Free-form surface-oriented laser-assisted processing light beam self-adaptive regulation and control device and method

Abstract

The invention belongs to the technical field of laser-assisted machining, and relates to a free-form surface-oriented laser-assisted machining beam adaptive regulation and control device and method, and the method comprises the steps: planning a tool path on a free-form surface to be machined, and calculating a curved surface derived function equation; obtaining a deviation value between the actual position center of the contact area of the cutter and the to-be-machined surface and the design position center of the contact area of the cutter and the to-be-machined surface by utilizing the geometric parameters of the cutter and the curved surface derived function equation; calculating a laser beam deflection angle by using the deviation value; the laser spot size and laser power density distribution are obtained through the actual length of the contact area of the tool and the to-be-machined surface; obtaining a laser beam defocusing distance by using the laser spot size and the laser power density distribution; and enabling the laser to rotate along the deflection angle of the laser beam and linearly move along the defocusing distance of the laser beam so as to realize self-adaptive regulation and control of the laser beam. According to the invention, self-adaptive adjustment of the free-form surface full-aperture laser beam can be realized.

Description

Technical Field

[0001] The present application belongs to the field of laser-assisted processing technology, and more specifically, relates to a device and method for adaptively controlling a beam of light for laser-assisted processing of free-form surfaces. Background Art

[0002] Micro-laser-assisted machining is a new micro-nano machining technology that integrates single-point diamond turning. It uses a Gaussian-distributed laser beam to irradiate the cutting area of ​​the workpiece, softening brittle materials (such as single-crystal silicon, tungsten carbide, and fused quartz), improving machining performance and extending tool life. During flat machining, the laser can stably irradiate a constant cutting area. However, during curved surface machining, changes in the slope and curvature of the surface cause the cutting edge position to dynamically shift, and the actual laser irradiation area does not overlap with the theoretical softening area. Because the laser energy has a Gaussian distribution, the center temperature is the highest. This shift can cause insufficient temperature in local areas, triggering brittle fracture, resulting in surface errors and reduced surface quality. In addition, during curved surface machining, the tool feeds from the edge to the center, and the cutting speed at the center is lower than that at the edge. At the same laser power, the center is heated for a longer time and at a higher temperature, resulting in uneven thermal expansion, further affecting machining accuracy. In summary, the existing problems of micro-laser-assisted surface processing technology are: (1) laser irradiation offset, the change of surface geometry causes the laser beam and the cutting area to be misaligned, and the softening effect is uneven; (2) temperature distribution imbalance, the difference in cutting speed causes uneven heat accumulation, affecting the consistency of material removal; (3) thermal deformation, local overheating causes the difference in thermal expansion of the processed surface, reducing the surface accuracy; (4) lack of real-time control, and the laser light path cannot be dynamically adjusted to adapt to the dynamic cutting conditions in surface processing. Summary of the Invention

[0003] In response to the defects of the existing technology, the purpose of this application is to provide a laser-assisted processing beam adaptive control device and method for free-form surfaces, aiming to solve the processing limitations of existing laser-assisted processing devices in free-form surface processing, resulting in the problem that the processed free-form surface optical elements cannot meet the requirements of high-precision optical systems.

[0004] To achieve the above objectives, in a first aspect, the present application provides a method for adaptively controlling a beam in laser-assisted processing of free-form surfaces, comprising: S1 plans the tool path on the free-form surface to be machined and calculates the surface derivative equation; S2 uses the tool geometric parameters and the surface derivative function equation to obtain the deviation between the actual position center of the contact area between the tool and the surface to be processed and the designed position center of the contact area between the tool and the surface to be processed; and uses the deviation to calculate the laser beam deflection angle; S3 obtains the laser spot size and laser power density distribution using the actual length of the contact area between the tool and the surface to be processed; and obtains the laser beam defocus distance using the laser spot size and laser power density distribution; S4 causes the laser to rotate along the laser beam deflection angle and to move linearly along the laser beam defocus distance, so as to achieve adaptive control of the laser beam.

[0005] Furthermore, in step S1, the surface derivative function equation is expressed as: z'=g1(x,y) Among them, z is the surface sag, and g1(x,y) represents the functional relationship between the surface sag z and the surface coordinates (x,y).

[0006] Furthermore, in step S2, the actual position center of the contact area between the tool and the surface to be machined is expressed as: X1=m1(x,y) Among them, X1 is the coordinate of the actual position center along the x direction, and m1 is the functional relationship between the coordinate X of the actual position center and the coordinate (x, y) of the surface processing point; The design position center coordinates of the contact area between the tool and the surface to be machined are expressed as: X2=n1(x,y) Among them, X2 is the coordinate of the design position center along the x direction, and n1 is the functional relationship between the design position center coordinate X and the coordinate (x, y) of the surface processing point; The deviation value is calculated using the following formula: X0=X1-X2 Wherein, X0 is the deviation value.

[0007] Furthermore, in step S2, the laser beam deflection angle is calculated using the following formula: θ=X0 / I Wherein, θ is the deflection angle of the laser beam, X0 is the deviation value, and I is the distance from the laser output end of the laser to the tip of the tool.

[0008] Furthermore, in step S3, the actual length of the contact area between the tool and the surface to be processed is first used to determine the spot radius of the laser beam, and then the Gaussian beam intensity distribution expression is used to calculate the optimal power density distribution of the laser beam corresponding to the spot radius. The Gaussian beam intensity distribution expression is:

[0009] in, I 0 is the beam power density at the center of the Gaussian beam waist, ω ( z ) is the spot radius, ω 0 is the waist radius, z is the surface sag, r is the theoretical Gaussian beam radius, P 0 is the total power of the laser beam.

[0010] Furthermore, in step S3, the laser spot size and laser power density distribution are used to obtain the formula for the laser beam defocus distance:

[0011] in, ω ( z ) is the spot radius, z0 is the laser beam defocus distance, z R is the Rayleigh range; The formula for calculating the Rayleigh range is:

[0012] in, is the laser beam wavelength, is the quality factor of the laser beam, ω 0 is the beam waist radius.

[0013] According to the second aspect of the present application, a device for implementing the laser-assisted processing beam adaptive control method as described in any of the above items is also provided, including: a servo linear displacement unit, a servo angular displacement unit, a laser-assisted processing unit and an external control unit. The laser-assisted processing unit includes a laser, and the external control unit is used to control the servo linear displacement unit to drive the laser to move linearly according to the defocus distance of the laser beam, and is also used to control the servo angular displacement unit to drive the laser to rotate according to the deflection angle of the laser beam, thereby realizing adaptive control of the processing beam.

[0014] Furthermore, it also includes a base plate, on which a focusing mirror, an optical window and a diamond tool are arranged in sequence along the propagation direction of the laser beam. The laser is arranged on the side of the focusing mirror away from the optical window. The servo linear displacement unit is fixed on the base plate and is located directly below the laser. The servo angular displacement unit is arranged between the servo linear displacement unit and the laser.

[0015] According to a third aspect of the present application, there is further provided an apparatus for implementing the laser-assisted processing beam adaptive control method as described in any one of the preceding items, comprising: The machining path planning module is used to plan the tool path on the free-form surface to be machined and calculate the surface derivative function equation; a laser beam deflection angle acquisition module, configured to obtain, using tool geometric parameters and the surface derivative equation, a deviation between the actual position center of the contact area between the tool and the surface to be machined and the designed position center of the contact area between the tool and the surface to be machined; and further configured to calculate the laser beam deflection angle using the deviation; A laser beam defocus distance acquisition module is used to obtain the laser spot size and laser power density distribution using the actual length of the contact area between the tool and the surface to be processed; and is also used to obtain the laser beam defocus distance using the laser spot size and laser power density distribution; The adaptive control module is used to control the laser to rotate along the deflection angle of the laser beam; and is also used to control the laser to move linearly along the defocus distance of the laser beam.

[0016] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0017] In general, the above technical solutions conceived by this application have the following beneficial effects compared with the existing technologies: (1) This application is aimed at laser-assisted processing of free-form surfaces. It uses a linear displacement platform and an angular displacement platform to adaptively control the spatial position of the optical path, so that the processing area is always irradiated by a laser beam with an optimal power density distribution, achieving full-aperture laser beam tracking of the free-form surface. Compared with traditional laser-assisted processing devices and methods, it performs better in full-aperture uniform precision processing of complex surfaces, thereby effectively improving the processing quality of free-form surfaces.

[0018] (2) This application greatly optimizes the heat-affected zone of free-form surface processing, reduces the area of ​​the processed surface irradiated by laser, and suppresses its thermal expansion, thereby effectively improving the processing quality of the free-form surface.

[0019] (3) This application achieves collaborative multi-objective optimization of power-rate matching and laser position by establishing open-loop control between the surface equation and the spatial position of the laser beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 1 is a flow chart of a method for adaptively controlling a beam in laser-assisted machining of free-form surfaces, provided in Example 1 of the present application; Figure 2 This is a schematic diagram of the principle of the method for adaptively controlling the beam in laser-assisted processing of free-form surfaces provided in Example 1 of the present application; Figure 3 This is provided in Example 1 of the present application. Figure 2 A partial schematic diagram of the corresponding principle of the adaptive control method; Figure 4Schematic diagram of the structure of the device for implementing the method for adaptively controlling the laser-assisted processing beam provided in Example 2 of the present application; Figure 5 This is a partial structural diagram of the method for implementing adaptive control of laser-assisted processing beams provided in Example 2 of the present application.

[0021] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-Servo linear displacement unit; 2-Servo angular displacement unit, 3-Laser, 4-Base plate, 5-Focusing mirror, 6-Optical window, 7-Diamond tool, 8-Adapter plate, 9-Laser support seat, 10-Laser pressure cover, 11-Focusing mirror support seat, 12-Optical window support seat, 13-Optical window pressure cover, 14-Diamond tool holder. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0023] The term "and / or" as used herein describes an association between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. The symbol " / " as used herein indicates that the related objects are in an "or" relationship, for example, A / B means either A or B.

[0024] The terms "first" and "second" in this specification and claims are used to distinguish different objects rather than to describe a specific order of objects. For example, "first response message" and "second response message" are used to distinguish different response messages rather than to describe a specific order of response messages.

[0025] In the embodiments of this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0026] In the description of the embodiments of the present application, unless otherwise specified, "multiple" means two or more, for example, multiple processing units means two or more processing units, etc.; multiple elements means two or more elements, etc.

[0027] In order to meet the processing requirements of complex optical components made of brittle materials, this application designs a more advanced real-time adaptive control method and system for laser-assisted processing optical paths to automatically focus the center of the laser beam on the cutting center, thereby improving the processing performance of brittle materials and achieving high-precision processing of curved optical components.

[0028] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0029] Example 1 This embodiment provides a method for adaptively controlling the beam in laser-assisted processing of free-form surfaces. Figure 1 As shown, the following steps are included: S1 plans the tool path on the free-form surface to be machined and calculates the surface derivative equation; S2 uses the tool geometric parameters and the surface derivative function equation to obtain the deviation between the actual position center of the contact area between the tool and the surface to be processed and the designed position center of the contact area between the tool and the surface to be processed; and uses the deviation to calculate the deflection angle of the laser beam; S3 uses the actual length of the contact area between the tool and the surface to be processed to obtain the laser spot size and laser power density distribution; and uses the laser spot size and laser power density distribution to obtain the laser beam defocus distance; S4 rotates the laser along the laser beam deflection angle and moves linearly along the laser beam defocus distance to achieve adaptive control of the laser beam.

[0030] In the aforementioned step S1, the surface derivative function equation is expressed as: z'=g1(x,y) Among them, z is the surface sag, and g1(x,y) represents the functional relationship between the surface sag z and the surface coordinates (x,y).

[0031] In the aforementioned step S2, the actual position center of the contact area between the tool and the surface to be machined is expressed as: X1=m1(x,y) Among them, X1 is the coordinate of the actual position center along the x direction, and m1 is the functional relationship between the coordinate X of the actual position center and the coordinate (x, y) of the surface processing point; The design position center coordinates of the contact area between the tool and the surface to be machined are expressed as: X2=n1(x,y) Among them, X2 is the coordinate of the design position center along the x direction, and n1 is the functional relationship between the design position center coordinate X and the coordinate (x, y) of the surface processing point; The deviation value is calculated using the following formula: X0=X1-X2 Among them, X0 is the deviation value.

[0032] In step S2, the laser beam deflection angle is calculated using the following formula: θ=X0 / I Where θ is the deflection angle of the laser beam, and I is the distance from the laser output end to the tip of the tool.

[0033] In step S3, the actual length of the contact area between the tool and the surface to be processed is first used to determine the spot radius of the laser beam. Then, the Gaussian beam intensity distribution expression is used to calculate the optimal power density distribution of the laser beam corresponding to the spot radius. The Gaussian beam intensity distribution expression is:

[0034] in, I 0 is the beam power density at the center of the Gaussian beam waist, ω ( z ) is the spot radius, ω 0 is the waist radius, z is the surface sag, r is the theoretical Gaussian beam radius, P 0 is the total power of the laser beam.

[0035] In step S3, the laser spot size and laser power density distribution are used to obtain the formula for the laser beam defocus distance:

[0036] in, ω ( z ) is the spot radius, z0 is the laser beam defocus distance, z R is the Rayleigh range; The formula for calculating the Rayleigh range is:

[0037] in, is the laser beam wavelength, M 2 is the quality factor of the laser beam.

[0038] The principle diagram of adaptive control using the above method is as follows: Figure 2 As shown, Figure 2 Figure a is a schematic diagram of the processing principle of the existing laser-assisted processing method designed only for plane cutting, and Figures c~d are schematic diagrams of the laser-assisted processing principle designed according to the method of this application. Figure 2 In the middle figures a~d, the blank arc-shaped closed figure A between the solid line and the dotted line on the left represents the position of the Nth tool during the machining process along the feed direction, and the shadow-filled arc-shaped closed figure B between the solid line and the dotted line on the right represents the position of the N+1th tool during the machining process. The cutting height a in each figure isp The shaded areas between the solid line and the boundary are the nominal cutting area (i.e., the designed cutting area) and the actual cutting area, respectively. Figure 2 In the equation, f represents the feed rate, a p Represents the cutting depth, l plane Represents the nominal cutting area width, l surface Represents the actual cutting area width.

[0039] like Figure 3 As shown, Figure 3 Figure a is with Figure 2 The schematic diagram of the plane cutting laser position corresponding to Figure a shows that in the traditional plane machining process, the contact area between the diamond tool cutting edge and the workpiece remains constant. By adjusting the laser emission position, the laser can be effectively irradiated in the material cutting area during the entire machining process. Through the plane cutting process shown, the nominal cutting area width l is calculated. plane And the nominal cutting area center position coordinate X2 (i.e. the design position center coordinate of the contact area between the tool and the surface to be machined) provides a data basis for calculating the cutting area center deviation value.

[0040] Figure 3 Figure b is with Figure 2 The uncontrolled curved surface cutting laser position corresponding to Figure b shows that during the curved surface machining process, the contact area between the diamond tool cutting edge and the workpiece is obviously inconsistent with that during the flat surface machining process (the red dotted line and the blue dotted line do not overlap), and the specific contact area does not completely overlap with the laser irradiation area. The actual offset is determined by the slope and curvature of the surface. Through the curved surface cutting process shown, the actual cutting area width l is calculated. surface And the center position coordinate X1 of the cutting area, and then calculate the center deviation value X0 according to X0=X1-X2. The laser defocus distance and deflection angle are calculated by the center deviation value X0, thereby realizing adaptive control of the laser-assisted processing beam for free-form surfaces.

[0041] Figure 3 Figure c is with Figure 2 The position of the curved surface cutting laser after the defocus distance is adjusted in Figure c, which is used to show the change of the laser irradiation area after adjusting the defocus distance according to the actual offset. As can be seen from the figure, compared with the curved surface cutting laser position when the defocus distance is not adjusted, the red line trapezoidal area representing the laser beam in Figure c is changed after adjusting the defocus distance. Figure 3The red trapezoidal area representing the laser beam in Figure (b) is larger, indicating that the laser spot size is increased after adjusting the defocus distance. The change in the intersection of the red trapezoidal area representing the laser beam and the material removal area in the figure indicates that the laser beam energy in the material removal area is further optimized, that is, the beam energy distribution in the cutting area is further optimized, indicating that the method of this application can improve material cutting performance and enhance the quality of free-form surface processing.

[0042] Figure 3 Figure d in the middle is Figure 2 The corresponding diagram in Figure d (center) shows the change in the irradiated area after adjusting the laser emission position according to the actual offset. This shows that by adjusting the laser emission angle, the laser center and the tool cutting center are aligned (i.e., both are located at the positions indicated by the blue dashed lines). This further demonstrates that this method can optimize the beam energy distribution in the cutting area, thereby improving material cutting performance and enhancing the quality of freeform surface machining.

[0043] Example 2 This embodiment provides a device capable of implementing any of the above laser-assisted processing beam adaptive control methods, such as Figure 4 and 5 As shown, the device includes: a servo linear displacement unit 1, a servo angular displacement unit 2, a laser-assisted processing unit and an external control unit (not shown in the figure). The laser-assisted processing unit includes a laser 3. The external control unit is used to control the servo linear displacement unit 1 to drive the laser 3 to move linearly according to the defocus distance of the laser beam, and is also used to control the servo angular displacement unit 2 to drive the laser 3 to rotate according to the deflection angle of the laser beam, thereby realizing adaptive control of the processing beam.

[0044] Specifically, the device of the laser-assisted processing beam adaptive control method in this embodiment also includes a base plate 4, on which a focusing mirror 5, an optical window 6 and a diamond tool 7 are arranged in sequence along the propagation direction of the laser beam. The laser 3 is arranged on the side of the focusing mirror 5 away from the optical window 6. The servo linear displacement unit 1 is fixed on the base plate 4 and is located directly below the laser 3. The servo angular displacement unit 2 is arranged between the servo linear displacement unit 1 and the laser 3.

[0045] Specifically, the servo linear displacement unit 1 receives control signals from an external control unit and converts them into linear displacement signals, thereby controlling the linear movement of the laser 3, such as forward and backward translation. The bottom of the servo linear displacement unit 1 is fixed to the base plate 4 with screws, and its top is connected to the adapter plate 8 with screws.

[0046] The bottom of the servo angle displacement unit 2 is fixed to the adapter plate 8 by screws. The servo angle displacement unit 2 is used to receive the control electrical signal and convert the control electrical signal into an angle displacement signal to control the laser 3 to rotate.

[0047] The aforementioned laser-assisted processing unit is used to generate a laser beam with adjustable power, and accurately concentrate the laser beam on the tip of the diamond tool 7 and emit it for laser-assisted cutting. Specifically, the laser 3 is used to generate a laser beam with adjustable power, and the power range is not greater than 50W. The laser 3 is fixed between the laser support seat 9 and the laser cover 10 by screws. The laser support seat 9 is connected to the servo angle displacement unit 2 by screws, so that the laser 3 can move and rotate with the servo angle displacement unit 2.

[0048] The aforementioned focusing mirror 5 is used to focus the laser beam generated by the laser 3, focusing the millimeter-level laser beam into a micron-level laser beam, and is fixed between the focusing mirror support seat 11 and the focusing mirror cover 12 by screws. The focusing mirror support seat 11 is connected to the base plate 4 by screws.

[0049] The optical window 6 is used to shape the laser beam focused by the focusing lens 5, precisely concentrating it at the tip of the diamond tool 7 to heat and soften the workpiece material in the cutting area. The optical window 6 is fixed by screws between the optical window support 12 and the optical window cover 13. The optical window support 12 is also connected to the base plate 4 by screws.

[0050] The diamond tool 7 is used to contact the workpiece surface, remove softened material through end cutting motion, form chips, and shape the machined surface. The diamond tool 7 is fixed to the diamond tool holder 14 by screws, and the diamond tool holder 14 is connected to the base plate 4 by screws.

[0051] Example 3 This embodiment provides an apparatus for implementing any of the above methods for adaptively controlling a laser-assisted processing beam, including: The machining path planning module is used to plan the tool path on the free-form surface to be machined and calculate the surface derivative equation; specifically, it is used to analyze the various parameters and characteristics of the ideal machining surface, fully consider the machining process requirements, precision standards, material properties and other factors, design a suitable machining program according to the characteristics and performance of the machining equipment, and plan the optimal movement path of the tool during the machining process to ensure that the tool can cut the workpiece efficiently and accurately to achieve the ideal surface shape.

[0052] A laser beam deflection angle acquisition module is used to obtain the deviation between the actual position center of the contact area between the tool and the surface to be processed and the designed position center of the contact area between the tool and the surface to be processed using the tool geometric parameters and the surface derivative function equation; and is also used to calculate the laser beam deflection angle using the deviation value; A laser beam defocus distance acquisition module is used to obtain the laser spot size and laser power density distribution using the actual length of the contact area between the tool and the surface to be processed; and is also used to obtain the laser beam defocus distance using the laser spot size and laser power density distribution; The adaptive control module is used to control the rotation of the laser along the deflection angle of the laser beam; it is also used to control the linear movement of the laser along the defocus distance of the laser beam.

[0053] It should be noted that the apparatus of the laser-assisted machining beam adaptive control method provided in this embodiment and the laser-assisted machining beam adaptive control method described above can refer to each other, and will not be described in detail here.

[0054] It is understandable that the detailed functional implementation of each of the above units / modules can be found in the introduction of the aforementioned method embodiment, and will not be repeated here.

[0055] It should be understood that the above-mentioned device is used to execute the method in the above-mentioned embodiment. The implementation principle and technical effect of the corresponding program module in the device are similar to those described in the above-mentioned method. The working process of the device can refer to the corresponding process in the above-mentioned method and will not be repeated here.

[0056] The method steps in the embodiments of the present application can be implemented by hardware or by a processor executing software instructions. The software instructions can be composed of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, mobile hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and storage medium can be located in an ASIC.

[0057] The above embodiments can be implemented in whole or in part using software, hardware, firmware, or any combination thereof. When implemented using software, they can be implemented in whole or in part in the form of a computer program product. The computer program product comprises one or more computer instructions. When loaded and executed on a computer, the computer program instructions fully or partially produce the processes or functions described in the embodiments of this application. 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 a computer-readable storage medium or transmitted via the 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, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disk, hard disk, tape), optical media (e.g., DVD), or semiconductor media (e.g., solid-state drive (SSD)).

[0058] It will be understood that the various numerical numbers involved in the embodiments of the present application are merely distinctions for the convenience of description and are not intended to limit the scope of the embodiments of the present application.

[0059] It is easy for those skilled in the art to understand that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

[0060] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0061] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0062] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship after the connection remains unchanged. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection. The directional terms mentioned in the embodiments of the present application, such as "top", "bottom", "inside", "outside", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0063] In addition, in the embodiments of the present application, the mathematical concepts mentioned include symmetry, equality, parallelism, and perpendicularity. These limitations are all for the current state of the art, rather than being absolutely strict definitions in a mathematical sense. A small amount of deviation is allowed, and it is possible to be approximately symmetric, approximately equal, approximately parallel, or approximately perpendicular. For example, A and B are parallel, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. A and B are perpendicular, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0064] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A beam adaptive control method for laser-assisted processing of free-form surfaces, characterized in that: include: S1 plans the tool path on the free-form surface to be machined and calculates the surface derivative equation; S2 uses the tool geometric parameters and the surface derivative function equation to obtain the deviation between the actual position center of the contact area between the tool and the surface to be processed and the designed position center of the contact area between the tool and the surface to be processed; and uses the deviation to calculate the laser beam deflection angle; S3 obtains the laser spot size and laser power density distribution using the actual length of the contact area between the tool and the surface to be processed; and obtains the laser beam defocus distance using the laser spot size and laser power density distribution; S4 causes the laser to rotate along the laser beam deflection angle and to move linearly along the laser beam defocus distance, so as to achieve adaptive control of the laser beam.

2. The laser-assisted processing beam adaptive control method according to claim 1, characterized in that: In step S1, the surface derivative function equation is expressed as: z'=g1(x,y) Among them, z is the surface sag, and g1(x,y) represents the functional relationship between the surface sag z and the surface coordinates (x,y).

3. The laser-assisted processing beam adaptive control method according to claim 1, characterized in that: In step S2, the actual position center of the contact area between the tool and the surface to be machined is expressed as: X1=m1(x,y) Among them, X1 is the coordinate of the actual position center along the x direction, and m1 is the functional relationship between the coordinate X of the actual position center and the coordinate (x, y) of the surface processing point; The design position center coordinates of the contact area between the tool and the surface to be machined are expressed as: X2=n1(x,y) Among them, X2 is the coordinate of the design position center along the x direction, and n1 is the functional relationship between the design position center coordinate X and the coordinate (x, y) of the surface processing point; The deviation value is calculated using the following formula: X0=X1-X2 Wherein, X0 is the deviation value.

4. The laser-assisted processing beam adaptive control method according to claim 1, wherein: In step S2, the laser beam deflection angle is calculated using the following formula: θ=X0 / I Wherein, θ is the deflection angle of the laser beam, X0 is the deviation value, and I is the distance from the laser output end of the laser to the tip of the tool.

5. The laser-assisted processing beam adaptive control method according to claim 1, wherein: In step S3, the actual length of the contact area between the tool and the surface to be processed is first used to determine the spot radius of the laser beam, and then the Gaussian beam intensity distribution expression is used to calculate the optimal power density distribution of the laser beam corresponding to the spot radius. The Gaussian beam intensity distribution expression is: in, I 0 is the beam power density at the center of the Gaussian beam waist, ω ( z ) is the spot radius, ω 0 is the waist radius, z is the surface sag, r is the theoretical Gaussian beam radius, P 0 is the total power of the laser beam.

6. The laser-assisted processing beam adaptive control method according to claim 1, wherein: In step S3, the laser spot size and laser power density distribution are used to obtain the formula for the laser beam defocus distance: in, ω ( z ) is the spot radius, z0 is the laser beam defocus distance, z R is the Rayleigh range; The formula for calculating the Rayleigh range is: in, is the laser beam wavelength, M 2 is the quality factor of the laser beam, ω 0 is the beam waist radius.

7. A device for implementing the laser-assisted processing beam adaptive control method according to any one of claims 1 to 6, characterized in that: include: A servo linear displacement unit (1), a servo angular displacement unit (2), a laser-assisted processing unit and an external control unit, wherein the laser-assisted processing unit includes a laser (3), and the external control unit is used to control the servo linear displacement unit (1) to drive the laser (3) to move linearly according to the defocus distance of the laser beam, and is also used to control the servo angular displacement unit (2) to drive the laser (3) to rotate according to the deflection angle of the laser beam, thereby realizing adaptive control of the processing beam.

8. The device according to claim 7, wherein The invention also includes a base plate (4), on which a focusing mirror (5), an optical window (6) and a diamond tool (7) are arranged in sequence along the propagation direction of the laser beam. The laser (3) is arranged on a side of the focusing mirror (5) away from the optical window (6). The servo linear displacement unit (1) is fixed on the base plate (4) and is located directly below the laser (3). The servo angular displacement unit (2) is arranged between the servo linear displacement unit (1) and the laser (3).

9. A device for implementing the laser-assisted processing beam adaptive control method according to any one of claims 1 to 6, characterized in that: include: The machining path planning module is used to plan the tool path on the free-form surface to be machined and calculate the surface derivative function equation; a laser beam deflection angle acquisition module, configured to obtain, using tool geometric parameters and the surface derivative equation, a deviation between the actual position center of the contact area between the tool and the surface to be machined and the designed position center of the contact area between the tool and the surface to be machined; and further configured to calculate the laser beam deflection angle using the deviation; A laser beam defocus distance acquisition module is used to obtain the laser spot size and laser power density distribution using the actual length of the contact area between the tool and the surface to be processed; and is also used to obtain the laser beam defocus distance using the laser spot size and laser power density distribution; The adaptive control module is used to control the laser to rotate along the deflection angle of the laser beam; and is also used to control the laser to move linearly along the defocus distance of the laser beam.

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