In-situ laser-assisted regulation method and device for high-steep free-form surface machining

Abstract

The application belongs to the technical field of laser-assisted machining in aerospace, and relates to an in-situ laser-assisted regulation method and device for high-steepness free-form surface machining. A total reflection critical discrimination function is constructed through the rake angle, relief angle, optical material, laser incidence surface inclination angle of a target tool and the wavelength of a flat-top laser beam. The target laser incidence surface inclination angle of the target tool that does not meet the total reflection critical condition is obtained through the total reflection critical discrimination function. Then, an improved tool with a larger laser emission regulation interval can be obtained on the basis of the target tool, so that the problem of laser emission obstruction in the steepness edge region can be solved. The displacement offset of the target tool is obtained through the derivative function of the curved surface equation of the workpiece to be cut and the optical path difference when the flat-top laser beam is emitted from the cutting point and the center point of the arc. Then, the position of the laser can be regulated in real time, so that the focal point of the flat-top laser beam and the cutting point can follow in real time, thereby improving the machining precision of the target tool on the high-steepness free-form surface workpiece.

Description

Technical Field

[0001] This application belongs to the field of laser-assisted processing technology in aerospace, and more specifically, relates to an in-situ laser-assisted control method and device for processing high-steep freeform surfaces. Background Technology

[0002] In aerospace optical systems, the application of highly steep freeform surfaces, such as off-axis aspherical mirrors, freeform windows, and conformal fairings, is becoming increasingly widespread. These applications place extremely stringent demands on machining accuracy, surface integrity, and subsurface damage. Ultra-precision single-point diamond cutting is one of the core machining methods for these components. To suppress brittle fracture during machining of commonly used hard and brittle materials in aerospace applications, such as silicon carbide, fused silica, and single-crystal silicon, reduce cutting forces, improve surface quality, and minimize subsurface damage, laser-assisted cutting technology has been introduced. This technology improves the material removal mechanism and achieves plastic domain cutting by pre-heating or real-time heating the cutting area.

[0003] However, existing laser-assisted machining methods have three main drawbacks: First, the Gaussian beam output from traditional lasers exhibits a non-uniform energy distribution, with strong energy at the center and weak energy at the edges. This results in an uneven temperature field in the heated area of ​​the workpiece, causing localized thermal deformation and deterioration of surface accuracy when machining large-diameter mirrors. Furthermore, when the cutting point between the target tool and the workpiece surface continuously changes according to the surface equation, the laser focus cannot coincide with the cutting point, making it difficult to achieve consistency in spot size and power density at different cutting points, potentially reducing machining accuracy. Second, in conventional flank-faced emission structures, when the angle between the cutting point and the center of the target tool is too large, the laser incident angle exceeds the critical total internal reflection angle of the tool material-air interface. This causes the laser to undergo total internal reflection inside the target tool and fail to exit, limiting the controllable range of the laser. This problem is particularly prominent when machining large off-axis areas and steep edge regions of mirrors, potentially causing some cutting points to lose laser assistance and thus damaging the workpiece. Third, when machining steep curved surfaces, changes in the position of the cutting point cause the laser irradiation point to deviate from the cutting area. When existing methods adjust the laser position to coincide with the cutting point, the optical path of the laser inside the target tool changes accordingly, which can easily cause fluctuations in the spot size and power density at the cutting point, resulting in uncontrollable heating conditions and directly affecting the surface accuracy and surface roughness. Summary of the Invention

[0004] To address the aforementioned deficiencies in existing technologies, this application provides an in-situ laser-assisted control method and apparatus for machining high-steep freeform surfaces, thereby solving the following technical problems in the prior art: 1. The uneven energy distribution of the Gaussian beam output by the laser leads to an uneven temperature field in the heating zone of the workpiece to be cut, causing local thermal deformation and deterioration of surface accuracy; 2. Under conventional back face emission structures, the laser control range is limited. When the angle between the cutting point and the center of the target tool is too large, the laser incident angle exceeds the critical total reflection angle, causing the laser to fail to exit; 3. When machining high-steep curved surfaces, the position of the cutting point changes, causing the focal point of the laser beam to deviate from the actual cutting point.

[0005] In a first aspect, this application provides an in-situ laser-assisted control method for machining high-steep freeform surfaces, comprising: S1. The Gaussian beam emitted by the laser and directed towards the target tool is shaped by the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution. The focal point of the flat-top laser beam coincides with the center point of the arc of the target tool. S2. Based on the geometry and optical materials of the target tool, as well as the tilt angle of the laser incident surface between the target tool and the flat-top laser beam and the wavelength of the flat-top laser beam, determine whether the target tool meets the critical condition for total internal reflection. S3. When the target tool meets the critical condition of total reflection, obtain the surface equation of the workpiece to be cut corresponding to the target tool, and based on the derivative function of the surface equation and the feed direction of the workpiece to be cut, obtain the horizontal displacement offset between the cutting point of the target tool and the center point of the arc. S4. Based on the geometry of the target tool, the optical material, and the tilt angle of the laser incident surface, obtain the vertical displacement offset between the cutting point of the target tool and the center point of the arc. S5. Based on the horizontal and vertical displacement offsets, generate the displacement signal corresponding to the piezoelectric ceramic displacement platform, and adjust the spatial position of the laser on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

[0006] Furthermore, step S1 includes: Based on the initial spot radius and initial energy distribution of the Gaussian beam emitted by the laser, the target spot radius and target energy distribution of the flat-top laser beam corresponding to the Gaussian beam are obtained through the ray mapping function. Based on the initial spot radius, initial energy distribution, target spot radius, and target energy distribution, the target aspherical coefficient corresponding to the ray mapping function is obtained through a reverse ray tracing algorithm. An aspherical lens that meets the target aspherical coefficient requirement is then fabricated using a lens processing device, serving as the target aspherical lens.

[0007] Further, step S2 includes: Based on the geometry of the target tool, the rake angle and clearance angle of the target tool for cutting the workpiece are obtained. Based on the optical refraction relationship between the rake angle, clearance angle, optical material of the target tool, wavelength of the flat-top laser beam, and the laser incident surface tilt angle between the target tool and the flat-top laser beam, it is determined whether the target tool meets the critical condition for total internal reflection.

[0008] Furthermore, determining whether the target tool satisfies the critical condition for total internal reflection includes: Based on the refractive index of the optical material of the target tool, the wavelength of the flat-top laser beam and the refractive index of air, the critical incident angle for total internal reflection of the target tool is obtained; Based on the critical relationship between the critical incident angle of total internal reflection and the front cutting angle, back cutting angle, and laser incident surface tilt angle, a critical discrimination function for total internal reflection is constructed, and the target tool is judged to meet the critical condition of total internal reflection based on the critical discrimination function for total internal reflection.

[0009] Furthermore, the expression for the critical discriminant function for total internal reflection is:

[0010]

[0011] in, For the front blade angle, For the back angle, The angle of the laser incident surface. This is the critical incident angle for total internal reflection. The refractive index of air, The refractive index of the optical material of the target cutting tool.

[0012] Furthermore, prior to step S3, the following steps are also included: When the target tool does not meet the critical condition for total internal reflection, the tilt angle of the target laser incident surface is obtained based on the critical incident angle and the critical discrimination function for total internal reflection, the front tool angle, and the back tool angle. Based on the negative value of the tilt angle of the target laser incident surface, the geometry of the target tool, and the optical material, a new tool is processed by a tool processing device to replace the target tool.

[0013] Furthermore, the horizontal displacement offset between the cutting point of the target tool and the center point of the arc is obtained, including: Based on the derivative function of the surface equation, the slope of the target tool at each cutting point is obtained, and based on the slope at each cutting point and the feed direction of the workpiece to be cut, the angle between the center point of the arc and each cutting point is obtained. Based on the angle between the center point of the arc and each cutting point, and the arc radius of the target tool, the horizontal offset of the cutting point and the center point of the arc along the feed direction is obtained.

[0014] Furthermore, based on the geometry of the target tool, the optical material, and the tilt angle of the laser incident surface, the vertical displacement offset between the cutting point of the target tool and the center point of the arc is obtained, including: Based on the geometry, optical materials, and laser incident surface tilt angle of the target tool, the optical path difference between the flat-top laser beam emitted from the cutting point and the center point of the arc of the target tool is obtained, and the vertical displacement offset between the cutting point and the center point of the arc is obtained based on the optical path difference.

[0015] In a second aspect, this application also provides an in-situ laser-assisted control device for machining high-steep freeform surfaces, used to perform any of the methods in the first aspect, including: The beam shaping module is used to shape the Gaussian beam emitted by the laser and directed toward the target tool through the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution. The total internal reflection critical condition judgment module is used to determine whether the target tool meets the total internal reflection critical condition based on the target tool's geometry, optical materials, laser incident surface tilt angle between the target tool and the flat-top laser beam, and the wavelength of the flat-top laser beam. The tool replacement module is used to replace the target tool when the target tool does not meet the critical condition for total internal reflection. Based on the critical incident angle of total internal reflection, the critical discrimination function of total internal reflection, the front tool angle, and the back tool angle, the module obtains the tilt angle of the target laser incident surface and, based on the negative value of the tilt angle of the target laser incident surface, the geometry of the target tool, and the optical material, the module processes a new tool through a tool processing device. The horizontal displacement offset acquisition module is used to acquire the surface equation of the workpiece to be cut corresponding to the target tool when the target tool meets the critical condition of total reflection, and to acquire the horizontal displacement offset between the cutting point of the target tool and the center point of the arc based on the derivative function of the surface equation and the feed direction of the workpiece to be cut. The vertical displacement offset acquisition module is used to acquire the vertical displacement offset between the cutting point and the center point of the arc of the target tool based on the geometry of the target tool, the optical material and the tilt angle of the laser incident surface. The laser position adjustment module is used to generate a displacement signal corresponding to the piezoelectric ceramic displacement platform based on the horizontal and vertical displacement offsets, and to adjust the spatial position of the laser set on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

[0016] Thirdly, this application also provides an electronic device, comprising: at least one memory for storing a program; and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute any of the methods of the first aspect.

[0017] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art: 1. This application obtains a corresponding target aspherical lens based on the spot radius and energy distribution of a Gaussian beam to reshape the energy-dispersed Gaussian beam into a flat-top laser beam with uniform energy distribution. This effectively ensures consistent heating in the cutting area and reduces micro-cracks and surface accuracy deterioration caused by local overheating of the workpiece. 2. By considering the rake angle, clearance angle, optical material, laser incident surface tilt angle, and wavelength of the flat-top laser beam of the target tool, a total internal reflection critical discriminant function is constructed. This function is then used to obtain the target laser incident surface tilt angle of the target tool that does not meet the total internal reflection critical condition. This allows for the acquisition of an improved tool with a larger laser emission control range based on the target tool, thereby solving the problem of laser emission obstruction in steep edge regions. 3. By using the derivative function of the surface equation of the workpiece to be cut and the feed direction, the horizontal displacement offset between the cutting point and the center point of the arc is obtained. By using the optical path difference when the flat-top laser beam is emitted from the cutting point and the center point of the arc of the target tool, the vertical displacement offset between the cutting point and the center point of the arc is obtained. Then, the position of the laser can be adjusted in real time by using the horizontal and vertical displacement offsets, so that the focus of the flat-top laser beam follows the cutting point in real time, thereby improving the machining accuracy of the target tool on high-steep free-form surface workpieces. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of the in-situ laser-assisted control method for machining high-steep freeform surfaces provided in the embodiments of this application.

[0020] Figure 2 This is a schematic diagram of a laser-assisted processing machine tool provided in an embodiment of this application.

[0021] Figure 3 This is a schematic diagram of the Gaussian beam shaping principle provided in the embodiments of this application.

[0022] Figure 4 This is a schematic diagram comparing the beam paths within target cutting tools with different geometries provided in the embodiments of this application.

[0023] Figure 5 This is a schematic diagram showing the change in the focal position of the flat-top laser beam when processing a high-steep freeform surface, as provided in the embodiments of this application.

[0024] Figure 6 This is a schematic diagram of the in-situ laser-assisted control device provided in the embodiments of this application.

[0025] Figure 7 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0026] Among them, 101-Gaussian beam; 102-Aspherical lens; 103-Flat-top laser beam; 201-Machine tool displacement stage; 202-Laser; 203-Laser holder; 204-Piezoelectric ceramic displacement platform; 205-Lens holder. Detailed Implementation

[0027] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0028] In the following description, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The following description provides multiple embodiments of this application, which can be substituted or combined with each other. Therefore, this application can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0029] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of this application. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0030] like Figure 1 As shown in the embodiments of this application, the in-situ laser-assisted control method for machining high-steep freeform surfaces includes at least the following steps: S1. The Gaussian beam emitted by the laser and directed towards the target tool is shaped by the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution.

[0031] In this embodiment, the focal point of the flat-top laser beam coincides with the center point of the arc of the target tool. That is, the center point of the arc is assumed to be the cutting point when machining a non-highly steep curved surface of the workpiece, and the flat-top laser beam is used to soften the machining area at the cutting point. Figure 2As shown, the laser-assisted machining machine tool used in this application includes a machine tool displacement stage 201, a laser 202, a laser holder 203, a piezoelectric ceramic displacement platform 204, and a lens holder 205. The laser holder 203 is used to fix the laser 202, and the lens holder 205 is used to fix the aspherical lens 102. The laser holder 203 is connected to the piezoelectric ceramic displacement platform 204, and thus, under the drive of the piezoelectric ceramic displacement platform 204, it can move horizontally or vertically along the feed direction of the workpiece to be cut. Simultaneously, it can also drive the laser 202 to move, thereby changing the focal position of the flat-top laser beam irradiating the target tool. The Gaussian beam emitted by the laser 202 passes through the aspherical lens 102 and is directed towards the cutting point of the target tool. The aspherical lens 102 reshapes the Gaussian beam to obtain a flat-top laser beam.

[0032] In one possible implementation, step S1 includes: Based on the initial spot radius and initial energy distribution of the Gaussian beam emitted by the laser, the target spot radius and target energy distribution of the flat-top laser beam corresponding to the Gaussian beam are obtained through the ray mapping function. Based on the initial spot radius, initial energy distribution, target spot radius, and target energy distribution, the target aspherical coefficient corresponding to the ray mapping function is obtained through a reverse ray tracing algorithm. An aspherical lens that meets the target aspherical coefficient requirement is then fabricated using a lens processing device, serving as the target aspherical lens.

[0033] In the embodiments of this application, such as Figure 3 As shown, the ray mapping function is based on the law of conservation of energy, and its formula is expressed as: ; ; ; ; ; ; in, The input energy represents the Gaussian beam before shaping. This represents the output energy of the flat-top laser beam after shaping. Ideally, the laser experiences no energy loss when passing through the lens; according to the law of conservation of energy... and They should be equal. and These represent the peak values ​​of the energy distributions of the Gaussian beam and the flat-top laser beam, respectively. and The initial spot radius and the target spot radius are represented respectively. and These represent the beam radii of the Gaussian beam and the flat-top laser beam, respectively. It is a variable representing the radius. These are intermediate coefficients used in the formula derivation.

[0034] After obtaining the target aspherical coefficients corresponding to the ray mapping function through the reverse ray tracing algorithm, an initial lens model is established in the simulation software based on the initial spot radius, initial energy distribution, target spot radius, and target energy distribution. The simulation software determines the curvature distribution of the initial lens model based on the target aspherical coefficients. This curvature distribution allows rays at different radial positions of the Gaussian beam 101 to be deflected at different angles when passing through the aspherical lens 102. Rays with higher energy at the center are moderately diverged, while rays with lower energy at the edges are moderately converged, resulting in a flat-top laser beam 103 with approximately uniform energy output. Compared to the traditional Gaussian beam 101, the shaped flat-top laser beam 103 can make the temperature field more uniform within the irradiation area of ​​commonly used hard and brittle materials in aerospace applications such as silicon carbide and fused silica. This effectively suppresses microcracks and surface errors caused by localized thermal shock, improving the consistency of the cutting process and the imaging quality of the final optical surface.

[0035] S2. Based on the geometry and optical materials of the target tool, as well as the tilt angle of the laser incident surface between the target tool and the flat-top laser beam and the wavelength of the flat-top laser beam, determine whether the target tool meets the critical condition for total internal reflection.

[0036] In one possible implementation, step S2 includes: Based on the geometry of the target tool, the rake angle and clearance angle of the target tool for cutting the workpiece are obtained. Based on the optical refraction relationship between the rake angle, clearance angle, optical material of the target tool, wavelength of the flat-top laser beam, and the laser incident surface tilt angle between the target tool and the flat-top laser beam, it is determined whether the target tool meets the critical condition for total internal reflection.

[0037] The determination of whether the target tool meets the critical condition for total internal reflection includes: Based on the refractive index of the optical material of the target tool, the wavelength of the flat-top laser beam and the refractive index of air, the critical incident angle for total internal reflection of the target tool is obtained; Based on the critical relationship between the critical incident angle of total internal reflection and the front cutting angle, back cutting angle, and laser incident surface tilt angle, a critical discrimination function for total internal reflection is constructed, and the target tool is judged to meet the critical condition of total internal reflection based on the critical discrimination function for total internal reflection.

[0038] In this embodiment, the critical angle of incidence for total internal reflection is the maximum angle of incidence that prevents total internal reflection from occurring. It can be determined according to the law of total internal reflection, and its corresponding calculation formula is as follows:

[0039] The optical material of the target cutting tool is diamond. The refractive index of air, The refractive index of diamond is given (related to the optical material and the wavelength of the incident laser beam), while the refractive index of air is generally assumed to be... =1. The transmission of laser light inside the tool is mainly determined by the tool's rake angle, clearance angle, and the angle of incidence of the laser. Based on the fundamental principles of geometric optics, the critical condition for preventing total internal reflection when the laser exits a diamond tool is derived. When the wavelength of the flat-top laser beam is 1070 nm, the refractive index of the diamond tool is 2.39, and the expression for the critical criterion function for total internal reflection is:

[0040]

[0041] in, For the front blade angle, For the back angle, The angle of the laser incident surface. For example... Figure 4 As shown, the optical path of the laser beam within the target tool is illustrated. The optical path of the flat-top laser within the target tool on the left reflects a situation where the rake angle, clearance angle, and laser incident plane tilt angle do not satisfy the constraints of the critical discriminant function for total internal reflection, resulting in total internal reflection of the incident flat-top laser. In this case, the flat-top laser cannot be directed from the cutting point to the workpiece, therefore, it is necessary to change the laser incident plane tilt angle based on the target tool.

[0042] When the target tool does not meet the critical condition for total internal reflection, the target laser incident surface tilt angle is obtained based on the critical incident angle and critical discrimination function for total internal reflection, the rake angle, and the clearance angle. Then, based on the negative value of the target laser incident surface tilt angle, the geometry of the target tool, and the optical material, a new tool is manufactured using a tool processing device to replace the target tool. For example... Figure 4 The optical path of the flat-top laser within the target tool on the right is shown. With the rake angle and clearance angle fixed, the tilt angle of the target laser incident surface can be calculated using the total internal reflection critical discriminant function. Then, a negative value is taken for the tilt angle, and the geometry of the original target tool is improved based on this negative value. This process can be performed in simulation software. Specifically, the target tool is optically modeled, and the optical model of the new tool is obtained using the above method. Finally, the new tool is machined using a tool processing device to replace the original target tool.

[0043] After the above operations, the flat-top laser beam enters the tool from the outside and undergoes a total internal reflection on the bottom surface of the tool. By precisely adjusting the angle of the incident surface, the reflected laser beam is emitted horizontally from the front face of the tool, and the emitted beam maintains good uniformity.

[0044] S3. When the target tool meets the critical condition of total reflection, obtain the surface equation of the workpiece to be cut corresponding to the target tool, and based on the derivative function of the surface equation and the feed direction of the workpiece to be cut, obtain the horizontal displacement offset between the cutting point of the target tool and the center point of the arc.

[0045] S4. Based on the geometry of the target tool, optical materials, and the tilt angle of the laser incident surface, obtain the vertical displacement offset between the cutting point of the target tool and the center point of the arc.

[0046] In one possible implementation, obtaining the horizontal and vertical displacement offsets between the cutting point of the target tool and the center point of the arc includes: Based on the derivative function of the surface equation, the slope of the target tool at each cutting point is obtained, and based on the slope at each cutting point and the feed direction of the workpiece to be cut, the angle between the center point of the arc and each cutting point is obtained. Based on the angle between the center point of the arc and each cutting point, and the arc radius of the target tool, the horizontal offset of the cutting point and the center point of the arc along the feed direction is obtained. Based on the geometry, optical materials, and laser incident surface tilt angle of the target tool, the optical path difference between the flat-top laser beam emitted from the cutting point and the center point of the arc of the target tool is obtained, and the vertical displacement offset between the cutting point and the center point of the arc is obtained based on the optical path difference.

[0047] In the embodiments of this application, such as Figure 5 As shown, in theoretical conditions, the cutting point of the target tool is the center point of its arc. Therefore, the initial focus of the flat-top laser beam coincides with the position of the center point of the target tool's arc. However, when machining high-steep freeform surfaces for aerospace applications, the position of the actual contact point (i.e., the cutting point) between the tool and the workpiece surface on the tool's arc cutting edge changes continuously with the surface morphology and machining path. Therefore, it is necessary to correct the focus position of the flat-top laser beam, i.e., adjust the spatial position of the laser along the workpiece feed direction. Taking the center point of the tool's arc as the reference point, let the radius of the tool's arc be R. First, based on the surface equation of the high-steep freeform surface to be machined and the machining path, the geometric relationship between the surface normal at the cutting point and the tool center is determined by obtaining the derivative function of the surface equation along the machining direction. Then, the angle α between the tool cutting point and the center point of the tool's arc is calculated.

[0048] The relationship between the angle α between the tool cutting point and the tool center and the machining path satisfies the following equation: α=h'(x,y) Where h'(x,y) is the derivative of the angle α between the cutting point and the tool center, and the x and y values ​​in the horizontal and vertical directions of the machining path. Based on this angle α and the tool radius R, the offset of the cutting point relative to the tool center can be calculated, that is, the horizontal displacement of the laser focus in the horizontal x direction:

[0049] At the same time, such as Figure 4 As shown, due to the specific structural dimensions and refractive index of diamond tools, the optical path of the laser beam inside the tool varies depending on the exit point. In this step, it is also necessary to calculate the optical path when the laser exits from the cutting point and the optical path when it exits from the center point of the tool's arc, based on the diamond tool's geometry (rake angle, clearance angle, and target laser incident surface tilt angle) and the refractive index of the optical material. The difference between these two calculations is the optical path difference that needs to be compensated. This optical path difference corresponds to the vertical displacement Δy of the laser focus in the vertical y-direction.

[0050] in, The optical path length emitted from the cutting point. The optical path length emitted from the center point of the arc.

[0051] S5. Based on the horizontal and vertical displacement offsets, generate the displacement signal corresponding to the piezoelectric ceramic displacement platform, and adjust the spatial position of the laser on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

[0052] In the embodiments of this application, such as Figure 2 As shown, the executing entity of this application is the controller of the host computer of the in-situ laser-assisted control device. The host computer is also connected to the piezoelectric ceramic displacement platform 204 by signal. The host computer generates corresponding voltage waveform data according to the horizontal displacement offset and the vertical displacement offset, and generates corresponding analog voltage signal (displacement signal) through the built-in signal generator. Then, the piezoelectric ceramic displacement platform 204 is driven to move horizontally in the x direction and vertically in the y direction along the workpiece feed direction through the displacement signal, thereby changing the focal position of the flat-top laser beam emitted by the laser 202, so that the focal point of the flat-top laser beam coincides with the cutting point of the target tool in real time.

[0053] Figure 6 This is a schematic diagram of the in-situ laser-assisted control device for machining high-steep freeform surfaces provided in the embodiments of this application, as shown below. Figure 6 As shown, the device includes at least: The beam shaping module is used to shape the Gaussian beam emitted by the laser and directed toward the target tool through the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution. The total internal reflection critical condition judgment module is used to determine whether the target tool meets the total internal reflection critical condition based on the target tool's geometry, optical materials, laser incident surface tilt angle between the target tool and the flat-top laser beam, and the wavelength of the flat-top laser beam. The tool replacement module is used to replace the target tool when the target tool does not meet the critical condition for total internal reflection. Based on the critical incident angle of total internal reflection, the critical discrimination function of total internal reflection, the front tool angle, and the back tool angle, the module obtains the tilt angle of the target laser incident surface and, based on the negative value of the tilt angle of the target laser incident surface, the geometry of the target tool, and the optical material, the module processes a new tool through a tool processing device. The horizontal displacement offset acquisition module is used to acquire the surface equation of the workpiece to be cut corresponding to the target tool when the target tool meets the critical condition of total reflection, and to acquire the horizontal displacement offset between the cutting point of the target tool and the center point of the arc based on the derivative function of the surface equation and the feed direction of the workpiece to be cut. The vertical displacement offset acquisition module is used to acquire the vertical displacement offset between the cutting point and the center point of the arc of the target tool based on the geometry of the target tool, the optical material and the inclination angle of the laser incident surface. The laser position adjustment module is used to generate a displacement signal corresponding to the piezoelectric ceramic displacement platform based on the horizontal and vertical displacement offsets, and to adjust the spatial position of the laser set on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

[0054] like Figure 7 As shown, Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: a processor 701, a communications interface 702, a memory 703, and a communication bus 704. The processor 701, communications interface 702, and memory 703 communicate with each other via the communication bus 704. The processor 701 can call software instructions in the memory 703 to execute the methods described in the above embodiments.

[0055] Furthermore, the logical instructions in the aforementioned memory 703 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application.

[0056] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0057] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0058] It is understood that the processor in the embodiments of this application can be a CPU (Central Processing Unit), or other general-purpose processors, DSPs (Digital Signal Processors), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0059] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, ROM (Read-only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), EEPROM (Electrically Erasable EPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0060] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line DSL) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., SSD (Solid State Disk)).

[0061] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0062] Those skilled in the art will readily understand that the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An in-situ laser-assisted control method for machining high-steep freeform surfaces, characterized in that, include: S1. The Gaussian beam emitted by the laser and directed towards the target tool is shaped by the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution. The focal point of the flat-top laser beam coincides with the position of the center point of the arc of the target tool. S2. Based on the geometry and optical materials of the target tool, the laser incident surface tilt angle between the target tool and the flat-top laser beam, and the wavelength of the flat-top laser beam, determine whether the target tool satisfies the critical condition for total internal reflection. S3. When the target tool satisfies the critical condition of total reflection, obtain the surface equation of the workpiece to be cut corresponding to the target tool, and based on the derivative function of the surface equation and the feed direction of the workpiece to be cut, obtain the horizontal displacement offset between the cutting point of the target tool and the center point of the arc. S4. Based on the geometry, optical material, and laser incident surface tilt angle of the target tool, obtain the vertical displacement offset between the cutting point and the center point of the arc of the target tool. S5. Based on the horizontal displacement offset and the vertical displacement offset, generate a displacement signal corresponding to the piezoelectric ceramic displacement platform, and adjust the spatial position of the laser on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

2. The in-situ laser-assisted control method according to claim 1, characterized in that, Step S1 includes: Based on the initial spot radius and initial energy distribution of the Gaussian beam emitted by the laser, the target spot radius and target energy distribution of the flat-top laser beam corresponding to the Gaussian beam are obtained through a ray mapping function. Based on the initial spot radius, initial energy distribution, target spot radius, and target energy distribution, the target aspherical coefficient corresponding to the ray mapping function is obtained through a reverse ray tracing algorithm. An aspherical lens that meets the target aspherical coefficient requirement is then fabricated using a lens processing device, serving as the target aspherical lens.

3. The in-situ laser-assisted control method according to claim 1, characterized in that, Step S2 includes: Based on the geometry of the target tool, the rake angle and clearance angle of the target tool for cutting the workpiece are obtained. Based on the optical refraction relationship between the rake angle, clearance angle, optical material of the target tool, wavelength of the flat-top laser beam, and the laser incident surface tilt angle between the target tool and the flat-top laser beam, it is determined whether the target tool meets the critical condition for total internal reflection.

4. The in-situ laser-assisted control method according to claim 3, characterized in that, The determination of whether the target tool satisfies the critical condition for total internal reflection includes: Based on the refractive index of the optical material of the target tool, the wavelength of the flat-top laser beam and the refractive index of air, the critical incident angle for total internal reflection of the target tool is obtained; Based on the critical relationship between the critical incident angle of total internal reflection and the front cutting angle, back cutting angle, and laser incident surface tilt angle, a critical discrimination function for total internal reflection is constructed, and the target tool is judged to meet the critical condition for total internal reflection based on the critical discrimination function for total internal reflection.

5. The in-situ laser-assisted control method according to claim 4, characterized in that, The expression for the critical discriminant function for total internal reflection is: in, For the front blade angle, For the back angle, The angle of the laser incident surface. This is the critical incident angle for total internal reflection. The refractive index of air, The refractive index of the optical material of the target cutting tool.

6. The in-situ laser-assisted control method according to claim 5, characterized in that, Before step S3, the method further includes: When the target tool does not meet the critical condition for total internal reflection, the target laser incident surface tilt angle is obtained based on the critical incident angle and the critical discrimination function for total internal reflection, the front tool angle, and the back tool angle. Based on the negative value of the target laser incident surface tilt angle, the geometry of the target tool, and the optical material, a new tool is processed by a tool processing device to replace the target tool.

7. The in-situ laser-assisted control method according to claim 1, characterized in that, The step of obtaining the horizontal displacement offset between the cutting point of the target tool and the center point of the arc includes: Based on the derivative function of the surface equation, the slope of the target tool at each cutting point is obtained, and based on the slope at each cutting point and the feed direction of the workpiece to be cut, the angle between the center point of the arc and each cutting point is obtained. Based on the angle between the center point of the arc and each of the cutting points, and the arc radius of the target tool, the horizontal offset of the cutting point and the center point of the arc along the feed direction is obtained.

8. The in-situ laser-assisted control method according to claim 1, characterized in that, The process of obtaining the vertical displacement offset between the cutting point and the center point of the arc of the target tool based on the geometry, optical material, and laser incident surface tilt angle of the target tool includes: Based on the geometry, optical materials, and laser incident surface tilt angle of the target tool, the optical path difference between the flat-top laser beam emitted from the cutting point and the center point of the arc of the target tool is obtained, and the vertical displacement offset between the cutting point and the center point of the arc is obtained based on the optical path difference.

9. An in-situ laser-assisted control device for machining high-steep freeform surfaces, used to perform the method as described in any one of claims 1-8, characterized in that, include: The beam shaping module is used to shape the Gaussian beam emitted by the laser and directed toward the target tool through the target aspherical lens to obtain a flat-top laser beam with uniform energy distribution. The total internal reflection critical condition judgment module is used to determine whether the target tool meets the total internal reflection critical condition based on the geometric structure, optical material, laser incident surface tilt angle between the target tool and the flat-top laser beam, and the wavelength of the flat-top laser beam. The tool replacement module is used to replace the target tool when the target tool does not meet the critical condition for total internal reflection. Based on the critical incident angle of total internal reflection, the critical discrimination function of total internal reflection, the front tool angle, and the back tool angle, the module obtains the tilt angle of the target laser incident surface and, based on the negative value of the tilt angle of the target laser incident surface, the geometry of the target tool, and the optical material, the module processes a new tool through a tool processing device. The horizontal displacement offset acquisition module is used to acquire the surface equation of the workpiece to be cut corresponding to the target tool when the target tool meets the critical condition of total reflection, and to acquire the horizontal displacement offset between the cutting point of the target tool and the center point of the arc based on the derivative function of the surface equation and the feed direction of the workpiece to be cut. The vertical displacement offset acquisition module is used to acquire the vertical displacement offset between the cutting point and the center point of the arc of the target tool based on the geometry, optical material and laser incident surface inclination of the target tool. The laser position adjustment module is used to generate a displacement signal corresponding to the piezoelectric ceramic displacement platform based on the horizontal displacement offset and the vertical displacement offset, and to adjust the spatial position of the laser on the piezoelectric ceramic displacement platform in real time based on the displacement signal.

10. An electronic device, characterized in that, include: At least one memory for storing computer programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-8.

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