Optical lens polishing method based on multi-magnetorheological polishing tool cooperation

Abstract

The present application relates to the technical field of optical processing, and particularly relates to an optical lens polishing method based on multi-magnetorheological polishing tool cooperation, which is realized by a multi-magnetorheological polishing tool cooperation processing device, discrete surface shape residual data is obtained in combination with a target surface shape function of an optical lens to be processed, a removal function database under different removal volume removal rates is established by adjusting processing parameters of magnetorheological polishing tools, cooperation processing tracks of each magnetorheological polishing tool are set, residence time and rotation speed of a turntable of each residence point are calculated according to a material convolution removal model, and cooperation processing of the optical lens is realized by matching removal functions. The present application calculates residence time and material removal amount of each magnetorheological polishing tool at each residence point, obtains a material removal rate, and realizes cooperation processing of the multi-magnetorheological polishing tool on a large-size optical lens by matching removal functions, so that the processing efficiency of the optical lens is significantly improved while ensuring the accuracy of the processed surface shape.

Description

Technical Field

[0001] This invention belongs to the field of optical processing technology, and in particular relates to an optical lens polishing method based on the synergy of multiple magnetorheological polishing tools. Background Technology

[0002] With the rapid iteration and development of modern optical technology, the demand for large-aperture, high-precision aspherical optical lenses continues to rise, and they have irreplaceable application value in cutting-edge optical fields such as space telescopes, extreme ultraviolet lithography, and high-energy laser systems. These lenses not only exhibit a trend towards larger apertures but also impose stringent requirements on surface accuracy, typically needing to achieve nanometer-level root mean square accuracy. This dual requirement of high precision and high processing efficiency presents a significant challenge to the optical processing and manufacturing industry.

[0003] Magnetorheological polishing (MRP) utilizes the properties of a controllable magnetic field to cause a magnetorheological fluid containing magnetic particles to undergo instantaneous flow changes in the polishing area, forming a flexible polishing ribbon with viscoplastic characteristics. Combined with a computer control system that regulates the relative motion trajectory between the processing tool and the workpiece, it achieves minute and deterministic material removal. This technology boasts significant advantages such as excellent removal function stability, weak edge effects, and low subsurface damage, making it highly suitable for high-precision shaping of complex optical components. However, in the actual polishing process of large-aperture optical lenses, MRP still suffers from low material removal efficiency and a lengthy overall component processing cycle, hindering its engineering-scale mass application.

[0004] Current magnetorheological polishing equipment and processes primarily employ a multi-round, sequential processing strategy using a single magnetorheological polishing tool, completing lens polishing operations region by region according to a pre-set processing path. For polishing large-diameter optical lenses, the material removal efficiency is low, resulting in an excessively long overall processing cycle and difficulty in improving processing efficiency. Currently, there is no research on the collaborative and synchronous processing of optical lenses using multiple magnetorheological polishing tools. Summary of the Invention

[0005] In view of this, the present invention aims to provide an optical lens polishing method based on the synergy of multiple magnetorheological polishing tools, so as to precisely control the dwell time, ensure that the relative positions of each magnetorheological polishing tool are within the safe processing range, and realize the synergistic polishing of large-size optical lenses by multiple magnetorheological polishing tools.

[0006] To achieve the above objectives, the technical solution created by this invention is implemented as follows: An optical lens polishing method based on the synergy of multiple magnetorheological polishing tools is disclosed. This method utilizes a multi-magnetorheological polishing tool synergistic processing device, which includes at least two robotic arms, at least two magnetorheological polishing tools, and a turntable. The magnetorheological polishing tools are mounted on the end effectors of the robotic arms. An optical lens to be processed is fixedly mounted on the turntable, used to rotate the optical lens around its center point. The method includes the following steps: S1: Obtain the target surface shape function of the optical lens Discretized surface data are used to obtain discretized surface residual data. ; S2: By adjusting the processing parameters of the magnetorheological polishing tool, the removal function of the magnetorheological polishing tool under different volume removal rates is obtained, and a removal function database is established based on the removal function and its corresponding processing parameters; S3: Set the collaborative machining trajectory for each magnetorheological polishing tool. ,in, , This indicates the part number of the magnetorheological polishing tool. , This represents the total number of magnetorheological polishing tools; j Indicates the number of the station. , Indicates the total number of outposts; S4: Calculate the dwell time at each stop point. Corresponding removal function and turntable speed This completes the coordinated matching of various magnetorheological polishing tools; S5: Based on the processing trajectory Duration of stay and removal function Generate motion / posture control files for the robotic arm and turntable speed control files, as well as parameter control files for the magnetorheological polishing tools, to complete collaborative processing using multiple magnetorheological polishing tools.

[0007] Furthermore, in step S2, the processing parameters include the polishing gap, the magnetorheological fluid flow rate, and the polishing wheel rotation speed.

[0008] Furthermore, in step S2, the difference in the outer contour of the removal function of the same magnetorheological polishing tool under different volume removal rates is less than a preset difference.

[0009] Furthermore, based on the collaborative machining trajectory in step S3, the normal direction of each magnetorheological polishing tool at each dwell point is calculated. This is used to adjust the posture of each magnetorheological polishing tool in real time during the processing; in the first... j Normal direction at each station The calculation method is as follows: ; ; ; in, In the first j The target surface shape function of the optical lens at each dwell point.

[0010] Furthermore, step S4 includes the following steps: S41: Select the removal function corresponding to the minimum volumetric removal rate for each magnetorheological polishing tool from the removal function database as the benchmark removal function. ; S42: Based on the baseline removal function Processing trajectory and surface residual data The material convolution removal model was used to calculate the dwell points of each magnetorheological polishing tool on the machining trajectory. Duration of stay The formula for the material convolution removal model is: ; in, This represents a two-dimensional convolution operation. Indicates in Location-specific surface residual data, Indicates the first n A magnetorheological polishing tool in Duration of stay at the location; S43: Based on length of stay Calculate the amount of material removed by the magnetorheological polishing tool at each dwell point. The calculation formula is: ; S44: Select As a baseline dwell time, that is, setting the dwell time of each magnetorheological polishing tool at each corresponding dwell point as 1. To ensure the amount of material removed Volume removal rate at each retention point for: ; And calculate the turntable speed. : ; in, L The distance between adjacent rest stops. The horizontal distance from the dwell point to the center of the optical lens represents the dwell point of each magnetorheological polishing tool that is processing simultaneously. Same, satisfy ; S45: Using the baseline removal function and benchmark dwell time Simulation processing is performed using a simulation program to obtain the surface residual of the optical lens after simulated processing. If the root mean square of the surface residual is not greater than the preset threshold, the current dwell time, removal function and turntable speed are output; if the root mean square of the surface residual is greater than the preset threshold, the removal function is rematched according to the removal function database, and steps S42 to S45 are repeated until the threshold condition is met.

[0011] Furthermore, step S5 includes the following steps: Step S51: Combine machining trajectory Duration of stay Normal direction and turntable speed Generate motion / posture control files for the robotic arm and turntable speed control files, enabling the robotic arm to control the magnetorheological polishing tool to work in conjunction with the turntable to achieve collaborative processing along a preset processing trajectory; Step S52: Obtain the removal function from the removal function database. The corresponding processing parameters are used to generate a parameter control file for the magnetorheological polishing tool; Step S53: Establish a real-time communication network between multiple robotic arms, multiple magnetorheological polishing tools, and the turntable. During the processing, synchronously control the turntable speed, the movement and posture of the multiple robotic arms, and the processing parameters of the multiple magnetorheological polishing tools to achieve collaborative processing of optical lenses in time and space.

[0012] Compared with the prior art, the present invention can achieve the following beneficial effects: This invention plans a collaborative processing path for multiple magnetorheological polishing tools, calculates the material removal amount of each tool at each dwell point, and adjusts the processing parameters of each tool to change its removal function and material removal rate, thereby controlling the dwell time at each dwell point. This ensures that the relative positions of each tool are within a safe processing range, enabling collaborative polishing of large-size optical lenses using multiple magnetorheological polishing tools. This significantly improves the processing efficiency of optical lenses while maintaining the accuracy of the processed surface. Attached Figure Description

[0013] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic flowchart of the optical lens polishing method based on the synergy of multiple magnetorheological polishing tools, as described in an embodiment of the present invention. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0015] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0016] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

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

[0018] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] like Figure 1As shown, this embodiment of the invention provides an optical lens polishing method based on the synergy of multiple magnetorheological polishing tools. This method utilizes a multi-magnetorheological polishing tool synergistic processing device, which includes at least two robotic arms, at least two magnetorheological polishing tools, and a turntable. The magnetorheological polishing tools are mounted on the end effectors of the robotic arms, and the optical lens to be processed is fixedly mounted on the turntable, used to drive the optical lens to rotate around its center point. The optical lens polishing method includes the following steps: S1: Obtain the target surface shape function of the optical lens Discretized surface data are used to obtain discretized surface residual data. .

[0020] Based on the surface shape characteristics of the optical lens, obtain its target surface shape function. Discrete surface shape data of optical lenses are obtained through measuring equipment such as interferometers. ,in, , , For the first optical lens i The three-dimensional spatial coordinates of a discrete surface point This represents the total number of discrete surface points of the optical element.

[0021] By combining the target surface shape function and discretized surface shape data of the optical lens, the discretized surface shape residual data of the optical lens are obtained. ,in, , Discrete points on the optical lens The difference in elevation between the point and the target surface is the amount of material to be removed.

[0022] S2: By adjusting the processing parameters of the magnetorheological polishing tool, the removal function of the magnetorheological polishing tool under different volume removal rates is obtained, and a removal function database is established based on the removal function and its corresponding processing parameters.

[0023] By adjusting the processing parameters of the magnetorheological polishing tool, single-point polishing was performed on experimental lenses of the same material as optical lenses using this tool, and the volume removal rate of the magnetorheological polishing tool at different volumes was obtained. The system uses removal functions and their corresponding processing parameters to create a removal function database. This database will be used for matching removal functions in subsequent processing steps.

[0024] It should be noted that the difference in the outer contour of the removal function of the same magnetorheological polishing tool at different volume removal rates is less than a preset difference. This ensures that when the material removal amount distribution per unit time changes proportionally, the outer contour of the removal function remains unchanged or its difference is less than the preset difference. This allows for the same total material removal amount to be obtained at the same dwell point by adjusting the processing parameters of the magnetorheological polishing tool at different dwell times. This avoids the problem of excessive material removal in non-target processing areas around the dwell point due to an increase in the outer contour of the removal function, thus ensuring polishing removal accuracy.

[0025] In some embodiments, processing parameters Including polishing gaps Magnetorheological fluid flow rate and polishing wheel speed wait.

[0026] S3: Set the collaborative machining trajectory for each magnetorheological polishing tool. ,in, , This indicates the part number of the magnetorheological polishing tool. , This represents the total number of magnetorheological polishing tools; j Indicates the number of the station. , J This indicates the total number of outposts.

[0027] Setting the collaborative machining trajectory of each magnetorheological polishing tool ,in, , This indicates the part number of the magnetorheological polishing tool. , This represents the total number of magnetorheological polishing tools; j Indicates the station number, , Indicates the total number of dwell points; the collaborative machining trajectory of each magnetorheological polishing tool. The dwell points correspond one-to-one, and the total number of dwell points for each magnetorheological polishing tool in the collaborative processing area on the optical lens is the same. and corresponding depot Horizontal distance from the center of the optical lens It satisfies the following formula: ; This ensures that all magnetorheological polishing tools are positioned at the same radial direction during collaborative processing. Simultaneously, the normal direction at each dwell point is calculated. In the j Normal direction at each station The calculation method is as follows: ; ; ; in, In the first j The target surface shape function of the optical lens at each dwell point.

[0028] Normal direction Used to adjust the posture of the magnetorheological polishing tool in real time during the processing, ensuring that the magnetorheological fluid on the magnetorheological polishing tool always maintains optimal contact with the surface shape of the optical lens.

[0029] S4: Calculate the dwell time at each stop point. Corresponding removal function and turntable speed Step S4 includes the following steps: S41: Select the removal function corresponding to the minimum volumetric removal rate for each magnetorheological polishing tool from the removal function database as the benchmark removal function. ; S42: Based on the baseline removal function Processing trajectory and surface residual data The material convolution removal model was used to calculate the dwell points of each magnetorheological polishing tool on the machining trajectory. Duration of stay The formula for the material convolution removal model is: ; in, This represents a two-dimensional convolution operation. Indicates in Location-specific surface residual data, Indicates the first n A magnetorheological polishing tool in Duration of stay at the location; S43: Based on length of stay Calculate the amount of material removed by the magnetorheological polishing tool at each dwell point. The calculation formula is: ; S44: Select As a baseline dwell time, that is, setting the dwell time of each magnetorheological polishing tool at each corresponding dwell point as 1. To ensure the amount of material removed Volume removal rate at each retention point for: ; And calculate the turntable speed. : ; in, L The distance between adjacent rest stops. The horizontal distance from the dwell point to the center of the optical lens represents the dwell point of each magnetorheological polishing tool that is processing simultaneously. Same, satisfy ; In some embodiments, the turntable speed can also be preset. Then, calculate the base residence time at the corresponding residence point. .

[0030] S45: Using the baseline removal function and benchmark dwell time The surface residual was obtained by simulating the machining process using MATLAB simulation program. : ; Determine whether the surface residual after simulation processing meets the threshold condition: If the surface residual If the root mean square (RMS) is not greater than a preset threshold, a match is successful, and the current dwell time is output. Removal function and turntable speed ; If the RMS value is greater than the preset threshold, the match fails, and a new removal function is matched based on the removal function database. Using this as the baseline removal function, repeat steps S42 to S45 until the threshold condition is met.

[0031] S5: Based on the processing trajectory Duration of stay and removal function Generate motion / attitude control files for the robotic arm and turntable speed control files, as well as parameter control files for the magnetorheological polishing tools, to complete the collaborative processing of multiple magnetorheological polishing tools. Step S5 includes the following steps: Step S51: Combine machining trajectory Duration of stay Normal direction and turntable speed This generates motion / posture control files for the robotic arm and turntable speed control files, enabling the robotic arm to control the magnetorheological polishing tool to work in conjunction with the turntable to achieve collaborative processing along a preset processing trajectory.

[0032] Step S52: Obtain the removal function from the removal function database. The corresponding processing parameters are used to generate the parameter control file for the magnetorheological polishing tool.

[0033] Step S53: Establish a real-time communication network between multiple robotic arms, magnetorheological polishing tools, and a turntable. During the processing, synchronously control the movement and posture of the multiple robotic arms and the processing parameters of the multiple magnetorheological polishing tools to achieve collaborative processing of optical lenses in time and space by multiple magnetorheological polishing tools.

[0034] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0035] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for polishing optical lenses based on the synergy of multiple magnetorheological polishing tools, implemented using a multi-magnetorheological polishing tool synergistic processing device, the device comprising at least two robotic arms, at least two magnetorheological polishing tools, and a turntable; the magnetorheological polishing tools are mounted on the end effectors of the robotic arms, and an optical lens to be processed is fixedly mounted on the turntable for rotating the optical lens around its center point; characterized in that... Includes the following steps: S1: Obtain the target surface shape function of the optical lens. Discretized surface data are used to obtain discretized surface residual data. ; S2: By adjusting the processing parameters of the magnetorheological polishing tool, the removal function of the magnetorheological polishing tool under different volume removal rates is obtained, and a removal function database is established based on the removal function and its corresponding processing parameters; S3: Set the collaborative machining trajectory for each magnetorheological polishing tool. ,in, , This indicates the part number of the magnetorheological polishing tool. , This represents the total number of magnetorheological polishing tools; j Indicates the number of the station. , Indicates the total number of outposts; S4: Calculate the dwell time at each stop point. Corresponding removal function and turntable speed This completes the coordinated matching of various magnetorheological polishing tools; Step S4 includes the following steps: S41: Select the removal function corresponding to the minimum volumetric removal rate for each magnetorheological polishing tool from the removal function database as the benchmark removal function. ; S42: Based on the benchmark removal function Processing trajectory and surface residual data The material convolution removal model was used to calculate the dwell points of each magnetorheological polishing tool on the machining trajectory. Duration of stay The formula for the material convolution removal model is: ； in, This represents a two-dimensional convolution operation. Indicates in Location-specific surface residual data, Indicates the first n A magnetorheological polishing tool in Duration of stay at the location; S43: Based on the stated stay time Calculate the amount of material removed by the magnetorheological polishing tool at each dwell point. The calculation formula is: ； S44: Select As a baseline dwell time, that is, setting the dwell time of each magnetorheological polishing tool at each corresponding dwell point as 1. To ensure the amount of material removed Volume removal rate at each retention point for: ； And calculate the turntable speed. : ； in, L The distance between adjacent rest stops. The horizontal distance from the dwell point to the center of the optical lens, where the dwell points of each magnetorheological polishing tool being processed simultaneously are located. Same, satisfy ; S45: Using the aforementioned benchmark removal function and the benchmark dwell time The optical lens is simulated and processed using a simulation program to obtain the surface shape residual after the simulated processing. If the root mean square of the surface residual is not greater than a preset threshold, the current dwell time, removal function and turntable speed are output; if the root mean square of the surface residual is greater than the preset threshold, the removal function is rematched according to the removal function database, and steps S42 to S45 are repeated until the threshold condition is met. S5: Based on the processing trajectory Duration of stay and removal function Generate motion / posture control files for the robotic arm and turntable speed control files for the magnetorheological polishing tools, and complete the collaborative processing of multiple magnetorheological polishing tools; Step S5 includes the following steps: Step S51: Combine machining trajectory Duration of stay Normal direction and turntable speed Generate motion / posture control files for the robotic arm and turntable speed control files, enabling the robotic arm to control the magnetorheological polishing tool to work in conjunction with the turntable to achieve collaborative processing along a preset processing trajectory; Step S52: Obtain the removal function from the removal function database. The corresponding processing parameters are used to generate a parameter control file for the magnetorheological polishing tool; Step S53: Establish a real-time communication network between multiple robotic arms, multiple magnetorheological polishing tools, and the turntable. During the processing, synchronously control the turntable speed, the movement and posture of the multiple robotic arms, and the processing parameters of the multiple magnetorheological polishing tools to achieve the collaborative processing of the optical lens by the multiple magnetorheological polishing tools in time and space.

2. The optical lens polishing method based on the synergy of multiple magnetorheological polishing tools according to claim 1, characterized in that, In step S2, the processing parameters include polishing gap, magnetorheological fluid flow rate, and polishing wheel rotation speed.

3. The optical lens polishing method based on the synergy of multiple magnetorheological polishing tools according to claim 1, characterized in that, In step S2, the difference in the outer contour of the removal function of the same magnetorheological polishing tool under different volume removal rates is less than a preset difference.

4. The optical lens polishing method based on the synergy of multiple magnetorheological polishing tools according to claim 1, characterized in that, Based on the collaborative machining trajectory described in step S3, calculate the normal direction of the magnetorheological polishing tool at each dwell point. It is used to adjust the posture of each magnetorheological polishing tool in real time during the processing. In the j Normal direction at each station The calculation method is as follows: ； ； ； in, In the first j The target surface shape function of the optical lens at each dwelling point.

Images