Magneto-rheological removal function change measuring device and method based on shunt design

Abstract

The invention relates to the technical field of optical processing, in particular to a shunt design magnetorheological removal function change measuring device and method, and the device comprises a processing magnetorheological polishing system, a testing magnetorheological polishing system, a supply system and a control system; a robot and machining magneto-rheological polishing equipment in the machining magneto-rheological polishing system machine the optical element, and the machining magneto-rheological polishing equipment measures the flowing condition of magneto-rheological fluid in the machining process in real time. Testing magnetorheological polishing equipment in the testing magnetorheological polishing system is used for machining the optical element, and the flowing condition of magnetorheological fluid in the testing magnetorheological polishing system in the machining process is measured in real time; the supply system provides magnetorheological fluid for the machining magnetorheological polishing equipment and the testing magnetorheological polishing equipment at the same time. In the method, if the processing magnetorheological polishing system is blocked by magnetorheological fluid, the processing magnetorheological polishing system can be replaced by a pipeline in the testing magnetorheological polishing system, so that the consistency of processing parameters and quick restart of a processing state after pause due to the blockage of the pipeline are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical processing, and particularly relates to a device and method for measuring the change of magnetorheological removal function with a shunt design. Background Art

[0002] Magnetorheological Finishing (MRF) is an advanced optical manufacturing technology developed in recent years. It has many advantages such as a stable removal function, controllable edge effect, small subsurface damage layer, no copying effect, strong shaping ability, and high processing accuracy. Therefore, the magnetorheological finishing technology has received extensive attention in high-precision optical processing.

[0003] The prerequisite for the magnetorheological finishing technology to achieve high-precision processing depends on the stability of the removal function, that is, the removal function is stable during the processing or the change of the removal function during the processing is known. The stability of the removal function is closely related to the performance of the magnetorheological fluid. During the long-term processing, the performance of the magnetorheological fluid will gradually change. For example, the moisture in the magnetorheological fluid will volatilize and remain on the mirror surface, resulting in a change in its proportion. Therefore, it is inevitable that the removal function changes during the long-term processing. This requires measuring some parameters during the processing to reflect the change of the removal function. For example, measuring the liquid viscosity through a pressure sensor and measuring the liquid flow through a flow meter, etc. However, these parameters indirectly reflect the change of the removal function. There are also some parameters related to the change of the removal function that cannot or are inconvenient to measure during the processing, such as the iron powder concentration, polishing powder concentration, and particle sizes of the polishing powder and iron powder. It is difficult to truly and comprehensively clarify the change of the removal function solely relying on the existing measured parameters.

[0004] However, it is impossible or inconvenient to measure the actual change of the removal function on the optical element during the processing. The reason is that the processing range of the processing equipment is limited, and the spatial size of the optical element to be processed occupies most of the processing interval. Especially for the processing of large-aperture or even ultra-large-aperture optical elements, there is not enough space in the limited processing range to place another optical element for measuring the change of the removal function. When there is enough space in the processing area to place the test optical element and measure the removal function during the processing, it is necessary for the processing equipment to break away from the current processing state and process the test optical element with a new processing parameter, and then return to the processing state. However, due to the break of the current processing state, the continuity of the processing is interrupted. Even if the control program is used to control the processing equipment to return to the processing state at the interruption, due to the limitations of the motion performance of the processing equipment, it is impossible to be the same as the processing state before the interruption. Eventually, special processing marks will be generated on the surface of the optical element after processing, and these processing marks are very difficult to remove during the subsequent processing, ultimately affecting the processing accuracy. Summary of the Invention

[0005] In view of this, the present invention aims to provide a shunt-designed magnetorheological removal function change measurement device and method. In the device, more processing parameters can be measured to reflect the change of the removal function and the actual change of the removal function during processing can be obtained without breaking the actual processing state and interrupting the processing continuity. When the magnetorheological fluid in the magnetorheological polishing system is blocked, the pipeline in the test magnetorheological polishing system can be used to replace it, so as to achieve the consistency of processing parameters and the rapid restart of the processing state after suspension due to pipeline blockage.

[0006] To achieve the above object, the technical solution of the present invention is realized as follows: A shunt-designed magnetorheological removal function change measurement device includes a processing magnetorheological polishing system, a test magnetorheological polishing system, a supply system and a control system; wherein: the processing magnetorheological polishing system includes a robot and a processing magnetorheological polishing device arranged at the free end of the robot. The control system controls the robot and the processing magnetorheological polishing device to process the optical element. The processing magnetorheological polishing device measures the flow condition of the magnetorheological fluid inside the processing magnetorheological polishing device in real time during processing and transmits the measurement result to the control system; the test magnetorheological polishing system includes a position adjustment table and a test magnetorheological polishing device; the optical element is placed on the position adjustment table. The control system controls the position adjustment table to adjust the processing position of the optical element; the control system controls the test magnetorheological polishing device to cooperate with the position adjustment table to process the optical element and measures the flow condition of the magnetorheological fluid inside the test magnetorheological polishing device in real time during processing and transmits the measurement result to the control system; the supply system is controlled by the control system and supplies magnetorheological fluid to the processing magnetorheological polishing device and the test magnetorheological polishing device at the same time.

[0007] Further, the processing magnetorheological polishing device and / or the test magnetorheological polishing device includes: a magnetorheological polishing assembly for processing the optical element; a magnetorheological fluid flow measurement assembly for measuring the flow condition of the magnetorheological fluid in real time during processing; a stop valve controlled by the control system to control the flow and transportation of the magnetorheological fluid.

[0008] Further, the magnetorheological polishing assembly includes: a polishing wheel in contact with the optical element and cooperating with the magnetorheological fluid to process the optical element; a polishing motor controlled by the control system to drive the polishing motor; a nozzle connected to the supply system and supplying magnetorheological fluid to the polishing wheel; a magnet module for changing the stiffness of the magnetorheological fluid at the polishing wheel.

[0009] Further, the magnetorheological fluid flow measurement assembly includes: a pressure sensor that measures the pressure generated during the flow of the magnetorheological fluid and transmits the measured pressure to the control system; an electromagnetic flowmeter that measures the flow rate of the magnetorheological fluid and transmits the measured flow rate to the control system.

[0010] Further, the magnetorheological polishing system for processing and / or the magnetorheological polishing system for testing further includes: a force sensor that measures in real time the change in the force between the magnetorheological fluid and the optical element and transmits the measured force to the control system; a line laser measuring instrument that measures in real time the change in the ribbon thickness of the magnetorheological fluid and transmits the measured ribbon thickness to the control system.

[0011] Further, the magnetorheological polishing system for testing further includes a particle size measurement and medium content detection device; the particle size measurement and medium content detection device measures in real time the particle sizes of the iron powder and polishing powder in the magnetorheological fluid, as well as the contents of the iron powder, polishing powder, and moisture, and transmits the measured information to the control system.

[0012] Further, the supply system includes: a liquid storage module that stores and stirs the magnetorheological fluid; a recovery module that is controlled by the control system, recovers the magnetorheological fluid under the control of the control system, and transports the recovered magnetorheological fluid to the liquid storage module; a supply module that is controlled by the control system and transports the magnetorheological fluid in the liquid storage module to the magnetorheological polishing equipment for processing and / or the magnetorheological polishing equipment for testing.

[0013] A method for measuring the change in the magnetorheological removal function with a shunt design, according to the magnetorheological removal function change measurement device with a shunt design provided by the present invention, includes: S1: Control the supply system to transport the magnetorheological fluid to the magnetorheological polishing system for processing and the magnetorheological polishing system for testing, and control the magnetorheological polishing system for processing and the magnetorheological polishing system for testing to process the optical element to be processed and the test optical element respectively; S2: Monitor in real time the change in the magnetorheological fluid in the magnetorheological polishing system for processing, and determine whether there is a blockage of the magnetorheological fluid in the magnetorheological polishing system for processing; if a blockage occurs, execute step S3, otherwise repeat step S2 until the processing of the optical element to be processed is completed; S3: Exchange the pipelines corresponding to the blockage in the magnetorheological polishing system for processing and the magnetorheological polishing system for testing; restart the magnetorheological polishing system for processing to process the optical element to be processed; install the cleaned pipeline into the magnetorheological polishing system for testing; restart the magnetorheological polishing system for testing to process the test optical element; return to step S2.

[0014] Further, in step S2, determine the allowable pressure range of the magnetorheological fluid in the magnetorheological polishing system; in the magnetorheological polishing system, if the current pressure of the magnetorheological fluid does not exceed the allowable pressure range, it is determined that there is no blockage of the magnetorheological fluid, and step S2 is repeated; if the current pressure of the magnetorheological fluid exceeds the allowable pressure range, it is determined that there is a blockage of the magnetorheological fluid, and step S3 is executed.

[0015] Further, step S2 further includes: During the current data acquisition time, monitor the processing information of the test optical element by the test magnetorheological polishing system and the information on the composition of the magnetorheological fluid in the test magnetorheological polishing system; Determine the removal function information of the optical element to be processed according to the current processing information; Determine the next data acquisition time for the removal function information and the information on the composition of the magnetorheological fluid according to the current removal function information and the information on the composition of the magnetorheological fluid.

[0016] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) In the device and method for measuring the change of the magnetorheological removal function with shunt design according to the present invention, more processing parameters can be measured to reflect the change of the removal function and the actual change of the removal function during processing can be obtained without breaking the actual processing state and interrupting the continuity of processing. In addition, when there is a blockage of the magnetorheological fluid in the magnetorheological polishing system, the pipeline in the test magnetorheological polishing system can be used to replace it, so as to achieve the consistency of processing parameters and the rapid restart of the processing state after being suspended due to pipeline blockage; (2) In the method for measuring the change of the magnetorheological removal function with shunt design according to the present invention, by continuously measuring the parameters of the magnetorheological fluid and the change information of the removal function in the test magnetorheological polishing system, data support is provided for judging the surface shape error distribution during the subsequent processing of the optical element to be processed, data support is provided for the change of the virtual processing removal function of the subsequent optical element to be processed, and guidance on the selection of processing parameters and processing strategies is provided for further long-term processing. Description of the Drawings

[0017] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 is a schematic structural diagram of the device for measuring the change of the magnetorheological removal function with shunt design according to the embodiment of the present invention from one perspective; Figure 2 is a schematic structural diagram of the device for measuring the change of the magnetorheological removal function with shunt design according to the embodiment of the present invention from another perspective; Figure 3 Schematic flowchart of the shunt design method for measuring the change of magnetorheological removal function according to the embodiments of the present invention

[0018] Explanation of reference numerals: 1. Control system; 2. Robot; 3. Optical element; 4. Position adjustment table; 5. Test bench; 6. Independent support frame; 7. Polishing wheel; 8. Polishing motor; 9. Nozzle; 10. Magnet module; 11. Magnetorheological support frame; 12. Recycling box; 13. Pressure sensor; 14. Electromagnetic flowmeter; 15. Liquid storage module; 16. Recycling module; 17. Supply module; 18. Force sensor; 19. Line laser measuring instrument. Specific embodiments

[0019] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0020] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0021] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, 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 should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0022] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0024] As Figures 1 to 2 shown, the shunt design magnetic rheological removal function change measurement device according to the embodiment of the present invention includes a processing magnetic rheological polishing system, a testing magnetic rheological polishing system, a supply system, and a control system 1. Among them, the processing magnetic rheological polishing system includes a robot 2 and a processing magnetic rheological polishing device provided at the free end of the robot 2. The control system 1 controls the robot 2 and the processing magnetic rheological polishing device to process the optical element 3. The processing magnetic rheological polishing device measures in real time the flow condition of the magnetic rheological fluid inside the processing magnetic rheological polishing device during the processing and transmits the measurement result to the control system 1. The testing magnetic rheological polishing system includes a testing magnetic rheological polishing device and a position adjustment table 4. The optical element 3 is placed on the position adjustment table 4. The control system 1 controls the position adjustment table 4 to adjust the processing position of the optical element 3. The control system 1 controls the testing magnetic rheological polishing device to cooperate with the position adjustment table 4 to process the optical element 3 and measures in real time the flow condition of the magnetic rheological fluid inside the testing magnetic rheological polishing device during the processing and transmits the measurement result to the control system 1. The supply system is controlled by the control system 1 and supplies magnetic rheological fluid to the processing magnetic rheological polishing device and the testing magnetic rheological polishing device simultaneously.

[0025] In some embodiments, the processing magnetic rheological polishing device and / or the testing magnetic rheological polishing device includes a magnetic rheological polishing assembly, a magnetic rheological fluid flow measurement assembly, and a flow stop valve. The magnetic rheological polishing assembly processes the optical element 3. The magnetic rheological fluid flow measurement assembly measures in real time the flow condition of the magnetic rheological fluid during the processing. The flow stop valve is controlled by the control system 1 to block the flow and transportation of the magnetic rheological fluid.

[0026] In a certain embodiment, the structures of the processing magnetic rheological polishing device and the testing magnetic rheological polishing device are the same. The processing magnetic rheological polishing device is rigidly connected to the free end of the robot 2, so that the robot 2 drives the processing magnetic rheological polishing device to approach the optical element 3 placed on the experimental table 5 and processes the optical element 3. The testing magnetic rheological polishing device is placed near the experimental table 5 by an independent support frame 6. The position adjustment table 4 is placed in the independent support frame 6, so that the testing magnetic rheological polishing device cooperates with the position adjustment table 4 to process the optical element 3 placed on the position adjustment table 4. At the same time, the position adjustment table 4 preferably adopts a three-dimensional adjustment table to realize the three-dimensional movement of the position adjustment table 4 driving the optical element 3 in the front-back, left-right, and up-down directions to adjust the position of the optical element 3. In addition, the supply system supplies magnetic rheological fluid to the processing magnetic rheological polishing device and the testing magnetic rheological polishing device simultaneously through pipelines, so as to realize that the flow stop valve is controlled by the control system 1 to control the flow and transportation of the magnetic rheological fluid.

[0027] In some embodiments, the magnetorheological polishing assembly includes a polishing wheel 7, a polishing motor 8, a nozzle 9, and a magnet module 10. Among them, the polishing wheel 7 contacts the optical element 3 and cooperates with the magnetorheological fluid to process the optical element 3. The polishing motor 8 is controlled by the control system 1 to drive the polishing wheel 7. The nozzle 9 is connected to the supply system and supplies the magnetorheological fluid to the polishing wheel 7. The magnet module 10 changes the stiffness of the magnetorheological fluid at the polishing wheel 7.

[0028] In a certain embodiment, the polishing wheel 7, the polishing motor 8, the nozzle 9, and the magnet module 10 are installed on the magnetorheological support frame 11. In the processing magnetorheological polishing equipment, the magnetorheological support frame 11 is rigidly connected to the free end of the robot 2. In the test magnetorheological polishing equipment, the magnetorheological support frame 11 is rigidly connected to the independent support frame 6. The output end of the polishing motor 8 is connected to the rotating shaft of the polishing wheel 7 through a transmission belt, so that the control system 1 drives the polishing wheel 7 to process the optical element 3 through the polishing motor 8 and adjusts the rotation speed of the polishing wheel 7 during the processing. The nozzle 9 is installed on the magnetorheological support frame 11 along the rotation direction of the polishing wheel 7, so that the nozzle 9 supplies the magnetorheological fluid to the working point of the polishing wheel 7. The magnet module 10 is close to the working point of the polishing wheel 7. The magnetic induction intensity of the magnet module 10 changes the stiffness of the magnetorheological fluid at the working point of the polishing wheel 7, thereby realizing the processing of the optical element 3 by the polishing wheel 7 in cooperation with the magnetorheological fluid. It should be noted that the working point of the polishing wheel 7 is the point on the polishing wheel 7 where the distance from the optical element 3 is the smallest when the polishing wheel 7 contacts the optical element 3. In addition, a recovery box 12 for recovering the magnetorheological fluid is installed near the polishing wheel 7. The polishing wheel 7 sends the remaining magnetorheological fluid after processing into the recovery box 12. The recovery box 12 is connected to the supply system through a pipeline to ensure that the recovered magnetorheological fluid can return to the supply system, realizing the recycling of the magnetorheological fluid. It should be noted that the installation position of the recovery box 12 shall not interfere with the normal processing of the polishing wheel 7. The magnet module 10 can be an independent electromagnet that changes the magnetic induction intensity by current, voltage, etc., or an independent magnet with a constant magnetic induction intensity, or a combination of an electromagnet and a magnet, or other forms of magnets that can generate magnetic induction intensity. The present invention does not limit the form and composition of the magnet module 10.

[0029] In some embodiments, the magnetorheological fluid flow measurement assembly includes a pressure sensor 13 and an electromagnetic flowmeter 14. Among them, the pressure sensor 13 measures the pressure generated during the flow of the magnetorheological fluid and transmits the measured pressure to the control system 1. The electromagnetic flowmeter 14 measures the flow rate of the magnetorheological fluid and transmits the measured flow rate to the control system 1.

[0030] In one embodiment, the pressure sensor 13 and the electromagnetic flowmeter 14 are connected to the pipeline for transporting the magnetorheological fluid. The pressure sensor 13 measures the pressure of the magnetorheological fluid in the pipeline, and the electromagnetic flowmeter 14 measures the flow rate of the magnetorheological fluid in the pipeline.

[0031] In some embodiments, the supply system includes a liquid storage module 15, a recycling module 16, and a supply module 17. Among them, the liquid storage module 15 stores and stirs the magnetorheological fluid; the recycling module 16 is controlled by the control system 1 to recycle the magnetorheological fluid and transport the recycled magnetorheological fluid to the liquid storage module 15; the supply module 17 is controlled by the control system 1 to transport the magnetorheological fluid in the liquid storage module 15 to the processing magnetorheological polishing equipment and / or the testing magnetorheological polishing equipment. In one embodiment, the control system 1 controls the recycling speed of the recycling module 16 and the supply speed of the supply module 17. The supply module 17 supplies the magnetorheological fluid in the liquid storage module to the nozzle 9 of the processing magnetorheological polishing equipment and the testing magnetorheological polishing equipment through a pipeline, and the magnetorheological fluid from the recycling box 12 enters the recycling module through a pipeline.

[0032] In one embodiment, to reduce the overall volume of the magnetorheological removal function change measurement device with a shunt design, in the processing magnetorheological polishing system, it is preferably to install the liquid storage module 15, the recycling module 16, and the supply module 17 on the robot 2. In the testing magnetorheological polishing system, it is preferably to install the liquid storage module 15, the recycling module 16, and the supply module 17 on the independent support frame 6.

[0033] In some embodiments, the processing magnetorheological polishing system and / or the testing magnetorheological polishing system further includes a force sensor 18 and a line laser measuring instrument 19. Among them, the force sensor 18 measures the change in the force between the magnetorheological fluid and the optical element 3 in real time, and the line laser measuring instrument 19 measures the change in the ribbon thickness of the magnetorheological fluid in real time.

[0034] In one embodiment, both the processing magnetorheological finishing system and the testing magnetorheological finishing system further include a force sensor 18 and a line laser measuring instrument 19. The force sensor 18 preferably uses a six-axis force sensor and is installed at the magnetorheological support frame 11. By sensing the movement change of the magnetorheological support frame 11, the change in the force between the magnetorheological fluid and the optical element 3 when passing through the working area is obtained. In the processing magnetorheological finishing system, the force sensor 18 is installed at the connection between the free end of the robot 2 and the magnetorheological support frame 11. In the testing magnetorheological finishing system, the force sensor 18 is installed at the connection between the independent support frame 6 and the magnetorheological support frame 11. The line laser measuring instrument 19 is mounted on the magnetorheological support frame 11, and the detection position of the line laser measuring instrument 19 irradiates the working point of the polishing wheel 7 to measure the change in the ribbon thickness formed after the magnetorheological fluid passes through the polishing gap in real time. It should be noted that the polishing gap here is the distance between the working point of the polishing wheel 7 and the optical element 3, and the working area of the magnetorheological fluid is the area when the polishing wheel 7 processes the optical element 3.

[0035] In some embodiments, the testing magnetorheological finishing system further includes a particle size measurement and medium content detection device, which measures the particle sizes of iron powder and polishing powder in the magnetorheological fluid, as well as the contents of iron powder, polishing powder, and moisture in real time.

[0036] A method for measuring the change of the magnetorheological removal function with a shunt design, according to the magnetorheological removal function change measurement device with a shunt design described in the embodiments of the present invention, as Figures 1 to 3 shown, includes: S1: Control the supply system to deliver the magnetorheological fluid to the processing magnetorheological finishing system and the testing magnetorheological finishing system, and control the processing magnetorheological finishing system and the testing magnetorheological finishing system to process the optical element to be processed and the testing optical element respectively.

[0037] S2: Monitor the change of the magnetorheological fluid in the processing magnetorheological finishing system in real time, and judge whether there is a blockage of the magnetorheological fluid in the processing magnetorheological finishing system; if a blockage occurs, execute step S3, otherwise repeat step S2 until the processing of the optical element to be processed is completed.

[0038] In some embodiments, in step S2, determine the allowable pressure range of the magnetorheological fluid in the processing magnetorheological finishing system; in the processing magnetorheological finishing system, if the current pressure of the magnetorheological fluid does not exceed the allowable pressure range, it is determined that there is no blockage of the magnetorheological fluid, and step S2 is repeated; if the current pressure of the magnetorheological fluid exceeds the allowable pressure range, it is determined that there is a blockage of the magnetorheological fluid, and step S3 is executed.

[0039] Combined with the magnetic rheological removal function change measurement device with shunt design described in the embodiments of the present invention, it can be understood that a pressure sensor 13 is used to measure the pressure generated during the flow of the magnetic rheological fluid, and the allowable range of the pressure P of the magnetic rheological fluid in the processing magnetic rheological polishing system is determined as [P min , P max . If the current pressure P of the magnetic rheological fluid is not within the allowable pressure range [P min , P max , that is, P ∉ [P min , P max , it is determined that the magnetic rheological fluid is blocked, and step S3 is executed; otherwise, if the current pressure P of the magnetic rheological fluid is within the allowable pressure range [P min , P max , that is, P ∈ [P min , P max , it is determined that the magnetic rheological fluid is not blocked, and step S2 is repeated.

[0040] In an embodiment, the blockage position of the magnetic rheological fluid can be determined by the specific relationship between the current pressure P of the magnetic rheological fluid and the allowable pressure range [P min , P max . Specifically, if the current pressure P of the magnetic rheological fluid is less than the minimum value P min of the allowable pressure range, that is, P < P min , it is determined that the part of the pipeline before the pressure sensor is blocked; if the current pressure P of the magnetic rheological fluid is greater than the maximum value P max of the allowable pressure range, that is, P > P max , it is determined that the part of the pipeline after the pressure sensor is blocked.

[0041] In some embodiments, step S2 further includes: During the current data acquisition time, monitor the processing information of the test magnetic rheological polishing system on the test optical element and the composition information of the magnetic rheological fluid in the test magnetic rheological polishing system.

[0042] In an embodiment, combined with the magnetic rheological removal function change measurement device with shunt design described in the embodiments of the present invention, during the process of monitoring the processing information of the test magnetic rheological polishing system on the test optical element and the composition information of the magnetic rheological fluid in the test magnetic rheological polishing system at the current data acquisition time: The processing information includes: using the pressure sensor 13 to measure the pressure P' generated during the flow of the magnetic rheological fluid, and the corresponding allowable pressure range is [P' min , P' max , where P' min represents the minimum value of the preset pressure P', and P' maxRepresents the maximum value of the preset pressure P'; the flow rate Q of the magnetorheological fluid is measured by the electromagnetic flowmeter 14, and the corresponding flow rate allowable range is [Q min ,Q max ], Q min Indicates the minimum value of the preset flow rate Q, Q max Indicates the maximum value of the preset flow rate Q; the force sensor 18 is used to measure the change of the force F during processing, and the corresponding force allowable range is [F min ,F max ],F min Indicates the preset minimum value of the processing force F, F max Represents the maximum value of the preset processing force F; the change of the ribbon thickness H formed by the magnetorheological fluid after passing through the polishing gap is measured by a line laser measuring instrument 19, and the corresponding allowable range of the ribbon thickness is [H min ,H max ], H min Indicates the minimum value of the preset ribbon thickness H, H max Indicates the maximum value of the preset ribbon thickness H. All allowable ranges in the processing information, that is, the maximum and minimum values of each parameter in the processing information, need to be determined according to actual conditions; The composition information of the magnetorheological fluid includes: the particle size measurement and medium content detection device is used to measure the particle size D of the iron powder in the magnetorheological fluid. F , polishing powder particle size D C , iron powder content FC and water content MC. Particle size D of iron powder F The corresponding allowable range of iron powder particle size is [D Fmin ,D Fmax ], D Fmin Indicates the preset particle size D of the iron powder F The minimum value of D Fmax Indicates the preset particle size D of the iron powder F The maximum value of the polishing powder particle size D C The corresponding allowable range of polishing powder particle size is [D Cmin ,D Cmax ], D Cmin Indicates the preset polishing powder particle size D C The minimum value of D Cmax Indicates the preset polishing powder particle size D C The maximum value of the iron powder content FC corresponds to the allowable range of iron powder content [FC min ,FC max ], FC min Indicates the minimum value of the preset iron powder content FC, FC max Indicates the maximum value of the preset iron powder content FC; the moisture content MC corresponds to the allowable moisture content range of [MC min ,MCmax , MC min represents the minimum value of the preset moisture content MC, MC max represents the maximum value of the preset moisture content MC. All allowable ranges in the magnetorheological fluid composition information, that is, the maximum and minimum values of each parameter in the magnetorheological fluid composition information, are determined according to the actual situation.

[0043] Determine the removal function information of the optical element to be processed according to the current processing information.

[0044] In one embodiment, in the process of determining the removal function information of the optical element to be processed according to the current processing information: the removal function information includes the removal function volume removal rate MRR, and the corresponding allowable range of the removal rate is [MRR min , MRR max , MRR min represents the minimum removal function volume removal rate, MRR max represents the maximum removal function volume removal rate. Further explanation for the selection of the removal rate range according to the linear material removal theory: the surface shape residual ΔE = E - R0 T, where R0 represents the initially set removal function, E represents the initial surface shape error of the optical element, T represents the dwell time, and ΔE represents the surface shape residual, represents the convolution calculation. When the removal function R changes to the minimum value R of the removal function min or the maximum value R of the removal function max , and the corresponding removal function volume removal rate is MRR min or MRR max , the corresponding surface shape residual becomes the minimum surface shape residual ΔE min or the maximum surface shape residual ΔE max . Compare the RMS value of ΔE min or ΔE max with the RMS value of the processing target. If RMS(ΔE min ) or RMS(ΔE max ) is equal to the RMS value of the processing target, then the allowable range of the removal rate is determined to be [MRR min , MRR max .

[0045] Determine the data acquisition time for the next removal function information and magnetorheological fluid composition information according to the current removal function information and magnetorheological fluid composition information.

[0046] In one embodiment, in the process of determining the next data acquisition time for the removal function information and the magnetorheological fluid composition information in combination with the magnetorheological removal function change measurement device described in the embodiments of the present invention: If the measured pressure P', flow rate Q, force F, and ribbon thickness H are all within the corresponding allowable ranges, that is: P' ∈ [P' min , P' max , Q ∈ [Q min , Q max , F ∈ [F min , F max , and H ∈ [H min , H max , then start accumulating the time from the beginning of the processing. The next data acquisition time interval is ΔT1. The time interval ΔT1 is usually relatively long, generally several tens of hours. At the next data acquisition time interval ΔT1, use the test magnetorheological polishing equipment to perform fixed-point processing on the optical element to be tested for a period of time to obtain the true volume removal rate MRR' of the removal function. In addition, collect no more than 10 ml of the magnetorheological fluid in the test magnetorheological polishing equipment, and measure the particle size D of the iron powder in the magnetorheological fluid through the particle size measurement and medium content detection device F , the particle size D of the polishing powder C , the iron powder content FC, and the moisture content MC. It should be noted that the volume of the collected magnetorheological fluid shall not affect the supply and recovery of the magnetorheological fluid between the supply system and the processing magnetorheological polishing equipment and the test magnetorheological polishing equipment, that is, it shall not affect the smooth flow of the magnetorheological fluid between the processing magnetorheological polishing equipment, the test magnetorheological polishing equipment, and the supply system.

[0047] In the current data acquisition time, if the measured pressure P', flow rate Q, force F, and ribbon thickness H are all within the corresponding allowable ranges, that is: P' ∈ [P' min , P' max , Q ∈ [Q min , Q max , F ∈ [F min , F max , and H ∈ [H min , H max , further compare the current true volume removal rate MRR' of the removal function and the magnetorheological fluid composition information: (1) If the current magnetorheological fluid composition information is all within the corresponding allowable ranges, and the current true volume removal rate MRR' of the removal function is within the removal rate allowable range [MRR min , MRR maxWithin this range, the next data acquisition time interval remains ΔT1, that is, after another interval of ΔT1, the composition information of the magnetorheological fluid and the true volume removal rate MRR' of the removal function are acquired again. (2) If all the current composition information of the magnetorheological fluid is within the corresponding allowable range, but the current true volume removal rate MRR' of the removal function is not within the allowable range of the removal rate [MRR min , MRR max , the next data acquisition time interval is ΔT2, that is, after an interval of ΔT2, the composition information of the magnetorheological fluid and the true volume removal rate MRR' of the removal function are acquired. (3) If any one of the current composition information of the magnetorheological fluid exceeds the corresponding allowable range (that is, any one of the particle size D of the iron powder F , the particle size D of the polishing powder C , the content FC of the iron powder, and the content MC of the moisture exceeds the corresponding allowable range), but the current true volume removal rate MRR' of the removal function is within the allowable range of the removal rate [MRR min , MRR max , the next data acquisition time interval is ΔT3, that is, after an interval of ΔT3, the composition information of the magnetorheological fluid and the true volume removal rate of the removal function are acquired; (4) If any one of the current composition information of the magnetorheological fluid exceeds the corresponding allowable range, and the current true volume removal rate MRR' of the removal function is not within the allowable range of the removal rate [MRR min , MRR max , the next data acquisition time interval is ΔT4, that is, after an interval of ΔT4, the composition information of the magnetorheological fluid and the true volume removal rate MRR' of the removal function are acquired; in the current data acquisition time, if any one or several of the measured pressure P', flow rate Q, force F, and ribbon thickness H are not within the corresponding allowable ranges, the current true volume removal rate MRR' and the composition information of the magnetorheological fluid are further compared: (5) If all the current composition information of the magnetorheological fluid is within the corresponding allowable range, and the current true volume removal rate MRR' of the removal function is within the allowable range of the removal rate [MRR min , MRR max , the next data acquisition time interval is ΔT5, that is, after another interval of ΔT5, the composition information of the magnetorheological fluid and the true volume removal rate MRR' of the removal function are acquired again. (6) If any one of the current composition information of the magnetorheological fluid exceeds the corresponding allowable range, and the current true volume removal rate MRR' of the removal function is within the allowable range of the removal rate [MRR min , MRR maxWithin it, the next data acquisition time interval is ΔT6, that is, the magnetorheological fluid composition information and the true removal function volume removal rate MRR' are acquired at an interval of ΔT6; (7) If all the current magnetorheological fluid composition information is within the corresponding allowable ranges, but the current true removal function volume removal rate MRR' is not within the removal rate allowable range [MRR min , MRR max , the next data acquisition time interval is ΔT7, that is, the magnetorheological fluid composition information and the true removal function volume removal rate MRR' are acquired at an interval of ΔT7; (8) If any one of the current magnetorheological fluid composition information exceeds the corresponding allowable range, and the current true removal function volume removal rate MRR' is not within the removal rate allowable range [MRR min , MRR max , the next data acquisition time interval is ΔT8, that is, the magnetorheological fluid composition information and the true removal function volume removal rate MRR' are acquired at an interval of ΔT8.

[0048] The data acquisition time intervals ΔT1 to ΔT8 are determined according to the actual situation.

[0049] The present invention comprehensively measures the various parameters of the magnetorheological fluid and the change of the removal function of the magnetorheological polishing system during the long-term processing to obtain the removal function information of the optical element to be processed, which provides important data support for judging the surface shape error distribution of the optical element to be processed after processing, and provides data support for the change of the virtual processing removal function of the optical element to be processed and guidance for the selection of processing parameters and processing strategies for further long-term processing.

[0050] S3: Exchange the blocked pipelines in the processing magnetorheological polishing system and the test magnetorheological polishing system; restart the processing magnetorheological polishing system to process the optical element to be processed; install the cleaned pipeline into the test magnetorheological polishing system; restart the test magnetorheological polishing system to process the test optical element; return to step S2.

[0051] Combining with the shunt-designed magnetorheological removal function change measurement device described in the embodiments of the present invention, it can be understood that in step S3, the stop valves are controlled to close the pipelines in the processing magnetorheological polishing system and the test magnetorheological polishing system, and the blocked pipelines in the processing magnetorheological polishing system and the test magnetorheological polishing system are exchanged. After the exchange, restart the processing magnetorheological polishing system to process the optical element to be processed and clean the blocked pipeline. Install the cleaned pipeline into the test magnetorheological polishing system, restart the test magnetorheological polishing system to process the test optical element, and return to step S2 for monitoring the magnetorheological fluid and judging the blockage of the magnetorheological fluid.

[0052] It should be understood that the various forms of processes shown above can be used, with steps reordered, added or deleted. For example, the steps recited in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is imposed herein.

[0053] The above specific embodiments do not constitute a limitation on the protection scope of the present 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 the present invention shall be included within the protection scope of the present invention.

Claims

1. A measuring device for the change of the magnetorheological removal function with a shunt design, characterized in that It includes a processing magnetorheological finishing system, a testing magnetorheological finishing system, a supply system, and a control system; among which: The processing magnetorheological finishing system includes a robot, and a processing magnetorheological finishing device provided at the free end of the robot. The control system controls the robot and the processing magnetorheological finishing device to process the optical element. The processing magnetorheological finishing device measures in real time the flow condition of the magnetorheological fluid inside the processing magnetorheological finishing device during the processing, and transmits the measurement result to the control system; The testing magnetorheological finishing system includes a position adjustment table and a testing magnetorheological finishing device; the optical element is placed on the position adjustment table, and the control system controls the position adjustment table to adjust the processing position of the optical element; the control system controls the testing magnetorheological finishing device to cooperate with the position adjustment table to process the optical element, and measures in real time the flow condition of the magnetorheological fluid inside the testing magnetorheological finishing device during the processing, and transmits the measurement result to the control system; The supply system is controlled by the control system and supplies magnetorheological fluid to the processing magnetorheological finishing device and the testing magnetorheological finishing device simultaneously.

2. The magnetic rheological removal function change measuring device with a shunt design according to claim 1, characterized in that The processing magnetorheological finishing device and / or the testing magnetorheological finishing device includes: A magnetorheological finishing assembly for processing the optical element; A magnetorheological fluid flow measurement assembly for measuring in real time the flow condition of the magnetorheological fluid during the processing; A stop valve controlled by the control system to control the flow and transportation of the magnetorheological fluid.

3. The magnetorheological removal function change measuring device with a shunt design according to claim 2, characterized in that, The magnetorheological finishing assembly includes: A polishing wheel that contacts the optical element and cooperates with the magnetorheological fluid to process the optical element; A polishing motor controlled by the control system to drive the polishing motor; A nozzle connected to the supply system and supplying magnetorheological fluid to the polishing wheel; A magnet module for changing the stiffness of the magnetorheological fluid at the polishing wheel.

4. The magnetorheological removal function change measuring device with a shunt design according to claim 2, characterized in that, The magnetorheological fluid flow measurement assembly includes: A pressure sensor for measuring the pressure generated during the flow of the magnetorheological fluid and transmitting the measured pressure to the control system; An electromagnetic flowmeter for measuring the flow rate of the magnetorheological fluid and transmitting the measured flow rate to the control system.

5. The magnetorheological removal function change measurement device with a shunt design according to claim 1 or 2, characterized in that, The processing magnetorheological finishing system and / or the testing magnetorheological finishing system further includes: A force sensor for measuring in real time the change in the force between the magnetorheological fluid and the optical element and transmitting the measured force to the control system; A line laser measuring instrument for measuring in real time the change in the ribbon thickness of the magnetorheological fluid and transmitting the measured ribbon thickness to the control system.

6. The magnetorheological removal function change measuring device with shunt design according to claim 1, characterized in that The testing magnetorheological finishing system further includes a particle size measurement and medium content detection device; the particle size measurement and medium content detection device measures in real time the particle sizes of the iron powder and polishing powder in the magnetorheological fluid, as well as the contents of the iron powder, polishing powder, and moisture, and transmits the measured information to the control system; 7. The magnetorheological removal function change measuring device with a shunt design according to claim 1, characterized in that, The supply system includes: A liquid storage module for storing and stirring the magnetorheological fluid; A recycling module controlled by the control system to recycle the magnetorheological fluid and transport the recycled magnetorheological fluid to the liquid storage module; The supply module, controlled by the control system, transports the magnetorheological fluid in the liquid storage module to the processing magnetorheological polishing equipment and / or the testing magnetorheological polishing equipment.

8. A measurement method for the change of magnetorheological removal function with shunt design, according to the magnetorheological removal function change measurement device with shunt design described in any one of claims 1 to 7, characterized in that, It includes: S1: Control the supply system to transport the magnetorheological fluid to the processing magnetorheological polishing system and the testing magnetorheological polishing system, and control the processing magnetorheological polishing system and the testing magnetorheological polishing system to process the optical element to be processed and the testing optical element respectively; S2: Monitor the change of the magnetorheological fluid in the processing magnetorheological polishing system in real time, and judge whether there is a blockage of the magnetorheological fluid in the processing magnetorheological polishing system; if a blockage occurs, execute step S3, otherwise repeat step S2 until the processing of the optical element to be processed is completed; S3: Exchange the pipelines corresponding to the blockage in the processing magnetorheological polishing system and the testing magnetorheological polishing system, restart the processing magnetorheological polishing system to process the optical element to be processed; install the cleaned pipeline into the testing magnetorheological polishing system, restart the testing magnetorheological polishing system to process the testing optical element; return to step S2.

9. The method for measuring the change of the magnetorheological removal function with shunt design according to claim 8, characterized in that, In step S2, determine the allowable pressure range of the magnetorheological fluid in the processing magnetorheological polishing system; in the processing magnetorheological polishing system, if the current pressure of the magnetorheological fluid does not exceed the allowable pressure range, it is determined that there is no blockage of the magnetorheological fluid, and step S2 is repeated; if the current pressure of the magnetorheological fluid exceeds the allowable pressure range, it is determined that there is a blockage of the magnetorheological fluid, and step S3 is executed.

10. The method for measuring the change of the magnetorheological removal function with shunt design according to claim 9, characterized in that Step S2 also includes: In the current data acquisition time, monitor the processing information of the testing magnetorheological polishing system on the testing optical element and the composition information of the magnetorheological fluid in the testing magnetorheological polishing system; Determine the removal function information of the optical element to be processed according to the current processing information; Determine the next data acquisition time for the removal function information and the composition information of the magnetorheological fluid according to the current removal function information and the composition information of the magnetorheological fluid.

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