Magnetorheological processing device and method based on motor current regulation

Abstract

The present invention relates to the field of magnetorheological technology, and specifically to a magnetorheological processing device and method based on motor current regulation. The device includes a polishing component, a moving component and a control unit. When the polishing module polishes the polishing element, the first instantaneous current corresponding to the processing position corresponding to different supply parameters is collected, and the corresponding relationship between the supply parameters and the ideal motor current is calculated. Then, based on this, the second instantaneous current data is judged, and it is decided whether to adjust the supply parameters according to the judgment result, so as to adjust the supply parameters in real time by using the moving component; or the removal function during the first processing is collected to obtain a variable removal function set, and the variable removal function set is used as the input for the second processing; the processing process does not require the calibration step of parameters such as gravity compensation, and the accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement result is more accurate, which reduces the equipment cost.

Description

Technical Field

[0001] The present invention relates to the field of magnetorheological technology, and in particular to a magnetorheological processing device and method based on motor current regulation. Background Art

[0002] Magnetorheological finishing (MRF) is an advanced optical manufacturing technology that has developed in recent years. It offers 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 machining centers primarily integrate polishing modules onto CNC machine tools. However, CNC machine tools have limitations (such as low degrees of freedom, large footprint, and high cost) that limit the deviation of aspheric surfaces and hinder precise position control along the surface normal. 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 polishing module is integrated into the industrial robot, theoretically, high-precision processing of large-aperture complex curved optical components can be achieved. However, due to the influence of factors such as processing, assembly, load, trajectory planning, and reduction ratio, the robot end execution accuracy is low, and the polishing gap changes greatly during the processing. At the same time, magnetorheological polishing technology is an optical processing technology with high certainty 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 changes 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 cannot meet the requirements of magnetorheological polishing technology for polishing gap changes during high-precision polishing.

[0003] Force-position control is currently gaining popularity as a new approach to robotic constant-force controlled polishing. A common application involves placing a force sensor between the machining tool and the robot. The force sensor is first calibrated with gravity to ensure measurement accuracy. The position error is calculated by measuring force changes. This position error is then compensated for using the robot itself or other motion compensation mechanisms to achieve constant force control. Efficient machining of large-aperture optical components requires magnetorheological (MR) machining equipment with large polishing wheels. These MR machining modules typically weigh hundreds of kilograms. However, for these MR machining modules, the force variation caused by the robot's position error is only tens of Newtons. High-precision machining requires maintaining a constant force of a few Newtons or even a fraction of a Newton. This requires measurement equipment such as force sensors to achieve an absolute accuracy of one part per ten thousand. Furthermore, the force sensor must be capable of varying speed and position. Force sensors that meet these requirements are often extremely expensive, significantly increasing the cost of the equipment. Summary of the Invention

[0004] In view of this, the present invention aims to provide a magnetorheological processing device and method based on motor current regulation, which adjusts the relevant supply parameters of the nozzle and supply system in the polishing assembly by sensing the motor current, thereby completing the regulation of the magnetorheological processing process, solving the problem that the existing technology requires the use of high-precision force sensors for data collection for the regulation of the polishing wheel, and the high cost of high-precision force sensors.

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

[0006] A magnetorheological processing device based on motor current regulation, the device comprising:

[0007] The polishing assembly includes a drive motor and a polishing module, wherein the drive motor is used to drive the polishing module to move;

[0008] A moving assembly, rigidly connected to the polishing assembly, for driving the polishing assembly to move to the position of the element to be polished, and for adjusting the polishing gap between the polishing module and the element to be polished and the working position of the polishing assembly;

[0009] A control unit controls the polishing module to perform fixed-point processing on the polishing element with different supply parameters, collects the instantaneous current of the drive motor in real time, and adjusts the supply parameters according to the instantaneous current; or records the removal function during processing to obtain a variable removal function set, which is used as the output of the next processing to perform secondary processing on the polishing element;

[0010] The supply parameters include the nozzle position of the nozzle in the polishing module and the supply height of the supply system.

[0011] Furthermore, in the control unit: a correspondence between the supply parameter and the set ideal motor current is calculated based on the first polishing data, the first polishing data including first instantaneous current data of the driving motor under the set supply parameter; and second instantaneous current data is collected in real time, and the second instantaneous current data is compared with the ideal motor current corresponding to the current supply parameter in the correspondence relationship. If the difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the current supply parameter is adjusted so that the difference between the second instantaneous current data collected after the supply parameter adjustment and the ideal motor current is within the preset error range.

[0012] The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module to polish the component to be polished at a constant speed.

[0013] Furthermore, the polishing module includes:

[0014] A magnetorheological mounting frame is connected to the moving assembly; the driving motor is arranged on the magnetorheological mounting frame;

[0015] The polishing wheel is arranged on the magnetorheological mounting frame, and the driving motor drives the polishing wheel to rotate;

[0016] a magnet disposed on the magnetorheological mounting frame and close to the working point of the polishing wheel;

[0017] A magnetorheological medium is connected to the polishing wheel. The magnetorheological medium is driven by the polishing wheel to enter the magnetic field working area of ​​the magnet to form a magnetorheological ribbon. The magnetorheological ribbon size parameters change with the polishing gap and the magnetic field strength generated by the magnet, and is used to polish the component to be polished.

[0018] The nozzle is mounted on the magnetorheological mounting frame via a nozzle mounting seat to provide magnetorheological medium to the polishing wheel, and the nozzle mounting seat adjusts the nozzle position;

[0019] The supply system is connected to the nozzle and delivers the magnetorheological medium to the nozzle.

[0020] Furthermore, the supply system includes a liquid pump, a supply mounting bracket, a supply motor and a ball screw; wherein, the supply motor and the ball screw are arranged on the supply mounting bracket, so that the supply motor drives the ball screw to rotate; the liquid pump is arranged on the ball screw, so that the ball screw drives the liquid pump to move, thereby changing the supply height; the liquid pump transports magnetorheological fluid to the nozzle through a pipeline.

[0021] 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 nozzle position.

[0022] A magnetorheological machining method based on motor current regulation of a nozzle, according to the magnetorheological machining device based on motor current regulation provided by the present invention, the method comprises the following steps:

[0023] The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element;

[0024] The control unit calculates a correspondence between the nozzle position and a set ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected at different set nozzle positions; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current nozzle position in the correspondence. If a difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the control unit controls the polishing module to adjust the current nozzle position or nozzle aperture so that the difference between the adjusted second instantaneous current data and the ideal motor current is within the preset error range.

[0025] The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module to polish the component to be polished at a constant speed.

[0026] Furthermore, if the current nozzle position NL i The adjustment margin to or beyond the upper threshold of the preset error range is recorded as +ΔNL max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude;

[0027] By the current nozzle position NL i The adjustment margin to or beyond the lower limit of the preset error range is recorded as -ΔNL max , the corresponding current output value of the drive motor is A0-ΔA max ;

[0028] Control the polishing module to the current nozzle position NL iAdjustments include:

[0029] If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to control the polishing module to the current nozzle position NL i Make adjustments;

[0030] If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then the polishing module is controlled according to the corresponding relationship F na For the current nozzle position NL i Adjust according to the following formula:

[0031] ;

[0032] If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current nozzle position NL i Directly adjust to NL0±ΔNL max NL0 represents the initial nozzle position, so that the second instantaneous current data A corresponding to the adjusted nozzle position is i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

[0033] A magnetorheological machining method based on motor current regulation supply height, according to the magnetorheological machining device based on motor current regulation provided by the present invention, the method comprises the following steps:

[0034] The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element;

[0035] The control unit calculates a correspondence between the supply height and a set ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected at different set supply heights; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current supply height in the correspondence. If a difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the control unit controls the polishing module to adjust the current supply height so that the difference between the second instantaneous current data collected after adjustment and the ideal motor current is within the preset error range.

[0036] The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module to polish the component to be polished at a constant speed.

[0037] Furthermore, if the current supply height SP i The adjustment range to the upper threshold of the preset error range is recorded as +ΔSP max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude;

[0038] By the current supply height SP i The adjustment range to the lower limit threshold of the preset error range is recorded as -ΔSP max , the corresponding current output value of the drive motor is A0-ΔA max ;

[0039] Control the polishing module to the current supply height SP i Adjustments include:

[0040] If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to control the polishing module to the current supply height SP i Make adjustments;

[0041] If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then the control polishing module combines the corresponding relationship F pa Current supply height SP i Adjust according to the following formula:

[0042] ;

[0043] If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current supply height SP i Directly adjust to SP0±ΔSP max , SP0 represents the initially set supply height, so that the second instantaneous current data A corresponding to the adjusted supply height i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

[0044] A magnetorheological machining method based on motor current regulation to remove function variation, according to the magnetorheological machining device based on motor current regulation provided by the present invention, the method comprises the following steps:

[0045] The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element;

[0046] The control unit calculates a correspondence between a removal function and an ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected under different set removal functions; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current removal function in the correspondence. If a difference between the second instantaneous current data and the ideal motor current corresponding to the current removal function exceeds a preset error range, the control unit records the motor current corresponding to the current removal function. After completing a single machining operation, the control unit calculates the removal function for each machining point based on the recorded motor current to generate a set of removal functions.

[0047] The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module at a constant speed to polish the polishing component;

[0048] The moving component drives the polishing component to move back to the original processing position of the element to be polished and contact the element to be polished, and combines with the variable removal function set to re-process the element to be polished. The processing amount of each processing point on the element to be polished is determined by the variable removal function set, ensuring the accuracy of material removal using the variable removal function in the actual processing process.

[0049] Furthermore, the upper and lower thresholds in the preset removal function variation range are set to ±RF max , the corresponding current output value of the drive motor is A0±ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude;

[0050] If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to change the current data A of the processing point i The corresponding removal function;

[0051] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then we need to follow the corresponding relationship F ra Calculate the current removal function RF i :

[0052] ;

[0053] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current removal function RF i ±|RF max |,|RF max | represents the set maximum removal function;

[0054] After the processing is completed, based on the current data A recorded at each processing point i Calculate the corresponding processing point (X i ,Y i ) corresponding to the removal function RF i , get the set of variable removal functions {RF i}, in the next processing, the function set {RF i}As the input of processing parameters, it can achieve accurate material removal and improve the certainty of processing.

[0055] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0056] The present invention utilizes the relationship between the polishing module and the motor current. When the polishing module polishes the element to be polished, it collects different supply parameters and their corresponding first instantaneous current data and obtains their respective corresponding relationships. Then, the second instantaneous current data is judged based on these corresponding relationships. Based on the judgment result, it is decided whether to adjust the supply parameters, or to collect the removal function after each adjustment to generate a variable removal function set, and then combine the variable removal function set for secondary processing. This process does not require calibration steps for parameters such as gravity compensation, and will not be affected by the weight of the magnetorheological processing module of the robotic magnetorheological processing equipment, the equipment's own operating accuracy, operating speed, posture, inertia, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement results are more accurate, and there is no need to add high-precision force sensors and other equipment, thereby reducing equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] 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:

[0058] Figure 1 A schematic diagram of a magnetorheological processing device based on motor current regulation according to an embodiment of the present invention at one viewing angle;

[0059] Figure 2 A schematic diagram of a magnetorheological machining device based on motor current regulation according to an embodiment of the present invention from another perspective;

[0060] Figure 3 A schematic diagram of the structure of the supply system according to an embodiment of the present invention;

[0061] Figure 4 A schematic structural diagram of a liquid pump according to an embodiment of the present invention;

[0062] Figure 5 This is a schematic structural diagram of the nozzle mounting seat described in an embodiment of the present invention.

[0063] Description of reference numerals:

[0064] 1. Polishing platform; 2. Component to be polished; 3. Polishing module; 4. Drive motor; 5. Control unit; 6. Moving assembly; 7. Magnetorheological mounting frame; 8. Polishing wheel; 9. Transmission belt; 10. Magnet; 11. Nozzle; 12. Supply system; 13. Nozzle mounting seat; 14. Liquid pump; 15. Supply mounting bracket; 16. Supply motor; 17. Ball screw; 18. Mounting plate; 19. Slide rail; 20. Liquid pump body; 21. Cooling chamber; 22. Magnetorheological fluid storage chamber; 23. Cooling water inlet; 24. Magnetorheological fluid inlet; 25. Cooling water outlet; 26. Magnetorheological fluid outlet; 27. Nozzle support frame; 28. Nozzle adjustment motor; 29. ​​Fixed frame; 30. Push rod; 31. Slider; 32. Arc slide rail. DETAILED DESCRIPTION

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0070] like Figures 1 to 5 As shown, the magnetorheological processing device based on motor current regulation described in the embodiment of the present invention includes a polishing platform 1, a polishing assembly, a control unit 5, and a moving assembly 6. The polishing platform 1 carries the component 2 to be polished. The polishing assembly includes a polishing module 3 and a drive motor 4. The polishing module 3 is used to process the component 2 to be polished, and the drive motor 4 is used to drive the polishing module 3 to move. The moving assembly 6 is rigidly connected to the polishing assembly and is used to drive the polishing assembly to the position of the component 2 to be polished. The control unit 5 controls the polishing module 3 to process the component 2 to be polished with different supply parameters, and collects the instantaneous current of the drive motor 4 in real time and adjusts the supply parameters based on the instantaneous current. Alternatively, the control unit 5 records the removal function during processing to obtain a variable removal function set, which is used as the output of the next processing to perform secondary processing on the component to be polished. The supply parameters include the nozzle position of the nozzle 11 in the polishing module and the supply height of the supply system 12.

[0071] In this embodiment, the polishing platform 1 refers to a working platform for experiments, on which the element to be polished 2 and other polishing parts are placed, such as the magnetorheological medium required for polishing, the test optical element for test processing, and the supporting tooling for the element to be polished 2, etc., among which the test optical element and the element to be polished 2 are parts that need to be subjected to magnetorheological polishing processing.

[0072] The polishing module 3 includes a magnetorheological mounting frame 7, a polishing wheel 8, a magnet 10, a magnetorheological medium, a nozzle 11 and a supply system 12. The magnetorheological mounting frame 7 is rigidly connected to the moving component 6, and the drive motor 4 is arranged on the magnetorheological mounting frame 7; the polishing wheel 8 is arranged on the magnetorheological mounting frame 7, and the output end of the drive motor 4 is connected to the bearing of the polishing wheel 8 through the transmission belt 9, so that the drive motor 4 controls the polishing wheel 8 to rotate. In the embodiment of the present invention, the way in which the drive motor 4 drives the polishing wheel 8 to rotate 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 magnet 10 is installed on the magnetorheological mounting frame 7 and close to the working point of the polishing wheel 8 (in the embodiment of the present invention, the working point of the polishing wheel 8 is specified to be along The normal direction of the surface of the element 2 to be polished, the closest point between the polishing wheel 8 and the surface of the element 2 to be polished); the magnetorheological medium is connected to the polishing wheel 8, and the magnetorheological medium is used to enter the magnetic field working area of ​​the magnet 10 under the drive of the polishing wheel 8 to form a magnetorheological ribbon. The size parameters of the magnetorheological ribbon change with the polishing gap and the magnetic field strength generated by the magnet 10, and is used to polish the element 2 to be polished; the nozzle 11 is installed on the magnetorheological mounting frame 7 along the rotation direction of the polishing wheel 8 through the nozzle mounting seat 13. The nozzle mounting seat 13 adjusts the installation angle of the nozzle 11, thereby changing the position of the nozzle opening of the nozzle 11 (i.e., the nozzle position); the supply system 12 is connected to the nozzle 11 to deliver the magnetorheological medium to the nozzle 11.

[0073] In an embodiment of the present invention, the supply system 12 includes a liquid pump 14, a supply mounting bracket 15, a supply motor 16, and a ball screw 17. The supply motor 16 and the ball screw 17 are mounted on the supply mounting bracket 15, and the output end of the supply motor 16 is connected to one end of the ball screw 17, so that the supply motor 16 drives the ball screw 17 to rotate. The liquid pump 14 is mounted on the ball screw 17, so that the ball screw 17 drives the liquid pump 14 to move, thereby changing the supply height. Specifically, the screw in the ball screw 17 is mounted on the supply mounting bracket 15 and connected to the output end of the supply motor 16. The liquid pump 14 is connected to the nut of the ball screw 17. The supply motor 16 drives the screw to rotate, and the nut cooperates with the screw to pull the liquid pump 14 along the screw direction, thereby changing the supply height. The liquid pump 14 delivers magnetorheological fluid to the nozzle 11 through a pipeline. In an embodiment of the present invention, in order to enable the liquid pump 14 to move smoothly along the direction of the ball screw 17 without offset, a slide rail 19 parallel to the ball screw 17 is installed on each side of the ball screw 17, and the liquid pump 14 is fixedly connected to the nut of the ball screw 17 and the sliders 31 on the two slide rails 19 through the mounting plate 18, so that the supply motor 16 drives the ball screw 17, and the two slide rails 19 of the ball screw 17 cooperate to pull the mounting plate 18, so that the mounting plate 18 and the liquid pump 14 on the mounting plate 18 can move smoothly.

[0074] In the embodiment of the present invention, the structure of the liquid pump 14 is as follows Figure 4 As shown, it includes a liquid pump body 20, a cooling chamber 21, and a magnetorheological fluid storage chamber 22. The liquid pump body 20 is used to supply magnetorheological fluid; the cooling chamber 21 is mainly used to store cooling water and cool the magnetorheological fluid; the magnetorheological fluid storage chamber 22 is mainly used to store magnetorheological fluid. When the liquid pump 14 is operating, cooling water enters the cooling chamber 21 from the cooling water inlet 23 to cool the magnetorheological fluid. The magnetorheological fluid then flows from the magnetorheological fluid inlet 24 through the magnetorheological fluid storage chamber 22 into the liquid pump body 20. After the cooling water cools the magnetorheological fluid in the cooling chamber 21, it is discharged from the cooling water outlet 25. The cooled magnetorheological fluid is output from the magnetorheological fluid outlet 26 and transported to the nozzle 11 through a pipeline. At this time, the outlet of the supply system 12 is the magnetorheological fluid outlet 26. Furthermore, the supply height of the supply system 12 is the vertical distance between the nozzle opening of the nozzle 11 and the magnetorheological fluid outlet 26. In the embodiment of the present invention, the liquid pump body 20 uses a DFLD vertical multi-stage pump manufactured by Shanghai Dongfang Pump Industry Co., Ltd.

[0075] The structure of the nozzle mounting seat 13 is as follows Figure 5 As shown. Figure 5 (a) shows a schematic structural diagram of the nozzle 11 when it is installed on the nozzle mounting seat 13. Figure 5(b) in the figure shows a schematic diagram of the structure when the nozzle 11 is not installed on the nozzle mounting base 13. In the nozzle mounting base 13, the fixing frame 29 is an L-shaped structure and is fixed to the magnetorheological mounting base 7. A circular arc slide 32 is arranged on the inner side wall of the fixing frame 29. The nozzle adjustment motor 28 is mounted on the magnetorheological mounting base 7. One end of the push rod 30 passes through the bottom edge of the fixing frame 29 and is connected to the output end of the nozzle adjustment motor 28. The nozzle adjustment motor 28 pushes the push rod 30, which in turn pushes the slider 31 on the circular arc slide 32 to move along the circular arc slide 32. One end of the nozzle support frame 27 is fixed to the slider 31, and the nozzle 11 is mounted on the other end of the nozzle support frame 27. When controlling the nozzle mounting base 13 to adjust the position of the nozzle 11, the nozzle adjustment motor 28 outputs a displacement, causing the push rod 30 to push the slider 31, which in turn causes the nozzle support frame 27 to move the nozzle 11, thereby completing the nozzle position adjustment.

[0076] The driving motor 4, the moving assembly 6, the supply system 12 and the nozzle mounting seat 13 are respectively connected to the control unit 5 to form their own communication lines, so that the control unit 5 receives and sends signals through the corresponding communication lines. Specifically, the control unit 5 is connected to the supply system 12 through a line for communication. During operation, the control unit 5 gives a control instruction to the supply motor 16, and the supply motor 16 drives the ball screw 17 to rotate. The rotating ball screw 17 drives the mounting plate 18 to move up and down, thereby changing the up and down position of the liquid pump 14, thereby changing the first position of the supply system 12; the control unit 5 controls the nozzle adjustment motor 28, thereby changing the position of the nozzle support frame 27, and the nozzle support frame 27 moves along the arc slide rail 32, thereby changing the nozzle position of the nozzle 11. Since a strong magnetic area is generated around the polishing wheel 8 during the polishing operation, the communication line avoids the strong magnetic area to prevent the wires from being adsorbed on the polishing module 3 and affecting normal operation.

[0077] The moving component 6 can be a robotic arm or other robot with posture adjustment function; optionally, the moving component 6 is a six-axis robotic arm, the driving motor 4 and the robotic arm are rigidly connected by metal hardware, and the robotic arm drives the polishing component to complete the processing of the entire component 2 to be polished.

[0078] When the supply parameters in polishing module 3 change, the shear force between the polished component 2 and the magnetorheological medium in polishing module 3 changes. To maintain a constant polishing speed, the current of drive motor 4 will eventually change accordingly. The change in supply parameters is calculated by measuring the change in the current of drive motor 4.

[0079] In this embodiment, the control unit 5 is configured to obtain first polishing data based on the current of the drive motor 4 under different supply parameters when the drive motor 4 drives the polishing module 3 or the test optical element for fixed-point polishing, and calculate the corresponding relationship between the supply parameters and the ideal motor current based on the first polishing data. The first polishing data includes first instantaneous current data of the drive motor 4 under different supply parameters, and the different supply parameters can be pre-set.

[0080] The first polishing data can be collected multiple times, and finally the error between multiple sets of first polishing data can be reduced by numerical calculation methods such as taking the mean or variance, and then the relationship between the ideal motor current and the supply parameter is calculated based on the first polishing data.

[0081] In this embodiment, the control unit 5 calculates the correlation between the first instantaneous current data and its corresponding supply parameter to determine the correspondence between different supply parameters and the set ideal motor current. Using this as a reference, when polishing the component 2 to be polished, the control unit 5 compares the second instantaneous current data corresponding to different polishing areas of the component 2 to see if the difference between the second instantaneous current data and the ideal motor current is within a preset error range. If not, the supply parameter is adjusted to ensure that the current second instantaneous current data is the same as, or within the same preset error range as, the ideal motor current corresponding to the current supply parameter. This approach enables real-time adjustment of the supply parameter based on the correspondence between the supply parameter and the instantaneous current.

[0082] By utilizing the relationship between the polishing module 3 and the motor current, when polishing is performed using the polishing module 3, different supply parameters and their corresponding first instantaneous current data are collected, and then the corresponding relationship between the supply parameters and the ideal motor current is calculated through the collected supply parameters and the first instantaneous current data. Thereafter, the second instantaneous current data is judged by this relationship, and it is decided whether to adjust the supply parameters of the polishing element 2 based on the judgment result. This process does not require calibration steps for parameters such as gravity compensation, and will not be affected by the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the equipment's own operating accuracy, operating speed, posture, inertia and other factors. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement results are more accurate, and there is no need to add high-precision force sensors and other equipment, thereby reducing equipment costs.

[0083] The specific polishing principle is as follows: when the polishing wheel is polishing, the magnetorheological medium is affected by the magnetic field change, changing from liquid to solid-state, forming a Bingham fluid. As the polishing wheel rotates, the Bingham fluid applies shear force to the outer surface of the element to be polished 2, thereby polishing the element to be polished 2. Different supply parameters correspond to different shear forces, and therefore, different supply parameters achieve different polishing effects. When the supply parameters change, the thickness of the magnetorheological ribbon of the magnetorheological medium placed in the polishing area changes, causing the shear force between the element to be polished 2 and the magnetorheological ribbon to change. In order to maintain a constant speed of the polishing wheel, the current of the drive motor 4 will eventually change accordingly. The corresponding relationship can be expressed as follows:

[0084] ;

[0085] Where n represents the polishing wheel speed, k represents the proportional coefficient, U represents the voltage of drive motor 4, F represents the force (i.e., shear force) acting on drive motor 4, r represents the torque (i.e., the lateral distance from the lowest point of the polishing wheel to the motor), and I represents the current of drive motor 4. By measuring the change in the current of drive motor 4, the change in the thickness of the magnetorheological ribbon in the polishing area is obtained, and the change in the current supply parameter is calculated. Finally, the polishing module 3 realizes real-time control of the supply parameter change.

[0086] Based on the magnetorheological processing device based on motor current regulation described in the embodiment of the present invention, the embodiment of the present invention also provides a magnetorheological processing method based on motor current regulation, including a magnetorheological processing method based on motor current regulation of the nozzle, and a magnetorheological processing method based on motor current regulation of the supply height.

[0087] Example 1: A magnetorheological processing method based on motor current regulation nozzle, according to the magnetorheological processing device based on motor current regulation provided by the embodiment of the present invention, combined with Figures 1 to 5 The method comprises the following steps:

[0088] The moving assembly 6 drives the polishing assembly to move to the location of the test optical element, and makes the polishing module 3 contact with the test optical element;

[0089] The control unit 5 calculates a correspondence between the nozzle position and the ideal motor current based on the first polishing data, the first polishing data including real-time current data of the drive motor 4 collected at different set nozzle positions; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current nozzle position in the correspondence. If the difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the polishing module 3 is controlled to adjust the current nozzle position so that the difference between the second instantaneous current data collected after adjustment and the ideal motor current is within the preset error range.

[0090] The second instantaneous current data is the current data of the driving motor 4 collected in real time by the control unit 5 when the driving motor 4 drives the polishing module 3 at a constant speed to polish the component to be polished.

[0091] In this embodiment, it is necessary to first obtain the correspondence between the ideal motor current and the nozzle position. The moving component 6 drives the polishing module 3 to move to the position of the test optical element and contacts the test optical element. In this process, the contact between the test optical element and the polishing module 3 means that the polishing wheel contacts the outer surface of the test optical element through the magnetorheological medium, and the part where the polishing module 3 contacts the test optical element is recorded as the first processing point. During the measurement of the same set of first polishing data, the first processing point remains unchanged. Optionally, when measuring multiple sets of first polishing data, different first processing points can be selected on the test optical element to facilitate improving the accuracy of the correspondence between the ideal motor current and the nozzle position.

[0092] During the process of polishing the test optical element by the polishing module 3, the control unit 5 controls the polishing module 3 to set different nozzle positions, collects the first instantaneous current data corresponding to different nozzle positions, maps and stores multiple sets of first instantaneous current data with the corresponding nozzle positions, and obtains the first polishing data. The control unit 5 calculates the correspondence between the nozzle position and the ideal motor current based on the first polishing data.

[0093] After obtaining the correspondence between the ideal motor current and the nozzle position, the nozzle position of the polishing area of ​​the polishing element 2 can be adjusted according to this correspondence. After the adjustment, the second instantaneous current data corresponding to the current nozzle position of the polishing element 2 is placed within the same preset error range as the ideal motor current.

[0094] By utilizing the relationship between the polishing module 3 and the motor current, when the polishing module 3 polishes the polishing element 2, different nozzle positions and the corresponding first instantaneous current data are collected, and then the corresponding relationship between the nozzle position and the ideal motor current is calculated through the collected nozzle position and the first instantaneous current data. Then, the second instantaneous current data is judged by this relationship, and it is decided whether to adjust the nozzle position of the polishing element 2 according to the judgment result, so that the nozzle position is adjusted in real time using the polishing module 3. This process does not require calibration steps of parameters such as gravity compensation, and will not be affected by the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the equipment's own operating accuracy, operating speed, posture, inertia and other factors. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement results are more accurate, and there is no need to add high-precision force sensors and other equipment, thereby reducing equipment costs.

[0095] In some embodiments, the correspondence between the nozzle position and the ideal motor current is a function curve relationship, and the function curve relationship is fitted according to the discrete values ​​of the nozzle position NL and the first instantaneous current data A to obtain the correspondence relationship F na for:

[0096] .

[0097] In this embodiment, a plurality of nozzle positions NL correspond to a plurality of first instantaneous current data A. Both the nozzle positions NL and the first instantaneous current data A are discrete values. Therefore, the discrete values ​​need to be fitted.

[0098] Fitting process: The discrete data is imported into Matlab software, and the data is fitted using the polyfit command in Matlab to determine the correspondence between the nozzle position and the ideal motor current parameters. The Polyfit command is a basic, general command in Matlab software. The resulting correspondence between the nozzle position and the ideal motor current is a functional relationship.

[0099] In this way, the corresponding relationship between the ideal motor current and the nozzle position can be more intuitively seen. Based on this, multiple components 2 to be polished under the same polishing conditions can be polished.

[0100] In some embodiments, if the sampling period for collecting the second instantaneous current data is recorded as t1, the shortest time required for the nozzle position to complete the set maximum adjustment amount is recorded as t2, and the shortest switching time between two adjacent trajectory points to be processed on the component to be polished 2 is recorded as t3;

[0101] Methods include:

[0102] Determine whether the relationship between t1, t2, and t3 satisfies the formula:

[0103] ;

[0104] If not, the sampling frequency of the control unit for collecting the second instantaneous current data is adjusted until the above formula is satisfied, and the sampling frequency is 1 / t1.

[0105] In this embodiment, the above formula gives the corresponding relationship between the three time elements, namely: within a single sampling cycle, the moving component 6 can adjust the polishing module 3 so that it moves to the polishing gap corresponding to the ideal motor current, and then performs the next sampling, so as to avoid the sampling cycle being too long resulting in the sampling frequency being too slow, so that the sampling frequency and the adjustment speed of the nozzle position are not matched, and the adjustment is not timely, resulting in the inability to know the current state of the second instantaneous current data, affecting the automatic compensation function of the polishing gap.

[0106] In some embodiments, the maximum nozzle position adjustment amount is the adjustment amplitude corresponding to the adjustment from the set ideal nozzle position to the upper threshold or lower threshold of the preset error range, which is recorded as ΔNL max ;

[0107] t2=ΔNL max / V1,t3=ΔL / V max , where V1 is the maximum adjustment speed of the nozzle position, V max is the maximum moving speed of the moving assembly 6, and ΔL represents the distance between two adjacent track points to be processed on the component to be polished 2.

[0108] In some embodiments, the method further comprises:

[0109] When the moving component 6 drives the polishing module to move from the first track point to the second track point, the second instantaneous current data collected by the control unit during the movement is filtered, and the filtered second instantaneous current data is compared with the ideal motor current under the current polishing gap;

[0110] If the number of second instantaneous current data collected by the control unit during the movement is recorded as a, then a satisfies the following formula:

[0111] .

[0112] In this embodiment, this method can avoid the influence of random signals and mutation signals generated during the second instantaneous current data on the measurement results of the second instantaneous current data, making the adjustment of the polishing gap more accurate.

[0113] In some embodiments, if the current nozzle position NL i The adjustment range to the upper limit threshold of the preset error range is recorded as +ΔNL max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude;

[0114] By the current nozzle position NL i The adjustment range to the lower limit threshold of the preset error range is recorded as -ΔNL max , the corresponding current output value of the drive motor is A0-ΔA max ;

[0115] Control polishing module 3 to the current nozzle position NL i Adjustments include:

[0116] If the current second instantaneous current data A iDoes not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to control the polishing module 3 to the current nozzle position NL i Make adjustments;

[0117] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then control the polishing module 3 in combination with the corresponding relationship F na For the current nozzle position NL i Adjust according to the following formula:

[0118] ;

[0119] If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current nozzle position NL i Directly adjust to NL0±ΔNL max NL0 represents the initial nozzle position, so that the second instantaneous current data A corresponding to the adjusted nozzle position is i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

[0120] By adjusting the nozzle change, the current A of the next processing point i+1 Within the allowable range of variation, the magnetorheological high-precision processing requirements are met.

[0121] Example 2: A magnetorheological processing method based on motor current regulation supply height, according to the magnetorheological processing device based on motor current regulation provided by the embodiment of the present invention, combined with Figures 1 to 5 The method comprises the following steps:

[0122] The moving assembly 6 drives the polishing assembly to move to the location of the test optical element, and makes the polishing module 3 contact with the test optical element;

[0123] The control unit 5 calculates a correspondence between the supply height and a set ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor 4 collected at the set supply height; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the supply height in the correspondence. If the difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the polishing module 3 controls the difference between the second instantaneous current data collected after adjusting the supply height and the ideal motor current to be within the preset error range.

[0124] The second instantaneous current data is the current data of the driving motor 4 collected in real time by the control unit 5 when the driving motor 4 drives the polishing module 3 at a constant speed to polish the component to be polished.

[0125] In this embodiment, it is necessary to first obtain the correspondence between the ideal motor current and the supply height. The moving component 6 drives the polishing module 3 to move to the position of the test optical element and contact the test optical element. In this process, the contact between the test optical element and the polishing module 3 means that the polishing wheel contacts the outer surface of the test optical element through the magnetorheological medium, and the part where the polishing module 3 contacts the test optical element is recorded as the first processing point. During the measurement of the same set of first polishing data, the first processing point remains unchanged. Optionally, when measuring multiple sets of first polishing data, different first processing points can be selected on the test optical element to facilitate improving the accuracy of the correspondence between the ideal motor current and the supply height.

[0126] During the process of polishing the test optical element by the polishing module 3, the control unit 5 controls the polishing module 3 to set different supply heights, collects the first instantaneous current data corresponding to different supply heights, maps and stores multiple sets of first instantaneous current data with the corresponding supply heights, and obtains the first polishing data. The control unit 5 calculates the correspondence between the supply height and the ideal motor current based on the first polishing data.

[0127] After obtaining the correspondence between the ideal motor current and the supply height, the supply height of the polishing area of ​​the polishing element 2 to be polished can be adjusted according to the correspondence, so that the second instantaneous current data corresponding to the adjusted current supply height is placed in the same preset error range as the ideal motor current. This process does not require calibration steps for parameters such as gravity compensation, and will not be affected by the weight of the magnetorheological processing module of the robotic magnetorheological processing equipment, the equipment's own operating accuracy, operating speed, posture, inertia and other factors. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement results are more accurate, and there is no need to add high-precision force sensors and other equipment, thereby reducing equipment costs.

[0128] In some embodiments, the corresponding relationship between the supply height SP and the ideal motor current is a function curve relationship, and the function curve relationship is fitted according to the discrete values ​​of the supply height SP and the first instantaneous current data A to obtain the corresponding relationship F pa for:

[0129] .

[0130] In this embodiment, a plurality of supply heights SP correspond to a plurality of first instantaneous current data A. Both the supply heights SP and the first instantaneous current data A are discrete values. Therefore, the discrete values ​​need to be fitted.

[0131] Fitting process: The discrete data is imported into Matlab software and fitted using the polyfit command in Matlab to determine the relationship between the supply height and the ideal motor current parameters. Polyfit is a basic, general command in Matlab. The resulting relationship between the supply height and the ideal motor current is a functional relationship.

[0132] In this way, the corresponding relationship between the ideal motor current and the supply height can be more intuitively seen. Based on this, multiple components 2 to be polished under the same polishing conditions can be polished.

[0133] In some embodiments, if the sampling period for collecting the second instantaneous current data is recorded as t1, the shortest time required for the supply system to complete the set maximum adjustment amount of the supply position is recorded as t2, and the shortest switching time between two adjacent trajectory points to be processed on the component to be polished 2 is recorded as t3;

[0134] Methods include:

[0135] Determine whether the relationship between t1, t2, and t3 satisfies the formula:

[0136] ;

[0137] If not, the sampling frequency of the control unit for collecting the second instantaneous current data is adjusted until the above formula is satisfied and the sampling frequency is 1 / t1;

[0138] In this embodiment, the above formula gives the corresponding relationship between the three time elements, namely: within a single sampling cycle, the moving component 6 can adjust the polishing module 3 so that it moves to the polishing gap corresponding to the ideal motor current before performing the next sampling, thereby avoiding the sampling cycle being too long, resulting in the sampling frequency being too slow, causing the sampling frequency to not match the adjustment speed of the supply position or the adjustment to be untimely, resulting in the inability to know the current state of the second instantaneous current data, and affecting the automatic compensation function of the polishing gap.

[0139] In some embodiments, the maximum adjustment amount of the supply position is the adjustment amplitude corresponding to the upper threshold or lower threshold of the preset error range from the ideal supply position, which is recorded as ΔSP max ;

[0140] t2=ΔSP max / V1,t3=ΔL / V max , where V1 is the maximum position adjustment speed of the supply system, V max is the maximum moving speed of the moving assembly 6, and ΔL represents the distance between two adjacent track points to be processed on the component to be polished 2.

[0141] In some embodiments, the method further comprises:

[0142] When the moving component 6 drives the polishing module to move from the first track point to the second track point, the second instantaneous current data collected by the control unit during the movement is filtered, and the filtered second instantaneous current data is compared with the ideal motor current under the current polishing gap;

[0143] If the number of second instantaneous current data collected by the control unit during the movement is recorded as a, then a satisfies the following formula:

[0144] .

[0145] In this embodiment, this method can avoid the influence of random signals and mutation signals generated during the second instantaneous current data measurement on the measurement result of the second instantaneous current data, thereby making the adjustment of the polishing gap more accurate.

[0146] In some embodiments, if the current supply height SP i The adjustment range to the upper threshold of the preset error range is recorded as +ΔSP max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment range; the current supply height SP i The adjustment range to the lower limit threshold of the preset error range is recorded as -ΔSP max , the corresponding current output value of the drive motor 4 is A0-ΔA max ;

[0147] Control polishing module 3 to supply current height SP i Adjustments include:

[0148] If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A′′ ], there is no need to supply the current height SP i Make adjustments;

[0149] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then control the polishing module 3 in combination with the corresponding relationship F pa Current supply height SP i Adjust according to the following formula:

[0150] ;

[0151] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, current supply height SP i Directly adjust to SP0±ΔSP max , SP0 represents the initially set supply height, so that the second instantaneous current data A corresponding to the adjusted supply height i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

[0152] Based on the supply height SP i The change of the current A at the next processing point is regulated. i+1 Within the allowable range of variation, the magnetorheological high-precision processing requirements are met.

[0153] Example 3: A magnetorheological machining method based on motor current regulation to remove function changes, according to the magnetorheological machining device based on motor current regulation provided by the embodiment of the present invention, combined with Figures 1 to 5 The method comprises the following steps:

[0154] The moving assembly 6 drives the polishing assembly to move to the location of the test optical element, and makes the polishing module 3 contact with the test optical element;

[0155] The control unit 5 calculates a correspondence between the removal function and the ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor 4 collected under different set removal functions; and collects second instantaneous current data in real time. The control unit 5 compares the second instantaneous current data with the ideal motor current corresponding to the current removal function in the correspondence. If the difference between the second instantaneous current data exceeds a preset error range, the control unit 5 records the motor current corresponding to the current removal function. After completing a single machining operation, the control unit 5 solves the removal function for each machining point based on the recorded motor current to generate a set of removal functions.

[0156] The second instantaneous current data is the current data of the driving motor 4 collected in real time by the control unit 5 when the driving motor 4 drives the polishing module 3 at a constant speed to polish the component 2 to be polished;

[0157] The moving component 6 drives the polishing component to move back to the original processing position of the element to be polished 2 and contact the element to be polished 2, and combines the variable removal function set to re-process the element to be polished 2. The processing amount of each processing point on the element to be polished 2 is determined by the variable removal function set, ensuring the accuracy of material removal using the variable removal function in the actual processing process.

[0158] In this embodiment, it is necessary to first obtain the correspondence between the ideal motor current and the removal function. The moving component 6 drives the polishing module 3 to move to the location of the test optical element and contact the test optical element. In this process, the contact between the test optical element and the polishing module 3 means that the polishing wheel contacts the outer surface of the test optical element through the magnetorheological medium, and the portion where the polishing module 3 contacts the test optical element is recorded as the first processing point. During the measurement of the same set of first polishing data, the first processing point remains unchanged. Optionally, when measuring multiple sets of first polishing data, different first processing points can be selected on the test optical element to facilitate improving the accuracy of the correspondence between the ideal motor current and the removal function.

[0159] During the process of polishing the test optical element by the polishing module 3, the control unit 5 controls the moving component 6 to set different polishing gaps, collects the first instantaneous current data corresponding to different polishing gaps, maps and stores multiple groups of first instantaneous current data with the corresponding removal functions, and obtains the first polishing data. The control unit 5 calculates the correspondence between the removal function and the ideal motor current based on the first polishing data.

[0160] After obtaining the correspondence between the ideal motor current and the removal function, the polishing area of ​​the polishing element 2 to be polished can be processed according to the correspondence. After completing the first processing, the motor current corresponding to each processing point is recorded, and the corresponding removal function is solved to obtain a set of variation of the removal function. After the second processing, the variation of the removal function set is used as the processing parameter input to generate a processing control program to complete the second processing. This process does not require the calibration step of parameters such as gravity compensation, and is not affected by the weight of the magnetorheological processing module of the robotic magnetorheological processing equipment, the equipment's own operating accuracy, operating speed, posture, inertia, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data. The measurement results are more accurate, and there is no need to add equipment such as high-precision force sensors, which reduces equipment costs.

[0161] In some embodiments, the corresponding relationship between the removal function and the ideal motor current is a function curve relationship, and the function curve relationship is obtained by fitting the discrete values ​​of the removal function RF and the first instantaneous current data A to obtain the corresponding relationship F ra for:

[0162] .

[0163] In this embodiment, the removal function RF and the first instantaneous current data A are both discrete values, and therefore, the discrete values ​​need to be fitted.

[0164] Fitting process: The discrete data was imported into Matlab software and fitted using the polyfit command in Matlab to determine the relationship between the polishing gap and the ideal motor current parameters. The Polyfit command is a basic, general command in Matlab. The resulting relationship between the polishing gap and the ideal motor current was determined. In this embodiment, the relationship between the polishing gap and the ideal motor current was a functional relationship.

[0165] In this way, the corresponding relationship between the ideal motor current and the polishing gap can be more intuitively seen. Based on this, multiple components 2 to be polished under the same polishing conditions can be polished.

[0166] In some embodiments, if the sampling period for collecting the second instantaneous current data is recorded as t1, the shortest switching time between two adjacent track points to be processed on the component to be polished 2 is recorded as t2;

[0167] Methods include:

[0168] judge 、 Does the relationship between satisfy the formula:

[0169] ;

[0170] If not, the sampling frequency of the control unit for collecting the second instantaneous current data is adjusted until the above formula is satisfied and the sampling frequency is 1 / t1;

[0171] In this embodiment, the above formula gives the corresponding relationship between the two time elements, namely: when the moving component 6 adjusts the polishing module 3, sampling can be performed once within a single sampling cycle, avoiding the sampling cycle being too long resulting in the sampling frequency being too slow, making the sampling frequency mismatch with the execution position of the processing point, resulting in the inability to know the current state of the second instantaneous current data, affecting the accuracy of the corresponding motor current signal acquisition.

[0172] In some embodiments, t2 = ΔL / V max , where V max is the maximum moving speed of the moving assembly 6, and ΔL represents the distance between two adjacent track points to be processed on the component to be polished 2.

[0173] In some embodiments, the method further comprises:

[0174] When the moving component 6 drives the polishing module to move from the first track point to the second track point, the second instantaneous current data collected by the control unit during the movement is filtered, and the filtered second instantaneous current data is compared with the ideal motor current under the current polishing gap;

[0175] If the number of second instantaneous current data collected by the control unit during the movement is recorded as a, then a satisfies the following formula:

[0176] .

[0177] In this embodiment, this method can avoid the influence of random signals and mutation signals generated during the second instantaneous current data measurement on the measurement result of the second instantaneous current data, thereby making the adjustment of the polishing gap more accurate.

[0178] In some embodiments, the difference between the upper threshold and the lower threshold in the preset removal function variation range is set to ±RF max , the corresponding current output value of the drive motor is A0±ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude;

[0179] The moving component 6 is controlled to process the component to be processed, and the error between the second instantaneous current detected by the detection circuit and the ideal instantaneous current is within a preset error range, including:

[0180] If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A′′ ], then the removal function of the current processing is recorded as the theoretically set removal function RF0;

[0181] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then record the motor current data A of the current processing point i , and then calculate the corresponding removal function RF according to the corresponding relationship i for:

[0182]

[0183] If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current removal function RF i ±|RF max |,|RF max | represents the set maximum removal function. During the adjustment process, the corresponding processing point (X i ,Y i ) corresponding to the removal function RF i , get the set of variable removal functions {RF i}. Combined with the variable removal function set {RF i Secondary processing is performed to achieve the high-precision magnetorheological machining requirements. This process does not require calibration of parameters such as gravity compensation and is unaffected by the weight of the robotic magnetorheological machining equipment's magnetorheological machining module, the equipment's own operating accuracy, operating speed, posture, inertia, and other factors. The accuracy of the measured data is limited only by the current measurement accuracy of the second instantaneous current data, resulting in more accurate measurement results and eliminating the need for additional equipment such as high-precision force sensors, thus reducing equipment costs.

[0184] In all the above embodiments, all preset and set values ​​and ranges are adaptively set and adjusted according to actual conditions, and the present invention does not limit this.

[0185] 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.

[0186] 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 processing device based on motor current regulation, characterized in that: The device comprises: A polishing assembly, comprising a drive motor and a polishing module, wherein the drive motor is used to drive the polishing module to move; a moving assembly, rigidly connected to the polishing assembly, for driving the polishing assembly to move to the position of the element to be polished, and for adjusting the polishing gap between the polishing module and the element to be polished and the working position of the polishing assembly; a control unit for controlling the polishing module to perform fixed-point processing on the component to be polished with different supply parameters, collecting instantaneous current of the drive motor in real time, and adjusting the supply parameters according to the instantaneous current; or recording the removal function during processing to obtain a variable removal function set, using the variable removal function set as output for the next processing to perform secondary processing on the component to be polished; The supply parameters include the nozzle position of the nozzle in the polishing module and the supply height of the supply system.

2. The magnetorheological processing device based on motor current regulation according to claim 1, characterized in that: In the control unit: Calculating a correspondence between the supply parameter and a set ideal motor current according to first polishing data, wherein the first polishing data includes first instantaneous current data of the driving motor under the set supply parameter; and collecting second instantaneous current data in real time, and comparing the second instantaneous current data with the ideal motor current corresponding to the current supply parameter in the corresponding relationship; if a difference between the two exceeds a preset error range, adjusting the current supply parameter so that the difference between the second instantaneous current data collected after the supply parameter adjustment and the ideal motor current is within the preset error range; The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module at a constant speed to polish the component to be polished.

3. The magnetorheological processing device based on motor current regulation according to claim 1, characterized in that: The polishing module comprises: A magnetorheological mounting frame is connected to the moving assembly; the driving motor is arranged on the magnetorheological mounting frame; A polishing wheel is arranged on the magnetorheological mounting frame, and the driving motor drives the polishing wheel to rotate; a magnet, disposed on the magnetorheological mounting frame and close to a working point of the polishing wheel; a magnetorheological medium connected to the polishing wheel, the magnetorheological medium being driven by the polishing wheel to enter the magnetic field working area of ​​the magnet to form a magnetorheological ribbon, wherein the magnetorheological ribbon has a size parameter that changes with the polishing gap and the magnetic field strength generated by the magnet, and is used to polish the component to be polished; a nozzle, mounted on the magnetorheological mounting frame via a nozzle mounting seat, for providing the magnetorheological medium to the polishing wheel, the nozzle mounting seat adjusting the position of the nozzle; A supply system is connected to the nozzle and supplies the magnetorheological medium to the nozzle.

4. The magnetorheological processing device based on motor current regulation according to claim 1, characterized in that: The supply system includes a liquid pump, a supply mounting bracket, a supply motor and a ball screw; wherein, the supply motor and the ball screw are arranged on the supply mounting bracket, so that the supply motor drives the ball screw to rotate; the liquid pump is arranged on the ball screw, so that the ball screw drives the liquid pump to move, thereby changing the supply height; the liquid pump transports magnetorheological fluid to the nozzle through a pipeline.

5. The magnetorheological processing device based on motor current regulation according to claim 3, 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 nozzle position.

6. A magnetorheological machining method based on motor current regulation of nozzles, according to the magnetorheological machining device based on motor current regulation according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element; The control unit calculates a correspondence between a nozzle position and a set ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected at different set nozzle positions; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current nozzle position in the correspondence. If a difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the control unit controls the polishing module to adjust the current nozzle position or nozzle aperture so that the difference between the adjusted second instantaneous current data and the ideal motor current is within the preset error range. The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module at a constant speed to polish the component to be polished.

7. The magnetorheological machining method based on motor current regulation nozzle according to claim 6, characterized in that: If the current nozzle position NL i The adjustment range to or beyond the upper limit threshold of the preset error range is recorded as +ΔNL max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude; By the current nozzle position NL i The adjustment range to or beyond the lower limit threshold of the preset error range is recorded as -ΔNL max , the corresponding current output value of the drive motor is A0-ΔA max ; Control the polishing module to the current nozzle position NL i Adjustments include: If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to control the polishing module to the current nozzle position NL i Make adjustments; If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then control the polishing module according to the corresponding relationship F na For the current nozzle position NL i Adjust according to the following formula: ； If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current nozzle position NL i Directly adjust to NL0±ΔNL max NL0 represents the initial nozzle position, so that the second instantaneous current data A corresponding to the adjusted nozzle position is i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

8. A magnetorheological machining method based on motor current regulation supply height, according to the magnetorheological machining device based on motor current regulation according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element; The control unit calculates a correspondence between the supply height and a set ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected at different set supply heights; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current supply height in the correspondence. If a difference between the second instantaneous current data and the ideal motor current exceeds a preset error range, the control unit controls the polishing module to adjust the current supply height so that the difference between the second instantaneous current data collected after adjustment and the ideal motor current is within the preset error range. The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module at a constant speed to polish the component to be polished.

9. The magnetorheological machining method based on adjusting the supply height of the motor current according to claim 8, characterized in that: If the current supply height SP i The adjustment range to the upper limit threshold of the preset error range is recorded as +ΔSP max , the corresponding current output value of the drive motor is A0+ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude; By the current supply height SP i The adjustment range to the lower limit threshold of the preset error range is recorded as -ΔSP max , the corresponding current output value of the drive motor is A0-ΔA max ; Control the polishing module to supply the current height SP i Adjustments include: If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], it is not necessary to control the polishing module to supply the current height SP i Make adjustments; If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then control the polishing module to combine the corresponding relationship F pa Current supply height SP i Adjust according to the following formula: ； If the second instantaneous current data A of the current driving motor i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current supply height SP i Directly adjust to SP0±ΔSP max , SP0 represents the initially set supply height, so that the second instantaneous current data A corresponding to the adjusted supply height i Return to the permissible range of variation [A ′ ,A ′′ ]middle.

10. A magnetorheological machining method based on motor current regulation to remove function variation, the magnetorheological machining device based on motor current regulation according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: The moving assembly drives the polishing assembly to move to the location of the test optical element, and makes the polishing module contact with the test optical element; The control unit calculates a correspondence between a removal function and an ideal motor current based on first polishing data, the first polishing data including real-time current data of the drive motor collected under different set removal functions; and collects second instantaneous current data in real time, and compares the second instantaneous current data with the ideal motor current corresponding to the current removal function in the correspondence. If a difference between the second instantaneous current data and the ideal motor current corresponding to the current removal function exceeds a preset error range, the control unit records the motor current corresponding to the current removal function. After completing one machining operation, the control unit calculates the removal function for each machining point based on the recorded motor current to generate a set of removal functions. The second instantaneous current data is the current data of the driving motor collected in real time by the control unit when the driving motor drives the polishing module at a constant speed to polish the component to be polished; The moving assembly drives the polishing assembly to move to the initial processing position of the element to be polished and contact the element to be polished, and re-processes the element to be polished in combination with the variable removal function set. The processing amount of each processing point on the element to be polished is determined by the variable removal function set, ensuring the accuracy of material removal using the variable removal function in the actual processing process.

11. The magnetorheological machining method based on motor current regulation and elimination function variation according to claim 10, characterized in that: Set the upper and lower thresholds of the preset removal function range to ±RF max , the corresponding current output value of the drive motor is A0±ΔA max , A0 represents the ideal motor current, ΔA max Indicates the corresponding current adjustment amplitude; If the current second instantaneous current data A i Does not exceed the permissible range of variation [A ′ ,A ′′ ], there is no need to change the current data A of the processing point i The corresponding removal function; If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |<|A0±ΔA max |, then it is necessary to follow the corresponding relationship F ra Calculate the current removal function RF i : ； If the current second instantaneous current data A i Beyond the permissible range of variation [A ′ ,A ′′ ] and|A i |≥|A0±ΔA max |, then the current removal function RF i ±|RF max |,|RF max | represents the set maximum removal function; After the processing is completed, based on the current data A recorded at each processing point i Calculate the corresponding processing point (X i ,Y i ) corresponding to the removal function RF i , get the set of variable removal functions {RF i }, in the next processing, the function set {RF i }As the input of processing parameters, it can achieve accurate material removal and improve the certainty of processing.

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