Magnetorheological polishing equipment and method based on force sensor adjustment

Abstract

The present invention relates to the field of optical processing technology, and in particular to a magnetorheological polishing device and method based on force sensor adjustment. The device includes a robot, a control unit, a magnetorheological processing module and a force sensor; wherein the magnetorheological processing module is arranged at the end of the robot, and the force sensor is arranged between the magnetorheological processing module and the robot; the robot drives the magnetorheological processing module to process an optical element, and during the processing, the force sensor measures the processing force applied to the optical element by the magnetorheological processing module; in the method, the real-time change of the magnetorheological processing force during the processing is measured by the force sensor, and the supply system, nozzle and actuator group in the magnetorheological processing module are adjusted in real time, thereby realizing real-time constant control of the removal function.

Description

Technical Field

[0001] The present invention belongs to the field of optical processing technology, and in particular relates to a magnetorheological polishing device and method based on force sensor adjustment. Background Art

[0002] Magnetorheological finishing (MRF) is an advanced optical manufacturing technology that has developed in recent years. It boasts numerous advantages, including stable removal function, controllable edge effects, minimal subsurface damage, no photocopying, strong reshaping capabilities, and high machining accuracy. Consequently, MRF has garnered widespread attention in high-precision optical processing. Existing MRF processes primarily integrate MRF modules onto CNC machine tools. However, CNC machine tools have several limitations (such as low degrees of freedom, large footprint, and high cost), which limit the deviation of aspheric surfaces and make precise position control along the surface normal difficult. In response to these shortcomings of CNC machine tools, researchers have introduced six-degree-of-freedom industrial robots into the field of optical processing in recent years. Six-degree-of-freedom industrial robots have the advantages of high degrees of freedom, small footprint, large processing range and low cost, which make up for the shortcomings of CNC machine tools. Therefore, when the magnetorheological polishing module is integrated into the industrial robot, theoretically, high-precision processing of large-aperture complex curved optical components can be achieved. However, when the industrial robot is combined with the magnetorheological polishing module, there are factors such as processing, assembly, load, trajectory planning and reduction ratio, which lead to low execution accuracy of the robot end and large changes in the polishing gap during the processing. At the same time, magnetorheological polishing technology is an optical processing technology with high determinism of the removal function. It has high requirements for the change of the polishing gap during the polishing process. Generally, the polishing gap of the magnetorheological CNC machining center varies in tens of microns (PV<0.1mm), while the trajectory accuracy of common commercial robots is generally in the sub-millimeter to millimeter range, which leads to large changes in the polishing gap during the processing. Large changes in the polishing gap will lead to a decrease in the certainty of the removal function, which in turn affects the final processing accuracy. Therefore, the motion accuracy of currently commercial large-scale six-degree-of-freedom industrial robots often does not meet the requirements of magnetorheological polishing technology for changes in the removal function during high-precision polishing.

[0003] To address the issue of low robot motion precision, real-time control solutions for constant-force grinding and polishing have become a research hotspot. Force-position control has become a common method for controlling constant-force robot grinding and polishing. A common application involves placing a force sensor between the machining tool and the robot. By measuring force changes, the position error is calculated. Constant-force control is then achieved by compensating for this position error using the robot itself or other motion compensation mechanisms. Summary of the Invention

[0004] In view of this, the present invention aims to provide a magnetorheological polishing device and method based on force sensor adjustment, which measures the real-time changes in force during magnetorheological processing through force sensors, and performs real-time regulation of the supply system, nozzle and actuator in the magnetorheological processing module, thereby achieving real-time constant control of the removal function.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0006] A magnetorheological polishing device based on force sensor regulation includes a robot, a control unit, an actuator group, a magnetorheological processing module, and a force sensor. The actuator group is connected to the end of the robot via the force sensor. The magnetorheological processing module is arranged at the output end of the actuator group, so that the robot and the actuator group drive the magnetorheological processing module to process the optical element. During the processing, the force sensor measures the force applied by the polishing wheel in the magnetorheological processing module to the optical element.

[0007] The interior of the control unit includes:

[0008] a conversion relationship module, which obtains a first conversion relationship based on a force value collected by the force sensor and a first position of a supply system in the magnetorheological processing module, and obtains a second conversion relationship based on the force value and a second position of a nozzle in the magnetorheological processing module;

[0009] a processing program module, which obtains a processing program according to a removal function generated when the magnetorheological processing module processes the optical element, and imports the processing program into the magnetorheological processing module;

[0010] The real-time control module adjusts the actuator group, or adjusts the first position according to the first conversion relationship, or adjusts the second position according to the second conversion relationship, or adjusts the removal function during the processing in combination with the processing program to stabilize the removal function during the processing of the optical element.

[0011] Furthermore, the magnetorheological processing module also includes a transmission belt, a polishing motor, a magnet and a magnetorheological mounting frame; wherein, the magnetorheological mounting frame is arranged on the output end of the actuator group, and the polishing wheel is arranged on the magnetorheological mounting frame; the polishing motor is arranged on the magnetorheological mounting frame and connected to the polishing wheel through a transmission belt, so that the polishing motor controls the rotation of the polishing wheel; the nozzle is installed on the magnetorheological mounting frame along the rotation direction of the polishing wheel through the nozzle mounting seat, and the nozzle mounting seat adjusts the installation angle of the nozzle, thereby changing the second position; the supply system delivers magnetorheological fluid to the nozzle; the magnet is arranged on the magnetorheological mounting frame and close to the working point of the polishing wheel, so that the magnetorheological fluid is affected by the magnetic field strength of the magnet to change the stiffness of the magnetorheological fluid, thereby processing the optical element.

[0012] Furthermore, the supply system includes a liquid pump, a supply mounting bracket, a supply motor and a screw; wherein, the supply motor and the screw are arranged on the supply mounting bracket, so that the supply motor drives the screw to rotate; the liquid pump is arranged on the nut of the screw, so that the screw drives the liquid pump to move along the screw, thereby changing the first position; the liquid pump transports magnetorheological fluid to the nozzle through the pipeline.

[0013] Furthermore, the nozzle mounting bracket includes a fixing bracket, a nozzle adjustment motor, a push rod, and a nozzle support bracket; wherein, the fixing bracket is arranged on the magnetorheological mounting bracket, and an arc slide rail is arranged on the inner side wall of the fixing bracket; the nozzle adjustment motor is arranged on the magnetorheological mounting bracket, and one end of the push rod passes through the fixing bracket and is connected to the nozzle adjustment motor, so that the nozzle adjustment motor pushes the slider on the arc slide rail to move through the push rod; one end of the nozzle support bracket is arranged on the slider, and the nozzle is connected to the other end of the nozzle support bracket, so that the nozzle adjustment motor pushes the slider through the push rod, and then the nozzle support bracket drives the nozzle to move, thereby completing the adjustment of the second position.

[0014] Furthermore, the force sensor, the robot, the actuator group, the nozzle adjustment motor and the supply motor are respectively connected to the control unit to form respective communication lines, so that the control unit receives and sends signals through the corresponding communication lines.

[0015] A magnetorheological polishing method for adjusting the position of a supply system, based on a magnetorheological polishing device based on force sensor adjustment provided by the present invention, comprises the following steps:

[0016] A1: Control the polishing wheel to process the test optical element with different polishing gaps, and use the force sensor to record the force changes at each processing point. The third conversion relationship between force and polishing gap is obtained in the conversion relationship module;

[0017] A2: Changing the first position, controlling the polishing wheel to process different positions of the test optical element with different polishing gaps, maintaining a constant force during the processing, and obtaining a fourth conversion relationship between the polishing gap and the first position in the conversion relationship module;

[0018] A3: In the conversion relationship module, a first conversion relationship is calculated based on the third conversion relationship and the fourth conversion relationship;

[0019] A4: Setting a force change threshold and a maximum first position; controlling the magnetorheological processing module to process the optical element to be processed by combining the first conversion relationship, the force change threshold and the maximum first position, and adjusting the first position in real time by the real-time control module during the processing.

[0020] Further, in step A4, the magnetorheological processing module is controlled to move to the current processing position When the current force measured by the force sensor Force change threshold For comparison:

[0021] If the current force Less than the force change threshold , not the current first position Make adjustments;

[0022] If the current force Greater than or equal to the force change threshold , for the current first position Make adjustments:

[0023] If the current first position Less than the maximum first position , for the current first position Adjust according to the following formula:

[0024]

[0025] in, Indicates the first conversion relationship;

[0026] If the current first position Greater than or equal to the maximum first position , the current first position Adjust to the maximum first position .

[0027] A nozzle-adjusted magnetorheological polishing method, based on the magnetorheological polishing device based on force sensor adjustment provided by the present invention, comprises the following steps:

[0028] B1: Control the polishing wheel to process the test optical element with different polishing gaps, and use the force sensor to record the force changes at each processing point. The fifth conversion relationship between force and polishing gap is obtained in the conversion relationship module;

[0029] B2: Keeping the force constant, the second position is changed separately under different polishing gaps, and processing is performed at different positions of the test optical element, and a sixth conversion relationship between the polishing gap and the second position is obtained in the conversion relationship module;

[0030] B3: In the conversion relationship module, a second conversion relationship is calculated based on the fifth conversion relationship and the sixth conversion relationship;

[0031] B4: Setting the force change threshold and the maximum second position; combining the second conversion relationship, the force change threshold and the maximum second position, controlling the magnetorheological processing module to process the optical element to be processed, and during the processing, the real-time control module to adjust the second position in real time.

[0032] Further, in step B4, the magnetorheological processing module is controlled to move to the current processing position. When the current force measured by the force sensor Force change threshold For comparison:

[0033] If the current force Less than the force change threshold , not the current second position Make adjustments;

[0034] If the current force Greater than or equal to the force change threshold , for the current second position Make adjustments:

[0035] If the current second position Less than the maximum second position , current second position Adjust according to the following formula:

[0036]

[0037] in, Represents the second conversion relationship;

[0038] If the current second position Greater than or equal to the maximum second position , change the current second position Adjust to the second maximum position .

[0039] A magnetorheological polishing method with a variable removal function, based on a magnetorheological polishing device based on force sensor adjustment provided by the present invention, comprises the following steps:

[0040] C1: Control the polishing wheel to process the test optical element with different polishing gaps to obtain the removal function. At the same time, the force changes at each processing point are recorded by the force sensor during the processing, and the seventh conversion relationship between the volume removal rate of the removal function and the force at each processing point is obtained in the conversion relationship module.

[0041] C2: Using the machining program module to obtain the machining program according to the removal function, and importing the machining program into the magnetorheological machining module;

[0042] C3: Setting the force change threshold and the maximum force value; combining the seventh conversion relationship, the force change threshold and the maximum force value, controlling the magnetorheological machining module to process the optical element to be machined, and calculating the removal function of each machining point during the machining process, obtaining a variable removal function set, and then generating a new machining program;

[0043] C4: Import the new processing program into the magnetorheological processing module, and then perform secondary processing on the optical component to be processed.

[0044] Furthermore, obtaining the seventh conversion relationship in step C1 includes the following steps:

[0045] C11: Control the polishing wheel to process the test optical element with different polishing gaps, and use the force sensor to record the corresponding force changes at each processing point. In the conversion relationship module, the following is obtained:

[0046]

[0047] in, Expressive power Polishing gap The eighth conversion relationship between;

[0048] C12: Control the polishing wheel to process different positions of the test optical element with different polishing gaps, and calculate the removal function volume removal rate of each processing point. The following is obtained in the conversion relationship module:

[0049]

[0050] in, Represents the removal function volume removal rate Polishing gap The ninth conversion relationship between;

[0051] C13: In the conversion relationship module, a seventh conversion relationship is calculated based on the eighth conversion relationship and the ninth conversion relationship, namely:

[0052]

[0053] in, Represents the seventh conversion relationship.

[0054] Further, in step C3, the magnetorheological processing module is controlled to move to the current processing position When the current force measured by the force sensor Force change threshold For comparison:

[0055] If the current force Less than the force change threshold , the change of the current removal function is not calculated;

[0056] If the current force Greater than or equal to the force change threshold , calculate the change of the current removal function:

[0057] If the current force Less than the maximum force , calculate the current processing point by the following formula The corresponding removal function , and then get the set of variable removal functions :

[0058]

[0059] in, Indicates the current processing point The corresponding removal function volume removal rate;

[0060] If the current force Greater than or equal to the maximum force , the current processing point is obtained by the following formula The corresponding removal function , and then get the set of variable removal functions :

[0061]

[0062] in, Indicates maximum force The corresponding maximum removal function volume removal rate.

[0063] An actuator-regulated magnetorheological polishing method, based on the force sensor-regulated magnetorheological polishing device provided by the present invention, comprises the following steps:

[0064] D1: Set the force change threshold and the maximum value control of the actuator group;

[0065] D2: Control the magnetorheological processing module to move to the current processing position When the current force measured by the force sensor is compared with the force change threshold: if the current force is less than the force change threshold, execute step D4; if the current force is greater than the force change threshold, execute step D3;

[0066] D3: If the current position change of the polishing wheel is less than the maximum value control, the output displacement of the actuator group is controlled to be the current position change, and the optical element to be processed is processed; if the current position change of the polishing wheel is greater than the maximum value control, the output displacement of the actuator group is controlled to be the maximum value control, and the optical element to be processed is processed;

[0067] D4: Control the magnetorheological processing module to move to the next processing position, and repeat steps D2 and D3 until the magnetorheological processing module is controlled to traverse all processing points on the optical element to be processed.

[0068] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0069] In the magnetorheological polishing equipment and method based on force sensor adjustment created by the present invention, the force sensor is used to measure in real time the force applied by the magnetorheological processing module to the optical element during six-dimensional processing driven by the robot, thereby performing real-time regulation of the supply system, nozzle and actuator group in the magnetorheological processing module, thereby achieving real-time constant control of the removal function changes under multi-factor coupling during the processing of the optical element; at the same time, the acquisition of posture information does not need to rely on the actual processing process, and the posture error information of the processing equipment can be obtained during the processing trial run (in which magnetorheological fluid is not introduced and no processing effect is produced), and there is no need to place the measuring equipment at the lowest point of the polishing wheel, which will not affect the actual processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0071] Figure 1 A schematic structural diagram of a magnetorheological polishing device based on force sensor adjustment according to an embodiment of the present invention from one perspective;

[0072] Figure 2 A schematic structural diagram of a magnetorheological polishing device based on force sensor adjustment according to an embodiment of the present invention from another perspective;

[0073] Figure 3 A schematic structural diagram of the actuator according to an embodiment of the present invention;

[0074] Figure 4 A schematic diagram of the structure of the supply system according to an embodiment of the present invention;

[0075] Figure 5 A schematic structural diagram of a liquid pump according to an embodiment of the present invention;

[0076] Figure 6 This is a schematic structural diagram of the nozzle mounting seat described in an embodiment of the present invention.

[0077] Description of reference numerals:

[0078] 1. Robot; 2. Control unit; 3. Force sensor; 4. High-frequency actuator; 5. Laboratory bench; 6. Optical element to be processed; 7. Optical element to be tested; 8. Supply system; 9. Nozzle; 10. Polishing wheel; 11. Drive belt; 12. Polishing motor; 13. Magnet; 14. Magnetorheological mounting bracket; 15. Nozzle mounting base; 16. Liquid pump; 17. Supply mounting bracket; 18. Supply motor; 19. Lead screw; 20. Mounting plate; 21. Slide rail; 22. , liquid pump body; 23. Cooling chamber; 24. Magnetorheological fluid storage chamber; 25. Cooling water inlet; 26. Magnetorheological fluid inlet; 27. Cooling water outlet; 28. Magnetorheological fluid outlet; 29. ​​Nozzle support frame; 30. Nozzle adjustment motor; 31. Fixed frame; 32. Push rod; 33. Slider; 34. Arc slide rail; 35. Transition plate; 36. Cylinder body; 37. Cavity A; 38. Cavity B; 39. Oil scraper ring; 40. Connecting plate; 41. Moving piston. DETAILED DESCRIPTION

[0079] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is 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 only used to explain the present invention and do not constitute a limitation of the present invention.

[0080] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0081] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like 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, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0082] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0083] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0084] like Figure 1 and Figure 2 As shown, the force sensor-regulated magnetorheological polishing device described in the embodiment of the present invention includes a robot 1, a control unit 2, a magnetorheological processing module, a force sensor 3, and an actuator assembly. The actuator assembly is disposed at the end of the robot 1, and the force sensor 3 is disposed on the actuator assembly and the robot 1. The magnetorheological processing module is mounted on the output end of the actuator assembly, so that the robot 1 and the actuator assembly drive the magnetorheological processing module to process the optical element 6 to be processed or the test optical element 7 placed on the experimental table 5. During the processing, the force sensor 3 measures the force applied by the polishing wheel 10 in the magnetorheological processing module to the optical element 6 to be processed or the test optical element 7. In this embodiment of the present invention, the force sensor 3 is preferably disposed between the actuator assembly and the robot 1, which simplifies the mechanical structure and reduces the weight of the magnetorheological processing module. In addition, by connecting the magnetorheological processing module and the robot 1 to both sides of the force sensor 3, the force balance of the force sensor 3 is ensured, extending the service life of the force sensor 3, thereby reducing the complexity and cost of the device, while improving the device assembly accuracy and the final device motion accuracy.

[0085] In the embodiment of the present invention, the actuator group is composed of two cascaded high-frequency actuators 4, that is, one high-frequency actuator 4 is installed on the output end of the other high-frequency actuator 4, so that the total output displacement of the actuator group is the sum of the output displacements of the two high-frequency actuators 4. In the embodiment of the present invention, the high-frequency actuator 4 is preferably an SG model static pressure linear cylinder produced by Jilin Huakong Testing Instrument Co., Ltd. The structure of each high-frequency actuator 4 is as follows: Figure 3As shown, it includes a transition plate 35, a cylinder body 36, a cavity A 37, a cavity B 38, an oil scraper ring 39, a connecting plate 40, and a moving piston 41. The transition plate 35 is used to connect the end flange of the robot 1 and the cylinder body 36 of the high-frequency actuator 4. The cavity A 37 and the cavity B 38 are used to control the inflow and outflow of hydraulic oil. The oil scraper ring 39 is used to prevent the hydraulic oil from flowing out of the cylinder body 36. The moving piston 41 is used to output position. The connecting plate 40 is used to connect the moving piston 41 to the magnetorheological processing module or another high-frequency actuator 4, thereby outputting displacement to the magnetorheological processing module or another high-frequency actuator 4.

[0086] The control unit 2 internally includes a conversion relationship module, a processing program module, and a real-time control module. The conversion relationship module generates a first conversion relationship based on the force value collected by the force sensor 3 and the first position of the supply system 8 in the magnetorheological processing module, and a second conversion relationship based on the force value and the second position of the nozzle 9 in the magnetorheological processing module. In this embodiment of the present invention, the first position of the supply system 8 is defined as the vertical distance between the nozzle opening of the nozzle 9 and the working point of the supply system 8 (i.e., the liquid outlet of the supply system 8). A change in the vertical distance between the nozzle opening of the nozzle 9 and the working point of the supply system 8 causes a change in the flow rate, thereby causing a change in the removal function. The second position of the nozzle 9 is defined as the vertical distance between the nozzle opening of the nozzle 9 and the working point of the polishing wheel 10 (i.e., the closest point between the polishing wheel 10 and the surface of the optical element 6 or test optical element 7 along the normal direction to the surface of the optical element 6 or test optical element 7). The processing program module is used to generate a processing program based on the removal function generated when the magnetorheological processing module processes the optical element 6 or test optical element 7 and import the processing program into the magnetorheological processing module. The real-time control module is used to adjust the actuator group, or adjust the first position according to the first conversion relationship, or adjust the second position according to the second conversion relationship, or adjust the removal function during the processing in combination with the processing program to stabilize the removal function during the processing of optical elements.

[0087] In the embodiment of the present invention, the structure of the supply system 8 is as follows: Figure 1 、 Figure 2 and Figure 4As shown, the device includes a liquid pump 16, a supply mounting bracket 17, a supply motor 18, and a lead screw 19. The lead screw 19 is combined with a nut with a ball bearing thereon to form a ball screw. The supply motor 18 and the lead screw 19 are mounted on the supply mounting bracket 17, and the output end of the supply motor 18 is connected to one end of the lead screw 19, so that the supply motor 18 drives the lead screw 19 to rotate. The liquid pump 16 is mounted on a moving block of the lead screw 19, so that the lead screw 19 drives the liquid pump 16 to move, thereby changing the first position. Specifically, the lead screw 19 is provided with a nut that is compatible with the lead screw 19, and the nut has a ball bearing therein. The lead screw 19 and the nut together form a ball screw, and the moving block is fixed to the nut. When the lead screw 19 rotates, the cooperation between the lead screw 19 and the nut drives the moving block to move along the lead screw 19, thereby enabling the lead screw 19 to drive the liquid pump 16 to move. The liquid pump 16 delivers the magnetorheological fluid to the nozzle 9 through a pipeline. In an embodiment of the present invention, in order to enable the liquid pump 16 to move smoothly along the direction of the lead screw 19 without offset, a slide rail 21 parallel to the lead screw 19 is installed on both sides of the lead screw 19, and the liquid pump 16 is fixedly connected to the moving block of the lead screw 19 and the sliders on the two slide rails 21 through the installation fixing plate 20, so that the supply motor 18 drives the lead screw 19, and the lead screw 19 cooperates with the two slide rails 21 to drive the installation fixing plate 20 and the liquid pump 16 on the installation fixing plate 20 to move smoothly.

[0088] The liquid pump body 22 of the liquid pump 16 in the embodiment of the present invention is a DFLD vertical multi-stage pump manufactured by Shanghai Dongfang Pump Industry Co., Ltd. The structure of the entire liquid pump 16 is as follows: Figure 5 As shown, it includes a liquid pump body 22, a cooling chamber 23, and a magnetorheological fluid storage chamber 24. The liquid pump body 22 is used to supply magnetorheological fluid; the cooling chamber 23 is mainly used to store cooling water and cool the magnetorheological fluid; the magnetorheological fluid storage chamber 24 is mainly used to store magnetorheological fluid. When the liquid pump 16 is working, cooling water enters the cooling chamber 23 from the cooling water inlet 25 to cool the magnetorheological fluid, and the magnetorheological fluid enters the liquid pump body 22 from the magnetorheological fluid inlet 26 through the magnetorheological fluid storage chamber 24; the cooling water completes cooling the magnetorheological fluid in the liquid cooling chamber 23 and is discharged from the cooling water outlet 27; the cooled magnetorheological fluid is output from the magnetorheological fluid outlet 28 and transported to the nozzle 9 through the pipeline. At this time, the outlet of the supply system 8 is the magnetorheological fluid outlet 28. Furthermore, the first position of the supply system 8 is the vertical distance between the nozzle opening of the nozzle 9 and the magnetorheological fluid outlet 28.

[0089] The magnetorheological processing module also includes a transmission belt 11, a polishing motor 12, a magnet 13 and a magnetorheological mounting frame 14. The magnetorheological mounting frame 14 is fixedly mounted on the output end of the actuator group, and the polishing wheel 10 is arranged on the magnetorheological mounting frame 14. The polishing motor 12 is mounted on the magnetorheological mounting frame 14, and the output end of the polishing motor 12 is connected to the bearing of the polishing wheel 10 through the transmission belt 11, so that the polishing motor 12 controls the polishing wheel 10 to rotate. The manner in which the polishing motor 12 drives the polishing wheel 10 to rotate in the embodiment of the present invention can refer to the invention patent application with Chinese patent publication number CN118322074A, publication date July 12, 2024, and patent name "Self-rotating Polishing Module Processing System". The nozzle 9 is mounted on the magnetorheological mounting frame 14 along the rotation direction of the polishing wheel 10 through the nozzle mounting seat 15. The nozzle mounting seat 15 adjusts the installation angle of the nozzle 9, thereby changing the second position of the nozzle mouth of the nozzle 9. Supply system 8 delivers magnetorheological fluid to nozzle 9 via a pipeline. Nozzle 9 sprays the magnetorheological fluid toward the working point of polishing wheel 10, allowing polishing wheel 10 to process the optical element 6 or test optical element 7 using the magnetorheological fluid as a medium. Magnet 13 is mounted on magnetorheological mounting frame 14 near the working point of polishing wheel 10, so that the magnetic field strength of magnet 13 affects the magnetorheological fluid, changing its stiffness.

[0090] The structure of the nozzle mounting seat 15 is as follows Figure 6 As shown. Figure 6 (a) shows a schematic structural diagram of the nozzle 9 when it is installed on the nozzle mounting seat 15. Figure 6 (b) in the figure shows a schematic diagram of the structure when the nozzle 9 is not installed on the nozzle mounting base 15. In the nozzle mounting base 15, the fixing frame 31 is an L-shaped structure fixed to the magnetorheological mounting base 14. A circular arc slide 34 is arranged on the inner side wall of the fixing frame 31. The nozzle adjustment motor 30 is mounted on the magnetorheological mounting base 14. One end of the push rod 32 passes through the bottom edge of the fixing frame 31 and is connected to the output end of the nozzle adjustment motor 30. The nozzle adjustment motor 30 pushes the push rod 32, which in turn pushes the slider 33 on the circular arc slide 34 along the circular arc slide 34. One end of the nozzle support frame 29 is fixed to the slider 33, and the nozzle 9 is mounted on the other end of the nozzle support frame 29. When controlling the nozzle mounting base 15 to adjust the position of the nozzle 9, the nozzle adjustment motor 30 outputs a displacement, causing the push rod 32 to push the slider 33, which in turn causes the nozzle support frame 29 to move the nozzle 9, thereby adjusting the nozzle 9 to the second position.

[0091] The robot 1, force sensor 3, supply system 8, actuator assembly, and nozzle mounting bracket 15 are each connected to the control unit 2 to form a communication circuit, enabling the control unit 2 to receive and send signals via the corresponding communication circuit. Specifically, the control unit 2 is in communication with the supply motor 18 via a circuit. During operation, the control unit 2 sends control instructions to the supply motor 18, which drives the lead screw 19 to rotate. The rotating lead screw 19 drives the mounting plate 20 up and down, thereby changing the vertical position of the liquid pump 16 and thus the first position of the supply system 8. The control unit 2 controls the hydraulic oil pressure in the high-frequency actuator 4, thereby controlling the extension and retraction of the moving piston 41 to achieve position control of the magnetorheological processing module, thereby changing the output of the actuator assembly. The control unit 2 controls the nozzle adjustment motor 30 to change the position of the nozzle support frame 29, which moves along the arc slide 34, thereby changing the second position of the nozzle 9. Because the polishing wheel 10 generates a strong magnetic field during polishing, the communication circuit avoids this strong magnetic field.

[0092] Based on the magnetorheological polishing equipment based on force sensor adjustment described in the embodiment of the present invention, the embodiment of the present invention also provides a magnetorheological polishing method based on force sensor adjustment, which includes a magnetorheological polishing method with supply system position adjustment, a magnetorheological polishing method with nozzle adjustment, a magnetorheological polishing method with variable removal function, and a magnetorheological polishing method with actuator adjustment.

[0093] Specific embodiment 1: The magnetorheological polishing method for adjusting the position of the supply system provided in this specific embodiment is based on the magnetorheological polishing device based on force sensor adjustment described in the embodiment of the invention, combined with Figure 1 、 Figure 2 and Figure 4 , including the following steps:

[0094] A1: Control the polishing wheel 10 to process the test optical element 7 with different polishing gaps, and use the force sensor 3 to record the corresponding force changes at each processing point. The following is obtained in the conversion relationship module:

[0095]

[0096] in, Expressive power Polishing gap In this specific embodiment, the polishing wheel 10 is controlled to perform fixed-point processing on the test optical element 7 at different polishing gaps for a period of time.

[0097] A2: Change the first position and control the polishing wheel 10 to process different positions of the test optical element 7 with different polishing gaps. Keep the force unchanged during the processing. In the conversion relationship module, obtain:

[0098]

[0099] in, Indicates polishing gap With the first position In this embodiment, specifically, the first position is changed to control the polishing wheel 10 to perform fixed-point processing at different positions of the test optical element 7 with different polishing gaps for a period of time.

[0100] A3: In the conversion relationship module, the first conversion relationship is calculated based on the third conversion relationship and the fourth conversion relationship, that is:

[0101]

[0102] in, Indicates the first conversion relationship.

[0103] A4: Setting a force change threshold and a maximum first position; combining the first conversion relationship, the force change threshold, and the maximum first position, the magnetorheological processing module is controlled to process the optical element 6 to be processed. During the processing, the real-time control module adjusts the first position in real time. The force change threshold and the maximum first position are adaptively set based on actual conditions, and this embodiment does not impose any restrictions on this. The specific process of step A4 is as follows:

[0104] Control the magnetorheological processing module to move to the current processing position When the current force measured by force sensor 3 is Force change threshold For comparison:

[0105] If the current force Less than the force change threshold , not the current first position Make adjustments;

[0106] If the current force Greater than or equal to the force change threshold , for the current first position Make adjustments:

[0107] If the current first position Less than the maximum first position , for the current first position Adjust according to the following formula:

[0108]

[0109] If the current first position Greater than or equal to the maximum first position , the current first position Adjust to the maximum first position .

[0110] Specific embodiment 2: The nozzle adjustment magnetorheological polishing method provided in this specific embodiment is based on the magnetorheological polishing device based on force sensor adjustment described in the embodiment of the invention, combined with Figure 1 and Figure 2 ,as well as Figures 4 to 6 , including the following steps:

[0111] B1: Control the polishing wheel 10 to process the test optical element 7 with different polishing gaps, and use the force sensor 3 to record the force changes at each processing point. The following is obtained in the conversion relationship module:

[0112]

[0113] in, Expressive power Polishing gap In this embodiment, the polishing wheel 10 is controlled to perform fixed-point processing on the test optical element 7 at different polishing gaps for a period of time.

[0114] B2: Keeping the force constant, change the second position alone at different polishing gaps, and perform processing at different positions of the test optical element 7. Simultaneously, record the numerical changes of the polishing gap and the second position, and obtain the following in the conversion relationship module:

[0115]

[0116] in, Indicates polishing gap With the second position In this specific embodiment, specifically, the force is kept constant, the second position is changed independently under different polishing gaps, and fixed-point processing is performed at different positions of the test optical element 7 for a period of time.

[0117] B3: In the conversion relationship module, a second conversion relationship is calculated based on the fifth conversion relationship and the sixth conversion relationship, namely:

[0118]

[0119] in, Indicates the second conversion relationship.

[0120] B4: Setting the force change threshold and the maximum second position; combining the second conversion relationship, the force change threshold, and the maximum second position, the magnetorheological processing module is controlled to process the optical element 6 to be processed. During the processing, the real-time control module adjusts the second position in real time. The force change threshold and the maximum second position are adaptively set according to actual conditions, and this embodiment does not impose any restrictions on this. The specific process of step B4 is as follows:

[0121] Control the magnetorheological processing module to move to the current processing position When the current force measured by force sensor 3 is Force change threshold For comparison:

[0122] If the current force Less than the force change threshold , not the current second position Make adjustments;

[0123] If the current force Greater than or equal to the force change threshold , for the current second position Make adjustments:

[0124] If the current second position Less than the maximum second position , current second position Adjust according to the following formula:

[0125]

[0126] If the current second position Greater than or equal to the maximum second position , change the current second position Adjust to the second maximum position .

[0127] Specific embodiment 3: The magnetorheological polishing method with variable removal function provided in this specific embodiment is based on the magnetorheological polishing device based on force sensor adjustment described in the embodiment of the invention, combined with Figure 1 and Figure 2 , including the following steps:

[0128] C1: Control the polishing wheel 10 to process the test optical element 7 at different polishing gaps to obtain a removal function; simultaneously, during the processing, the force sensor 3 records the corresponding force changes at each processing point, and obtains the seventh conversion relationship between the volume removal rate of the removal function and the force at each processing point in the conversion relationship module. Specifically, the following steps are included:

[0129] C11: Control the polishing wheel 10 to process the test optical element 7 with different polishing gaps, and use the force sensor 3 to record the corresponding force changes at each processing point, and obtain the following in the conversion relationship module:

[0130]

[0131] in, Expressive power Polishing gap In this specific embodiment, the polishing wheel 10 is controlled to perform fixed-point processing on the test optical element 7 at different polishing gaps for a period of time.

[0132] C12: Control the polishing wheel 10 to process different positions of the test optical element 7 with different polishing gaps, and calculate the removal function volume removal rate of each processing point, and obtain the following in the conversion relationship module:

[0133]

[0134] in, Represents the removal function volume removal rate Polishing gap In this embodiment, the polishing wheel 10 is controlled to perform fixed-point processing at different positions of the test optical element 7 for a period of time with different polishing gaps.

[0135] C13: In the conversion relationship module, a seventh conversion relationship is calculated based on the eighth conversion relationship and the ninth conversion relationship, namely:

[0136]

[0137] in, Represents the seventh conversion relationship.

[0138] C2: Use the machining program module to obtain the machining program according to the removal function, and import the machining program into the magnetorheological machining module.

[0139] C3: Setting the force change threshold, maximum force, and maximum polishing gap of the polishing wheel 10; combining the seventh conversion relationship, the force change threshold, and the maximum force, controlling the magnetorheological processing module to process the optical element 6 to be processed. During the processing, the removal function of each processing point is calculated to obtain a set of variable removal functions, thereby generating a new processing program. The force change threshold, maximum force, and maximum polishing gap are adaptively set according to actual conditions, and this specific implementation does not impose any restrictions on this. The specific process of step C3 is as follows:

[0140] Control the magnetorheological processing module to move to the current processing position When the current force measured by force sensor 3 is Force change threshold For comparison:

[0141] If the current force Less than the force change threshold , the change of the current removal function is not calculated;

[0142] If the current force Greater than or equal to the force change threshold , the change of the current removal function is calculated as follows:

[0143] If the current force Less than the maximum force , calculate the current processing point by the following formula The corresponding removal function , and then get the set of variable removal functions :

[0144]

[0145] in, Indicates the current processing point The corresponding removal function volume removal rate;

[0146] If the current force Greater than or equal to the maximum force , the current processing point is obtained by the following formula The corresponding removal function , and then get the set of variable removal functions :

[0147]

[0148] in, Indicates maximum force The corresponding maximum removal function volume removal rate.

[0149] C4: Import the new processing program into the magnetorheological processing module, and then perform secondary processing on the optical element 6 to be processed.

[0150] Specific embodiment 4: The magnetorheological polishing method for adjusting the actuator provided in this specific embodiment is based on the magnetorheological polishing device based on force sensor adjustment described in the embodiment of the invention, combined with Figures 1 to 3 , including the following steps:

[0151] D1: Set the force change threshold and the maximum value of the actuator group. The force change threshold and maximum value can be set adaptively according to the actual situation. This specific implementation does not impose any restrictions on this.

[0152] D2: Control the magnetorheological processing module to move to the current processing position When the current force measured by force sensor 3 is Force change threshold For comparison:

[0153] If the current force Less than the force change threshold , without adjusting the current position of the polishing wheel 10, directly executing step D4;

[0154] If the current force Greater than or equal to the force change threshold , execute step D3 to adjust the current position of the polishing wheel 10.

[0155] D3: Change the current position of polishing wheel 10 Maximum value control of the actuator group For comparison:

[0156] If the current position of the polishing wheel 10 changes Less than maximum value control , the output displacement of the control actuator group is the current position change ,Right now:

[0157]

[0158] in, represents the sum of the output displacements of two cascaded high-frequency actuators, represents the output displacement of one of the cascaded high-frequency actuators, Represents the output displacement of another cascaded high-frequency actuator. The current polishing gap is:

[0159]

[0160] in, Indicates the polishing gap when the polishing wheel 10 is in the previous processing position and processes the optical element 6 to be processed;

[0161] If the current position of the polishing wheel 10 changes Greater than or equal to the maximum value control At this time, the output displacement of the actuator group is the maximum value control ,Right now:

[0162]

[0163] At this time, the current polishing gap of the polishing wheel 10 is:

[0164]

[0165] The optical element 6 to be processed is then processed.

[0166] D4: Control the magnetorheological processing module to move to the next processing position, and repeat step D2 until the magnetorheological processing module is controlled to traverse all processing points on the optical element 6 to be processed.

[0167] The conversion relationships in the above specific embodiments are all obtained by fitting. The fitting process includes but is not limited to importing discrete data into Matlab software, performing data fitting using Matlab's polyfit fitting command, and solving the respective conversion relationships. The Polyfit fitting command is a basic general command in Matlab software. This method can more intuitively see the corresponding relationship between the correlations and the corresponding function curves.

[0168] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present disclosure can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved. This is not limited herein.

[0169] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A magnetorheological polishing device based on force sensor adjustment, characterized in that: The device comprises a robot, a control unit, an actuator group, a magnetorheological processing module, and a force sensor; wherein the actuator group is connected to the end of the robot via the force sensor; the magnetorheological processing module is arranged at the output end of the actuator group, so that the robot and the actuator group drive the magnetorheological processing module to process the optical element, and during the processing, the force sensor measures the processing force applied by the polishing wheel in the magnetorheological processing module to the optical element; The interior of the control unit includes: a conversion relationship module, which obtains a first conversion relationship based on the force value collected by the force sensor and a first position of the supply system in the magnetorheological processing module, and obtains a second conversion relationship based on the force value and a second position of the nozzle in the magnetorheological processing module; a processing program module, which obtains a processing program according to a removal function generated when the magnetorheological processing module processes the optical element, and imports the processing program into the magnetorheological processing module; The real-time control module adjusts the actuator group, or adjusts the first position according to the first conversion relationship, or adjusts the second position according to the second conversion relationship, or adjusts the removal function during the processing in combination with the processing program, so that the removal function is stable during the processing of the optical element.

2. The magnetorheological polishing device based on force sensor adjustment according to claim 1 is characterized in that: The magnetorheological processing module also includes a transmission belt, a polishing motor, a magnet and a magnetorheological mounting frame; wherein, The magnetorheological mounting frame is arranged on the output end of the actuator assembly, and the polishing wheel is arranged on the magnetorheological mounting frame; The polishing motor is arranged on the magnetorheological mounting frame and is connected to the polishing wheel via the transmission belt, so that the polishing motor controls the polishing wheel to rotate; The nozzle is mounted on the magnetorheological mounting bracket along the rotation direction of the polishing wheel via a nozzle mounting bracket, and the nozzle mounting bracket adjusts the mounting angle of the nozzle to thereby change the second position; the supply system delivers the magnetorheological fluid to the nozzle; The magnet is arranged on the magnetorheological mounting frame and close to the working point of the polishing wheel, so that the magnetorheological fluid is affected by the magnetic field strength of the magnet and the rigidity of the magnetorheological fluid is changed, thereby processing the optical element.

3. The magnetorheological polishing device based on force sensor adjustment according to claim 2, characterized in that: The supply system includes a liquid pump, a supply mounting bracket, a supply motor and a screw; wherein, the supply motor and the screw are arranged on the supply mounting bracket, so that the supply motor drives the screw to rotate; the liquid pump is arranged on the nut of the screw, so that the screw drives the liquid pump to move along the screw, thereby changing the first position; the liquid pump transports magnetorheological fluid to the nozzle through a pipeline.

4. The magnetorheological polishing device based on force sensor adjustment according to claim 3 is characterized in that: The nozzle mounting seat includes a fixing frame, a nozzle adjustment motor, a pushing rod and a nozzle support frame; wherein, the fixing frame is arranged on the magnetorheological mounting frame, and an arc slide rail is arranged on the inner side wall of the fixing frame; the nozzle adjustment motor is arranged on the magnetorheological mounting frame, and one end of the pushing rod passes through the fixing frame and is connected to the nozzle adjustment motor, so that the nozzle adjustment motor pushes the slider on the arc slide rail to move through the pushing rod; one end of the nozzle support frame is arranged on the slider, and the nozzle is connected to the other end of the nozzle support frame, so that the nozzle adjustment motor pushes the slider through the pushing rod, and then the nozzle support frame drives the nozzle to move, thereby completing the adjustment of the second position.

5. The magnetorheological polishing device based on force sensor adjustment according to claim 4, characterized in that: The force sensor, the robot, the actuator group, the nozzle adjustment motor and the supply motor are respectively connected to the control unit to form respective communication lines, so that the control unit receives and sends signals through the corresponding communication lines.

6. A magnetorheological polishing method with supply system position adjustment, based on the magnetorheological polishing device based on force sensor adjustment according to any one of claims 1 to 5, characterized in that: The following steps are involved: A1: Controlling the polishing wheel to process the test optical element with different polishing gaps, and recording the force changes at each processing point by the force sensor, and obtaining a third conversion relationship between the force and the polishing gap in the conversion relationship module; A2: changing the first position, controlling the polishing wheel to process different positions of the test optical element with different polishing gaps, maintaining a constant force during the processing, and obtaining a fourth conversion relationship between the polishing gap and the first position in the conversion relationship module; A3: In the conversion relationship module, the first conversion relationship is calculated based on the third conversion relationship and the fourth conversion relationship; A4: Setting a force change threshold and a maximum first position; combining the first conversion relationship, the force change threshold and the maximum first position, controlling the magnetorheological processing module to process the optical element to be processed, and during the processing, the real-time control module adjusts the first position in real time.

7. The magnetorheological polishing method with supply system position adjustment according to claim 6, characterized in that: In step A4, the magnetorheological processing module is controlled to move to the current processing position. When the current force measured by the force sensor Force change threshold For comparison: If the current force Less than the force change threshold , not the current first position Make adjustments; If the current force Greater than or equal to the force change threshold , for the current first position Make adjustments: If the current first position Less than the maximum first position , for the current first position Adjust according to the following formula: in, represents the first conversion relationship; If the current first position Greater than or equal to the maximum first position , the current first position Adjust to the maximum first position .

8. A nozzle-adjustable magnetorheological polishing method, based on the force sensor-adjustable magnetorheological polishing device according to any one of claims 1 to 5, characterized in that: The following steps are involved: B1: Controlling the polishing wheel to process the test optical element with different polishing gaps, and recording the force changes at each processing point by the force sensor, and obtaining a fifth conversion relationship between the force and the polishing gap in the conversion relationship module; B2: maintaining the force constant, changing the second position individually under different polishing gaps, and performing processing at different positions of the test optical element, and obtaining a sixth conversion relationship between the polishing gap and the second position in the conversion relationship module; B3: In the conversion relationship module, the second conversion relationship is calculated based on the fifth conversion relationship and the sixth conversion relationship; B4: Setting a force change threshold and a maximum second position; combining the second conversion relationship, the force change threshold and the maximum second position, controlling the magnetorheological processing module to process the optical element to be processed, and during the processing, the real-time control module adjusts the second position in real time.

9. The nozzle-adjustable magnetorheological polishing method according to claim 8, characterized in that: In step B4, the magnetorheological processing module is controlled to move to the current processing position. When the current force measured by the force sensor Force change threshold For comparison: If the current force Less than the force change threshold , not the current second position Make adjustments; If the current force Greater than or equal to the force change threshold , for the current second position Make adjustments: If the current second position Less than the maximum second position , current second position Adjust according to the following formula: in, represents the second conversion relationship; If the current second position Greater than or equal to the maximum second position , change the current second position Adjust to the second maximum position .

10. A magnetorheological polishing method with a variable removal function, based on the magnetorheological polishing device based on force sensor adjustment according to any one of claims 1 to 5, characterized in that: The following steps are involved: C1: Controlling the polishing wheel to process the test optical element with different polishing gaps to obtain the removal function; simultaneously, recording the force changes at each processing point through the force sensor during the processing, and obtaining a seventh conversion relationship between the removal function volume removal rate of each processing point and the force in the conversion relationship module; C2: using the processing program module to obtain the processing program according to the removal function, and importing the processing program into the magnetorheological processing module; C3: Setting a force change threshold and a force maximum value; combining the seventh conversion relationship, the force change threshold and the force maximum value, controlling the magnetorheological machining module to machine the optical element to be machined, and calculating the removal function of each machining point during the machining process to obtain a set of variable removal functions, thereby generating a new machining program; C4: Importing a new processing program into the magnetorheological processing module, and then performing secondary processing on the optical element to be processed.

11. The magnetorheological polishing method with variable removal function according to claim 10, characterized in that: Obtaining the seventh conversion relationship in step C1 includes the following steps: C11: Control the polishing wheel to process the test optical element with different polishing gaps, and record the corresponding force changes at each processing point through the force sensor, and obtain in the conversion relationship module: in, Represents the force Between the polishing gap The eighth conversion relationship; C12: Control the polishing wheel to process different positions of the test optical element with different polishing gaps, and calculate the removal function volume removal rate of each processing point, and obtain the following in the conversion relationship module: in, Represents the volume removal rate of the removal function With the polishing gap The ninth conversion relationship between; C13: In the conversion relationship module, the seventh conversion relationship is calculated based on the eighth conversion relationship and the ninth conversion relationship, that is: in, Represents the seventh conversion relationship.

12. The magnetorheological polishing method with variable removal function according to claim 11, characterized in that: In step C3, the magnetorheological processing module is controlled to move to the current processing position. When the current force measured by the force sensor Force change threshold For comparison: If the current force Less than the force change threshold , the change of the current removal function is not calculated; If the current force Greater than or equal to the force change threshold , calculate the change of the current removal function: If the current force Less than the maximum force , calculate the current processing point by the following formula The corresponding removal function , and then get the set of variable removal functions : in, Indicates the current processing point The corresponding removal function volume removal rate; If the current force Greater than or equal to the maximum force , the current processing point is obtained by the following formula The corresponding removal function , and then get the set of variable removal functions : in, Indicates maximum force The corresponding maximum removal function volume removal rate.

13. An actuator-regulated magnetorheological polishing method, based on the force sensor-regulated magnetorheological polishing device according to any one of claims 1 to 5, characterized in that: The following steps are involved: D1: Setting the force change threshold and the maximum value control of the actuator group; D2: Control the magnetorheological processing module to move to the current processing position When the current force measured by the force sensor is compared with the force change threshold: if the current force is less than the force change threshold, executing step D4; If the current force is greater than the force change threshold, executing step D3; D3: If the current position change of the polishing wheel is less than the maximum value, the output displacement of the actuator group is controlled to be the current position change, and the optical element to be processed is processed; if the current position change of the polishing wheel is greater than the maximum value, the output displacement of the actuator group is controlled to be the maximum value, and the optical element to be processed is processed; D4: controlling the magnetorheological processing module to move to the next processing position, and repeating steps D2 and D3 until the magnetorheological processing module is controlled to traverse all processing points on the optical element to be processed.

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