offset vector. Finally, add the three-dimensional compensation offset vector to the original theoretical three-dimensional coordinate vector of the current interpolation point to obtain the final three-dimensional execution coordinate vector after multiphysics compensation.

[0031] A smart laser cutting device for a hair dryer metal mesh cover, applied to the above-mentioned method, includes:

[0032] The data acquisition module is used to acquire 3D model data, initial processing trajectory, laser power, and beam waist radius;

[0033] The power density calculation module is used to normalize the cutting head's main axis direction vector and the surface normal vector, construct a beam energy coupling distortion model, and output the effective laser power density.

[0034] The thermal deformation calculation module is used to calculate the transient cumulative temperature rise based on the Green's function thermal integral model and substitute it into the thermal buckling mapping model to output the thermoelastic-plastic deformation.

[0035] The air pressure compensation module is used to introduce the deformation and local porosity, construct a dynamic pressure leakage compensation model, and output servo air pressure compensation commands.

[0036] The coordinate compensation module is used to superimpose the focus offset with the deformation vector, output the compensated three-dimensional execution coordinates, and send them to the CNC servo system.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] This invention constructs a beam energy coupling distortion model based on the spatial dynamic tilt angle, normalizes the cutting head principal axis direction vector and the surface normal vector, and accurately calculates the effective laser power density that dynamically changes with the incident angle. This effectively solves the energy coupling distortion problem caused by the change of tilt angle in free-form surface laser cutting, and significantly improves the uniformity of heat input to micro-holes in different regions and the consistency of cutting quality.

[0039] This invention constructs a discrete-time thermal integral model of a moving body based on Green's function, which spatiotemporally superimposes the thermal contributions of historically cut microholes, accurately quantifies the transient cumulative temperature rise at the current interpolation point, and combines it with a thermal buckling mapping model to output the thermo-elastic-plastic deformation along the surface normal. This enables accurate prediction and quantification of the thermal accumulation effect and the resulting positioning reference offset in the processing of dense microholes, effectively improving the overall geometric accuracy of the microhole array.

[0040] This invention introduces thermoelastic-plastic deformation into the jet dispersion evolution equation and couples it with local porosity to construct an aerodynamic dynamic pressure leakage compensation model. It dynamically outputs servo air pressure compensation commands, which can offset the nozzle height fluctuation caused by workpiece deformation and the air pressure leakage caused by the hollow structure in real time, ensuring that the cutting front edge always maintains the target air pressure, effectively guaranteeing the slag removal effect and the stability of the cutting process.

[0041] This invention constructs a strong coupling inverse compensation interpolation model of optomechanical-fluidic multiphysics fields, and vectorically superimposes the optical focus offset and thermo-elastic-plastic deformation to output the final three-dimensional execution coordinates after offset compensation along the normal of the curved surface. This achieves coordinated real-time compensation of optical, thermodynamic and fluid dynamic multiphysics field effects, and simultaneously corrects the focus deviation and theoretical position deviation, which greatly improves the processing accuracy and product yield of laser cutting of complex curved thin-walled mesh covers. Attached Figure Description

[0042] Figure 1 A schematic diagram illustrating the steps of an intelligent laser cutting method for a hair dryer's metal mesh cover;

[0043] Figure 2 Here is the logic block diagram for the power density calculation module;

[0044] Figure 3 Here is the logic block diagram for the thermal deformation calculation module;

[0045] Figure 4 Here is the logic block diagram of the air pressure compensation module;

[0046] Figure 5 This is the logic block diagram of the coordinate compensation module. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0049] like Figures 1-5 As shown, an intelligent laser cutting method for a hair dryer metal mesh cover provided in one embodiment of the present invention includes the following steps:

[0050] In step S1, the first step is to acquire the 3D model data of the blower's metal mesh cover, the initial machining trajectory of the cutting head, the basic emission power of the laser, and the beam waist radius of the laser beam. This data can be obtained in various ways. For example, the 3D model data can be directly exported from design software, the initial machining trajectory can be generated by the operator through teach programming, and the basic emission power of the laser and the beam waist radius can be manually input according to the specifications of the laser equipment or read from the equipment controller. Subsequently, the cutting head's main axis direction vector and the local surface normal vector at the current interpolation point are normalized.

[0051] Based on this, a beam energy coupling distortion model based on the spatial dynamic tilt angle is constructed, and the effective laser power density at the current interpolation point is output. In some simplified applications, the influence of the dynamic tilt angle can be ignored, and the effective laser power density can be estimated by directly dividing the laser's base emission power by a fixed spot area, without considering the change in energy coupling efficiency caused by the actual incident angle.

[0052] In step S2, it is necessary to extract the material physical property parameters of the metal mesh cover, the set of spatial coordinates of the historically cut micro-hole array, and the laser dwell time of a single hole. The material physical property parameters can be obtained from the technical specifications provided by the material supplier. The set of spatial coordinates of the historically cut micro-hole array can be stored using a simple position recording system, for example, recording the center coordinates after each hole is cut. The laser dwell time of a single hole can be set based on empirical values ​​or preset process parameters. Next, using the effective laser power density as a heat source parameter, a discrete-time thermal integral model of the moving body based on the Green's function is constructed to calculate the transient cumulative temperature rise at the current interpolation point.

[0053] Subsequently, the transient cumulative temperature rise is substituted into the thermal buckling mapping model to output the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal direction of the curved surface. In some cases, the thermal buckling effect can be ignored, and a simple axial expansion can be estimated solely through the linear thermal expansion coefficient of the material and the temperature rise, without considering the complex deformation of the thin-walled structure under thermal stress.

[0054] In step S3, it is necessary to extract the auxiliary gas nozzle outlet diameter, ideal nozzle overhang height, gas jet free diffusion half-angle, local porosity in the neighborhood of the current cutting point, and target gas pressure at the cutting front. These parameters can be obtained from the nozzle manufacturer's specifications or through experimental measurement. Local porosity can be ignored in simplified processing or an average value can be set manually based on experience. The target gas pressure at the cutting front can be preset to a fixed value based on the material type and thickness.

[0055] Subsequently, the thermoelastic-plastic deformation was introduced into the jet dispersion evolution equation to construct an aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect, and output a servo pressure compensation command to offset the pressure leakage and the actual nozzle height fluctuation.

[0056] In step S4, it is necessary to extract the Rayleigh length of the laser beam and the original theoretical 3D coordinate vector of the current interpolation point. The Rayleigh length of the laser beam is an inherent parameter of the laser and can be found in the equipment manual. The original theoretical 3D coordinate vector of the current interpolation point can be directly obtained from the G-code generated by the CNC programming software.

[0057] Finally, the spatial focal offset based on geometric optics theory is vector-superimposed with the thermo-elastic-plastic deformation to construct a strongly coupled optomechanical-flow multiphysics inverse compensation interpolation model. This model outputs the final three-dimensional execution coordinates after offset compensation along the locally normalized normal vector direction of the surface, and sends them to the CNC machine tool servo system for cutting. Without considering focal offset and thermo-elastic-plastic deformation, the CNC machine tool can directly cut according to the original theoretical three-dimensional coordinate vector without any form of trajectory compensation.

[0058] In this embodiment, addressing the issue that existing CNC interpolation methods fail to coordinate compensation for focal offset and surface deformation, a strongly coupled optomechanical-flow multiphysics inverse compensation interpolation model is constructed in step S4. This model vector-superimposes the spatial focal offset based on geometric optics theory with the thermo-elastic-plastic deformation, outputting the final three-dimensional execution coordinates after offset compensation. This comprehensive compensation strategy ensures that the laser focal point always accurately acts on the material surface, and the cutting trajectory accurately adapts to the dynamic deformation of the material, thereby fundamentally guaranteeing the accuracy and stability of complex curved surface micro-hole machining.

[0059] In a preferred embodiment of the present invention, the mathematical formula for normalizing the cutting head spindle direction vector and the local surface normal vector at the current interpolation point in step S10 is as follows:

[0060] ;

[0061] in This represents the unit normal vector of the metal mesh surface at the k-th interpolation point after normalization. This represents the original normal vector of the metal mesh surface at the kth interpolation point; Represents the original normal vector The modulus length; This represents the unit direction vector of the cutting head spindle after normalization at the kth interpolation point; This represents the original direction vector of the cutting head's main axis at the kth interpolation point; Represents the original direction vector The length of the module.

[0062] In this embodiment, the explicit definition of these symbols ensures the clarity and operability of the formulas, laying the foundation for subsequent accurate calculations. In practical implementation, these raw vector data can be directly extracted from the 3D CAD model, for example, by performing geometric analysis on the mesh surface to obtain the local surface normal vector, and by obtaining the direction vector of the cutting head spindle through the kinematic model of the CNC machine tool. Normalization calculations can be implemented using vector processing functions or mathematical libraries in programming languages, for example, by executing them within the calculation module of the CNC system.

[0063] This application's solution normalizes the cutting head's main axis direction vector and the local surface normal vector at the current interpolation point. This ensures that when constructing a beam energy coupling distortion model based on the spatial dynamic tilt angle, the vectors used only reflect their directional characteristics, excluding interference from their modulus. In the above method, step S1 requires calculating the relative tilt angle between the laser beam and the workpiece surface, which is typically achieved through the dot product of two direction vectors. If the modulus of the original vectors is inconsistent or not unit length, the dot product result will not only contain angle information but will also be affected by the modulus size, leading to inaccurate calculations of the spatial dynamic tilt angle. By normalizing these two vectors to unit vectors, i.e. and With a modulus of 1, their dot product directly and accurately reflects the cosine of the angle between them, thus precisely characterizing the relative tilt of the laser beam and the workpiece surface. This precise directional information is a key input for constructing an accurate beam energy coupling distortion model, enabling the subsequently calculated effective laser power density to truly reflect the actual situation of laser energy projected onto the mesh surface at different tilt angles, providing a foundation for achieving high-precision laser cutting.

[0064] In a preferred embodiment of the present invention, in step S10, a beam energy coupling distortion model based on the spatial dynamic tilt angle is constructed, and the mathematical formula for calculating the effective laser power density at the current interpolation point is output as follows:

[0065]

[0066] in, This represents the effective laser power density projected onto the surface of the mesh at the k-th interpolation point, with dimensions in W / m². 2 ; This represents the fundamental emission power of the laser, with dimensions in W; This represents the beam waist radius of the laser beam, with dimensions in meters; and further specifies that it only applies when... Valid for a period of time, if If the interpolation point is unreachable, then the processing at that point should be skipped.

[0067] In this embodiment, a beam energy coupling distortion model based on the spatial dynamic tilt angle is constructed. Its purpose is to accurately simulate and compensate for the changes in the projection and absorption efficiency of the laser beam's energy onto the curved surface under different incident angles. This model predicts the actual energy density acting on the material by considering the relative attitude between the laser beam and the surface normal. This can be achieved through geometric projection relationships, such as using the vector dot product to obtain the angle cosine value, thereby correcting the theoretical power density. Another implementation method is to directly obtain the corresponding energy coupling coefficient based on the angle between the laser beam and the surface normal using a pre-established lookup table or empirical formula. The output effective laser power density at the current interpolation point refers to the laser energy density that actually acts on the metal mesh surface and can be effectively absorbed by the material after the above model correction. This parameter is a key input for subsequent thermal effect analysis and cutting path planning; its accuracy directly affects cutting quality and thermal deformation control. Its output value is calculated based on the original parameters of the laser and the relative geometric relationship between the laser beam and the curved surface, representing the actual intensity of the laser's action at a specific processing point. Mathematical calculation formula. The effective laser power density is specifically defined. The calculation method.

[0068] in, This represents the maximum power density of a laser beam under ideal perpendicular incidence, typically corresponding to the peak power density of a Gaussian beam. It is the normalized unit normal vector of the metal mesh surface. Unit direction vector of the cutting head spindle The dot product is the physical representation of the angle between the laser beam and the surface normal, quantifying the degree of inclination of the laser beam relative to the surface. When the laser beam is perpendicular to the surface, the dot product is 1, resulting in the maximum effective power density; when the laser beam is tilted, the dot product is less than 1, and the effective power density decreases accordingly, thus accurately reflecting the distortion of energy coupling.

[0069] Only when Valid for a period of time, if If the dot product of the normalized normal vector and the normalized direction vector is greater than 0, it indicates that the laser beam is roughly pointing inside the curved surface, i.e., the incident angle is less than 90 degrees. In this case, the laser energy can be effectively coupled into the material for cutting. If the dot product is less than or equal to 0, it means that the laser beam is tangential to or away from the curved surface. In this case, the laser energy cannot be effectively applied to the cutting point, or it may cause problems such as light path obstruction or reflection. In this situation, the system will intelligently determine that the interpolation point is unreachable and skip the processing of that point, thereby avoiding invalid cutting, energy waste, and potential damage to the equipment or workpiece.

[0070] In a preferred embodiment of the present invention, in step S20, a discrete-time thermal integral model of the moving body based on the Green's function is constructed, and the mathematical formula for calculating the transient cumulative temperature rise at the current interpolation point is as follows:

[0071]

[0072] in, The value represents the transient cumulative temperature rise at the k-th interpolation point due to historical cutting, with the dimension K; i represents the index number of the historically cut hole; k represents the index number of the current interpolation point. This represents the absorptivity constant of the mesh material to laser light, and is dimensionless. The effective laser power density at the i-th aperture is represented by the input coupled in step S10, and its dimension is W / m. 2 ; The laser dwell time during single mesh cutting is expressed in seconds. This indicates the density of the mesh material, with dimensions in kg / m³. 3 ; This indicates the specific heat capacity of the mesh material, with dimensions of . ; The thermal diffusivity of the mesh material is expressed in units of m. 2 / s; This represents the time interval from the completion of cutting the i-th hole to the start of cutting the k-th hole, with the dimension s; Let represent the spatial Euclidean distance between the center of the i-th hole and the center of the k-th hole, with dimensions m.

[0073] In this embodiment, the Green's function-based discrete-time thermal integral model of the moving body aims to quantify the cumulative thermal effect of historical cutting points on the current cutting point during laser cutting. The Green's function is a mathematical tool used to solve partial differential equations; here, it describes the transient temperature field as a point heat source propagates and decays within the material.

[0074] The discrete-time thermal integral model for moving bodies discretizes the continuous laser cutting process into a series of moving point heat sources. By integrating and superimposing the thermal contributions of these heat sources at different times and spatial locations, the cumulative temperature rise at any point at any time can be calculated. Implementation methods can include: discretizing the cutting trajectory into a series of small time steps and spatial points; treating the laser action as an instantaneous point heat source within each time step; calculating its temperature distribution in the material using the Green's function; and then superimposing the contributions of all historical point heat sources; or, establishing a mesh within the material domain, solving the transient heat conduction equation using the finite element or finite difference methods, and introducing the Green's function as a boundary condition or source term to more accurately simulate the thermal diffusion process under complex geometries and boundary conditions.

[0075] Transient cumulative temperature rise refers to the temperature increase at the current cutting point before laser irradiation due to heat accumulation from previously cut holes during laser cutting. Accurately calculating this temperature rise is crucial for predicting material thermal deformation. This calculation is achieved using the aforementioned Green's function model, taking into account the effective laser power density at historical cutting points, laser dwell time, the material's thermophysical properties, and the time and spatial distance between historical and current points.

[0076] in, This is the direct output of the model calculation, reflecting the degree of thermal impact on the current point before cutting; i is used to traverse all previously cut holes that have a thermal impact on the current point; k refers to the point to be cut that is currently being calculated. This reflects the efficiency of the material in absorbing laser energy, and the absorption constant of the metal mesh material to laser can be obtained directly from the technical specifications provided by the material supplier. The accuracy of the heat source intensity is ensured by the calculation based on the beam energy coupling distortion model in step S1. Affects the amount of heat input; and The magnitude of the temperature rise of the material is affected; This determines the speed at which heat travels through the material; and These reflect the temporal and spatial factors of heat diffusion and loss, respectively.

[0077] In the intelligent laser cutting method for the metal mesh cover of a hair dryer, the relevant parameters of the laser and the cutting head are first acquired and processed in step S1, and the effective laser power density at the current interpolation point is calculated by combining the curved surface characteristics of the mesh cover. Building upon this, to accurately assess the thermal effects on the material during laser cutting, this application further constructs a discrete-time thermal integral model of the moving body based on a Green's function in step S2, utilizing the material physical property parameters of the metal mesh cover, the spatial coordinate set of historically cut micro-hole arrays, and the laser dwell time of a single hole. This model incorporates the previously calculated effective laser power density. As a heat source parameter, the transient cumulative temperature rise at the current cutting point is calculated by precisely integrating the thermal contributions of all historically cut holes in time and space. .

[0078] Specifically, the model treats each historical cut hole as an instantaneous point heat source, the intensity of which is determined by the effective laser power density at that hole. and laser dwell time The Green's function describes how these point heat sources change over time in materials with specific thermophysical properties. and spatial distance Propagation and attenuation. By superimposing the thermal effects of all historical cutting holes, the accumulated temperature rise at the current interpolation point before cutting can be obtained. This method can precisely capture the dynamic accumulation and diffusion process of heat in the thin-walled mesh during laser cutting, providing an accurate temperature field input for subsequent thermo-elastic-plastic deformation prediction, thus overcoming the thermal deformation problem caused by insufficient consideration of thermal effects in traditional cutting methods.

[0079] In a preferred embodiment of the present invention, in step S20, the transient cumulative temperature rise is substituted into the thermal buckling mapping model, and the mathematical formula for calculating the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal direction of the curved surface is output as follows:

[0080]

[0081] in, The thermoelastic-plastic deformation of the mesh surface along the normal direction at the k-th interpolation point is represented by the dimension m; This represents the unsupported local span of the netting in the current area, with the dimension in meters; This represents the linear thermal expansion coefficient of the mesh material, with dimensions 1 / K. This indicates the melting point temperature of the mesh material, with dimensions in K.

[0082] In this embodiment, the thermal buckling mapping model is a mathematical or physical model used to describe the deformation of materials under thermal load. Its function is to convert the transient cumulative temperature rise caused by laser cutting into quantifiable physical deformation, thereby providing accurate input for subsequent compensation mechanisms. This model can be implemented based on empirical formulas, simplified mechanical analysis, or lookup tables or approximate functions pre-established through finite element analysis.

[0083] Thermo-elastic-plastic deformation of thin-walled mesh surface along the normal direction of the curved surface , representing the displacement perpendicular to the local curvature of the mesh surface at the k-th interpolation point due to thermal effects. This deformation is the result of the combined effects of thermal expansion and thermal buckling, and is particularly significant for thin-walled structures. Accurately obtaining this deformation is crucial for achieving high-precision laser cutting, as it directly affects the relative distance between the cutting head and the workpiece, as well as the position of the laser focal point. This deformation can be measured in real time using sensors or predicted by establishing a physical model.

[0084] The unsupported local span of the netting in the current area This refers to the size of the area in a mesh structure that has no direct support near the current cut point. This parameter is an important geometric factor affecting the degree of thermal buckling deformation of thin-walled structures, and can usually be extracted from the three-dimensional model data of the mesh or dynamically calculated based on the cutting path and the cut area.

[0085] The linear thermal expansion coefficient of the mesh material Dimensionality is an inherent property of a material's dimensional change when temperature changes, and can be obtained by consulting material handbooks or conducting experimental measurements. The melting point temperature of the mesh material. The temperature at which a material changes from a solid to a liquid state is an inherent property of the material and has a significant impact on the nonlinear behavior of thermoelastic-plastic deformation. It is usually obtained by consulting a material handbook.

[0086] The solution in this application is to calculate the transient cumulative temperature rise in the aforementioned steps. Combined with the linear thermal expansion coefficient of the mesh material Melting point temperature And the unsupported local span of the netting in the current area Substituting the values ​​into the thermal buckling mapping model, the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal direction of the curved surface is calculated. This model utilizes the hyperbolic tangent function. This describes the nonlinear characteristics of deformation as a function of temperature, especially as the temperature approaches the material's melting point, where the deformation behavior changes significantly.

[0087] In this way, this application can accurately quantify the physical deformation of the mesh surface caused by laser thermal input, providing precise geometric input for subsequent pressure compensation and coordinate compensation, thereby ensuring the stability and accuracy of the laser cutting process. This accurate prediction of thermally induced deformation allows the system to move beyond simple thermal effect analysis to the level of physical geometric deformation, laying the foundation for achieving true intelligent compensation.

[0088] In a preferred embodiment of the present invention, the mathematical calculation formula for constructing the aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect and outputting the air pressure compensation command in step S30 is as follows: ;

[0089] in , Let be the unit vector along the nozzle axis; if the nozzle axis is parallel to the Z-axis of the laser processing technology, then... ; This represents the servo air pressure compensation command value sent to the proportional valve at the k-th interpolation point, with the dimension of Pa; This represents the effective gas pressure at the target cutting front required to ensure successful slag removal, expressed in Pa. This indicates the outlet diameter of the cutting head nozzle, with the dimension in meters (m). This represents the nozzle overhang height under ideal conditions, with the dimension in meters (m). This represents the free diffusion half-angle of the auxiliary gas jet after it leaves the nozzle. It can be obtained by consulting the nozzle manufacturer's specifications or by conducting an auxiliary gas jet diffusion experiment. It is dimensionless. This represents the local porosity within the orthographic projection area of ​​the nozzle surrounding the current k-th interpolation point. It can be obtained by setting an average value manually or by calculating in real time based on the proportion of the area of ​​the cut micro-holes within the orthographic projection area of ​​the nozzle surrounding the current interpolation point. It is dimensionless.

[0090] In this embodiment, introducing the thermo-elastic-plastic deformation into the jet divergence evolution equation refers to incorporating the local deformation of the workpiece surface caused by thermal effects. The deformation is incorporated into the calculation of auxiliary gas jet diffusion and pressure distribution. This allows the airflow model to more accurately simulate the influence of workpiece surface deformation on the airflow path and effective nozzle height under actual cutting conditions. Specifically, the deformation can be directly substituted into the geometric or hydrodynamic model describing jet diffusion as a correction term for the distance between the nozzle and the workpiece; alternatively, computational fluid dynamics simulation software can be used to simulate the gas flow field by using the deformed workpiece geometry as a boundary condition, thereby indirectly realizing the influence of deformation on jet evolution.

[0091] An aerodynamic pressure leakage compensation model coupled with the perforation leakage effect is constructed to quantify the auxiliary gas pressure loss caused by workpiece surface deformation and cut holes (perforations), and to calculate the additional pressure value required for compensation. This model combines the influence of thermal deformation on nozzle height with the influence of local porosity on gas leakage, forming a comprehensive compensation mechanism. The model can be based on fluid dynamics principles, establishing a set of mathematical equations describing gas jet diffusion, impact, and leakage through holes, and then corrected with empirical coefficients; alternatively, it can utilize machine learning algorithms, training the model with a large amount of experimental data (including pressure measurements under different deformations, porosities, and nozzle heights) to predict the required compensation pressure under specific conditions.

[0092] The servo air pressure compensation command, used to offset air pressure leakage and fluctuations in actual nozzle height, refers to the result calculated based on the compensation model, used to adjust the pressure output of the auxiliary gas supply system in real time. Its purpose is to ensure that, during the cutting process, regardless of workpiece deformation or porosity changes, the effective air pressure at the cutting edge remains at the target value, thereby guaranteeing cutting quality. This compensation command value can be directly sent to the proportional valve controller in the CNC system, which adjusts the flow and pressure of the auxiliary gas in real time; alternatively, it can be implemented through a closed-loop control system, where a pressure sensor is installed at the cutting edge to feed back the real-time pressure to the controller. The controller then iteratively adjusts based on the compensation model and the feedback value until the target air pressure is reached.

[0093] The solution of this application is to calculate the thermoelastic-plastic deformation in the above steps. This is incorporated into the aerodynamic dynamic pressure leakage compensation model, and combined with the local porosity in the neighborhood of the current cutting point. It can accurately predict the actual effective pressure of the assist gas at the cutting front. Specifically, the axial component of the thermo-elastic-plastic deformation. This directly modifies the effective distance between the nozzle and the workpiece, thus affecting the diffusion characteristics and dynamic pressure distribution of the gas jet. Simultaneously, local porosity quantifies the extent of auxiliary gas leakage through the cut holes. By coupling these two key factors into a unified mathematical model, the system can calculate the gas pressure required to maintain the target cutting front under the current workpiece conditions. Required precise servo air pressure compensation commands The instruction was then sent to the auxiliary gas supply system to adjust the gas pressure in real time, thereby effectively offsetting the nozzle height fluctuations caused by workpiece deformation and the gas pressure leakage caused by the hollowing effect, ensuring that the auxiliary gas pressure is always at the optimal level during the cutting process.

[0094] In a preferred embodiment of the present invention, the mathematical formula for constructing the optomechanical flow multiphysics field strong coupling inverse compensation interpolation model and outputting the final three-dimensional execution coordinates in step S40 is as follows:

[0095]

[0096] in This represents the final three-dimensional execution coordinate vector of the kth interpolation point after multiphysics compensation, with the dimension m; Let represent the original theoretical three-dimensional coordinate vector of the k-th interpolation point, with dimensions m; The Rayleigh length of a laser beam is expressed in meters (m). It is the effective projection component of the Rayleigh length along the surface normal.

[0097] In this embodiment, the model aims to comprehensively consider the multi-physics effects involved in laser cutting, including optical, mechanical (thermal deformation), and fluid (auxiliary gas) effects, and to convert the deviations caused by these effects into compensations for the original machining path through reverse calculation. Its core lies in quantifying the influence of various physical phenomena on the cutting point using mathematical algorithms and generating corrected machine tool motion commands. This model can be implemented as a high-level algorithm module within a CNC system, for example, by performing complex numerical calculations through an embedded processor, or by making real-time compensation decisions through a pre-trained machine learning model. Alternatively, high-speed parallel computing can be achieved using dedicated hardware accelerators, such as FPGAs or ASICs, to meet the requirements of real-time interpolation.

[0098] Final 3D execution coordinates This refers to the three-dimensional spatial coordinate commands actually received and executed by the CNC machine tool servo system after multiphysics compensation. These coordinates ensure that the laser focus can accurately fall on the target cutting position, even if there is thermal deformation on the workpiece surface or a shift in the laser focus. These coordinates are usually sent to the CNC machine tool in the form of G-code, or directly transmitted to the servo driver as position commands via a high-speed bus.

[0099] Original theoretical three-dimensional coordinate vector This vector represents the ideal cutting point location determined based on the 3D model of the blower's metal mesh cover and the designed cutting path, without considering any physical effects (such as thermal deformation or focus shift). This vector is typically generated by CAD / CAM software and input into the cutting system as initial machining path data.

[0100] thermoelastic-plastic deformation This refers to the displacement along the normal direction of the mesh surface caused by thermal expansion and plastic deformation of the material during laser cutting. This deformation is calculated using the thermal buckling mapping model in the preceding steps and reflects the actual geometric changes of the workpiece under thermal action.

[0101] Rayleigh length of laser beam This is an inherent parameter of a laser optical system, characterizing the axial distance at which the laser beam maintains good collimation near the focal point. It determines the depth of the laser beam in the focal region, i.e., the focal depth. This parameter is typically provided by the laser manufacturer and can be preset in the cutting system's parameter library.

[0102] Local normalized normal vector of surface This represents the unit normal vector of the metal mesh surface at the current interpolation point, perpendicular to the surface. It is used to determine the compensation direction, ensuring that the compensation amount is applied along the most direct deformation direction of the workpiece surface.

[0103] Cutting head spindle direction vector This represents the unit direction vector of the laser cutting head at the current interpolation point, indicating the incident direction of the laser beam. Its inner product with the surface normal vector is used to calculate the tilt angle of the laser beam relative to the surface, which in turn affects the projection of the effective Rayleigh length.

[0104] A smart laser cutting device for a hair dryer metal mesh cover, applied to the above-mentioned method, includes:

[0105] The data acquisition module is used to acquire 3D model data, initial processing trajectory, laser power, and beam waist radius;

[0106] The power density calculation module is used to normalize the cutting head's main axis direction vector and the surface normal vector, construct a beam energy coupling distortion model, and output the effective laser power density.

[0107] The thermal deformation calculation module is used to calculate the transient cumulative temperature rise based on the Green's function thermal integral model and substitute it into the thermal buckling mapping model to output the thermoelastic-plastic deformation.

[0108] The air pressure compensation module is used to introduce the deformation and local porosity, construct a dynamic pressure leakage compensation model, and output servo air pressure compensation commands.

[0109] The coordinate compensation module is used to superimpose the focus offset with the deformation vector, output the compensated three-dimensional execution coordinates, and send them to the CNC servo system.

[0110] In this embodiment, the data acquisition module is configured to extract in real time the 3D model data of the blower's metal mesh cover, the initial processing trajectory of the cutting head, the basic emission power of the laser, and the beam waist radius of the laser beam, providing basic parameter inputs for subsequent multiphysics coupling calculations. The power density calculation module normalizes the cutting head's main axis direction vector and the local surface normal vector at the current interpolation point, constructing a beam energy coupling distortion model based on the spatial dynamic tilt angle. This effectively solves the problem of increased spot area and power density attenuation caused by surface tilt, ensuring uniform heat input to micro-holes in different regions. The thermal deformation calculation module, based on the Green's function's discrete-time thermal integral model of moving bodies, uses the set of spatial coordinates of the historically cut micro-hole array and the laser dwell time of a single hole as input parameters. It accurately quantifies the transient cumulative temperature rise and substitutes it into the thermal buckling mapping model, outputting the thermo-elastic-plastic deformation of the thin-walled mesh cover surface along the surface normal, thereby compensating for the positioning reference offset caused by the thermal accumulation effect in dense micro-hole processing.

[0111] Building upon this foundation, the air pressure compensation module incorporates the thermo-elastic-plastic deformation output from the thermal deformation calculation module and the local porosity within the neighborhood of the current cutting point to construct an aerodynamic dynamic pressure leakage compensation model coupled with the hollowing-out leakage effect. This model dynamically calculates the coupled influence of nozzle overhang height fluctuations and porosity on the air pressure field, outputting servo air pressure compensation commands to counteract the leakage effect of gas from the hollowing-out holes, ensuring that the target air pressure is maintained at the cutting front edge to effectively remove molten slag. The coordinate compensation module then vector-superimposes the spatial focus offset based on geometric optics theory with the thermo-elastic-plastic deformation to construct a strongly coupled optomechanical-fluidic multiphysics inverse compensation interpolation model, outputting the final three-dimensional execution coordinates after offset compensation along the locally normalized normal vector direction of the curved surface. After execution by the CNC machine tool servo system, these coordinates can simultaneously correct the focus deviation caused by surface deformation and the theoretical position deviation, achieving dynamic and precise control of the laser beam focusing position.

[0112] Through the above technical solution, the device of this application achieves closed-loop compensation for multi-physics field effects during the laser cutting of metal mesh covers by a hair dryer. The power density calculation module ensures energy coupling accuracy, the thermal deformation calculation module traces historical thermal effects and predicts deformation, the gas pressure compensation module dynamically adjusts gas pressure to adapt to the hollow structure, and the coordinate compensation module completes the coordinated correction of the focal point and deformation. Compared to the limitations of isolated processing of single physical fields in existing technologies, this embodiment, through modular integrated design, incorporates optical, thermodynamic, and fluid dynamic effects into a unified compensation framework, significantly improving the micro-hole processing quality and consistency of complex curved thin-walled mesh covers, and effectively solving the systemic technical challenges pointed out in the background art.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A smart laser cutting method for a metal mesh cover of a hair dryer, characterized in that, Includes the following steps: Step S1: Extract the 3D model data of the blower's metal mesh cover, the initial processing trajectory of the cutting head, the basic emission power of the laser, and the beam waist radius of the laser beam; The cutting head's main axis direction vector and the local surface normal vector at the current interpolation point are normalized to construct a beam energy coupling distortion model based on the spatial dynamic tilt angle, and the effective laser power density at the current interpolation point is output. Step S2: Extract the material physical property parameters of the metal mesh cover, the set of spatial coordinates of the historically cut micro-hole array, and the laser dwell time of a single hole; Using the effective laser power density as a heat source parameter, a discrete-time thermal integral model of the moving body based on the Green's function is constructed to calculate the transient cumulative temperature rise at the current interpolation point; and the transient cumulative temperature rise is substituted into the thermal buckling mapping model to output the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal of the curved surface. Step S3: Extract the auxiliary gas nozzle outlet diameter, ideal nozzle overhang height, free diffusion half angle of the gas jet, local porosity in the neighborhood of the current cutting point, and target air pressure at the cutting front; introduce the thermo-elastic-plastic deformation into the jet dispersion evolution equation, construct an aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect, and output a servo air pressure compensation command to offset the air pressure leakage and the actual nozzle height fluctuation; Step S4: Extract the Rayleigh length of the laser beam and the original theoretical three-dimensional coordinate vector of the current interpolation point; vector superposition the spatial focus offset based on geometric optics theory with the thermo-elastic-plastic deformation to construct an optomechanical-flow multi-physics field strong coupling inverse compensation interpolation model, output the final three-dimensional execution coordinates after offset compensation along the local normalized normal vector direction of the surface, and send them to the CNC laser processing servo system for cutting.

2. The method according to claim 1, characterized in that, In step S1, the specific method for normalizing the cutting head spindle direction vector and the local surface normal vector at the current interpolation point is as follows: calculate the magnitude of the original normal vector and the magnitude of the original direction vector at the current interpolation point respectively; divide the original normal vector by the magnitude to obtain the normalized unit normal vector; divide the original direction vector by the magnitude of the original direction vector to obtain the normalized unit direction vector.

3. The method according to claim 2, characterized in that, In step S1, the specific method for constructing the beam energy coupling distortion model based on the spatial dynamic tilt angle and outputting the effective laser power density at the current interpolation point is as follows: First, calculate the power density baseline by dividing the base emission power of the laser by pi and the square of the laser beam waist radius; then calculate the dot product of the normalized unit normal vector and the normalized unit direction vector to obtain the tilt angle coupling factor. Multiply the power density reference value by the tilt angle coupling factor to obtain the effective laser power density; The calculation is valid only if the dot product value is greater than zero. If the dot product value is less than or equal to zero, the interpolation point is determined to be unreachable and the processing of that point is skipped.

4. The method according to claim 3, characterized in that, In step S2, the specific method for constructing the discrete-time thermal integral model of the moving body based on the Green's function and calculating the transient cumulative temperature rise at the current interpolation point is as follows: All previously cut holes are summed, and the following calculations are performed for each historical hole: The first step is to multiply the effective laser power density at the historical aperture by the product of pi and the square of the laser beam waist radius, and then multiply by the laser dwell time of a single aperture to obtain the total energy of the pulse heat source of a single aperture. Then multiply by the absorptivity constant of the mesh material to the laser to obtain the effective heat source energy actually absorbed by the material. The second step is to first calculate the density of the mesh material and multiply it by the specific heat capacity of the mesh material to obtain the volumetric heat capacity. Then, calculate the product of four times pi, the thermal diffusivity of the mesh material, and the time interval between the historical hole and the current hole. Then, take the cube of 2 of the product and finally multiply the cube of 2 result by the volumetric heat capacity to obtain the heat capacity-diffusion coupling denominator. The third step is to calculate the square of the spatial Euclidean distance between the historical hole center and the current hole center, divide it by the product of four times the thermal diffusivity and the time interval, take the negative value of the quotient, and calculate the exponential function value with the natural constant e as the base to obtain the spatial thermal diffusivity attenuation factor. The fourth step is to divide the effective heat source energy mentioned in the first step by the denominator term of the heat capacity-diffusion coupling mentioned in the second step, and then multiply it by the spatial heat diffusion attenuation factor mentioned in the third step to obtain the temperature rise contribution value of the historical hole to the current hole. The transient cumulative temperature rise at the current interpolation point is obtained by summing the temperature rise contributions of all historical holes.

5. The method according to claim 4, characterized in that, In step S2, the specific method for substituting the transient cumulative temperature rise into the thermal buckling mapping model and outputting the thermo-elastic-plastic deformation of the thin-walled mesh surface along the normal direction of the curved surface is as follows: First, calculate the ratio obtained by dividing the transient cumulative temperature rise by the melting point temperature of the mesh material, take the hyperbolic tangent function value of this ratio, and obtain the thermal buckling modulation factor; then calculate the unsupported local span of the mesh in the current region, multiply it by the linear thermal expansion coefficient, and then multiply it by the transient cumulative temperature rise to obtain the basic thermal expansion; multiply the basic thermal expansion by the thermal buckling modulation factor to obtain the thermo-elastic-plastic deformation along the normal direction of the curved surface.

6. The method according to claim 5, characterized in that, In step S3, the specific method for constructing the aerodynamic dynamic pressure leakage compensation model coupled with the hollow leakage effect and outputting the air pressure compensation command is as follows: The first step is to calculate the dot product of the normalized unit normal vector and the unit vector in the nozzle axis direction to obtain the direction projection factor. Then, multiply the direction projection factor by the thermo-elastic-plastic deformation along the surface normal to obtain the actual deformation along the nozzle axis direction. The second step is to first calculate the difference between the nozzle overhang height under ideal conditions and the actual deformation along the nozzle axis, then multiply it by the tangent of twice the free diffusion half angle of the gas jet to obtain the diffusion radius increment, and then add the diffusion radius increment to the nozzle outlet diameter to obtain the effective diameter of the jet after diffusion. The third step is to divide the effective diameter by the nozzle outlet diameter, and then square the ratio to obtain the jet compression ratio correction term. The fourth step is to subtract the local porosity from the difference, and then take the negative cube of the difference to obtain the leakage correction factor. The fifth step is to multiply the effective air pressure at the target cutting front by the jet compression ratio correction term and then by the leakage correction factor to obtain the servo air pressure compensation command value at the current interpolation point.

7. The method according to claim 6, characterized in that, In step S4, the specific method for constructing the optomechanical flow multiphysics field strongly coupled inverse compensation interpolation model and outputting the final three-dimensional execution coordinates is as follows: First, calculate the dot product of the normalized unit normal vector and the normalized unit direction vector to obtain the tilt angle projection factor. Then, multiply the tilt angle projection factor by the Rayleigh length of the laser beam to obtain the optical focus offset component along the surface normal. Adding the thermo-elastic-plastic deformation along the normal direction of the surface to the optical focus offset component yields the total compensation offset along the normal direction. Then multiply the total compensation offset by the normalized unit normal vector to obtain the three-dimensional compensation offset vector; finally, add the original theoretical three-dimensional coordinate vector of the current interpolation point to the three-dimensional compensation offset vector to obtain the final three-dimensional execution coordinate vector after multiphysics compensation.

8. A smart laser cutting device for a hair dryer metal mesh cover, applied to the method described in claims 1 to 7, characterized in that, include: The data acquisition module is used to acquire 3D model data, initial processing trajectory, laser power, and beam waist radius; The power density calculation module is used to normalize the cutting head's main axis direction vector and the surface normal vector, construct a beam energy coupling distortion model, and output the effective laser power density. The thermal deformation calculation module is used to calculate the transient cumulative temperature rise based on the Green's function thermal integral model and substitute it into the thermal buckling mapping model to output the thermoelastic-plastic deformation. The air pressure compensation module is used to introduce the deformation and local porosity, construct a dynamic pressure leakage compensation model, and output servo air pressure compensation commands. The coordinate compensation module is used to superimpose the focus offset with the deformation vector, output the compensated three-dimensional execution coordinates, and send them to the CNC servo system.

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