Magnetorheological machining device and method for adjusting machining rotating speed based on motor current

Abstract

The invention relates to the technical field of magneto-rheological, in particular to a magneto-rheological machining device and method for adjusting the machining rotating speed based on motor current, the device comprises a polishing assembly, a moving assembly and a control unit, and when a to-be-polished element is polished by a polishing module, first instantaneous currents corresponding to different machining rotating speeds are collected; the corresponding relation between the machining rotating speed and the ideal motor current is calculated, then the second instantaneous current data is judged based on the corresponding relation, whether the machining rotating speed is adjusted or not is determined according to the judgment result, and the process does not need the step of calibrating parameters such as gravity compensation. The precision of the measurement data is only limited by the current measurement precision of the second instantaneous current data, the measurement result is more accurate, and the equipment cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetorheological processing, and particularly relates to a magnetorheological processing device and method for adjusting the processing speed based on motor current. Background Art

[0002] Magnetorheological finishing (MRF) is an advanced optical manufacturing technology developed in recent years. It has many advantages such as a stable removal function, controllable edge effect, small subsurface damage layer, no replication effect, strong shape correction ability, and high processing accuracy. Therefore, magnetorheological finishing technology has received extensive attention in high-precision optical processing. The existing magnetorheological finishing processing centers mainly integrate the polishing module on a numerically controlled machine tool. However, some deficiencies of the numerically controlled machine tool (such as low degrees of freedom, large floor area, high cost, etc.) limit the deviation of aspherical surfaces and it is difficult to perform precise pose control along the surface normal. In view of these deficiencies of the numerically controlled machine tool, 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 floor area, large processing range, low cost, etc., making up for the deficiencies of numerically controlled machine tools. Therefore, when the polishing module is integrated into an industrial robot, high-precision processing of large-aperture complex-curved optical elements can be theoretically achieved. However, due to the influence of factors such as processing, assembly, load, trajectory planning, and reduction ratio, the end-effector accuracy of the robot is relatively low, and the polishing gap changes greatly during the processing. At the same time, magnetorheological finishing technology is an optical processing technology with a high degree of certainty of the removal function, and has high requirements for the change of the polishing gap during the polishing process. Generally, the change of the polishing gap in a magnetorheological numerically controlled processing center is in the order of dozens of micrometers (PV < 0.1 mm), while the trajectory accuracy of common commercial robots is generally in the sub-millimeter to millimeter range, which cannot meet the requirements of magnetorheological finishing technology for the change of the polishing gap during high-precision polishing.

[0003] At present, the force-position control method has gradually become a new type of constant-force regulation and polishing control method for robots. A common application method is to place a force sensor between the processing tool and the robot. First, the gravity calibration of the force sensor is carried out to ensure the accuracy of measurement. The pose error is calculated by measuring the change of force, and then the robot pose error is compensated by means of the robot body or other motion compensation mechanisms to achieve constant-force control. The high-efficiency processing of large-aperture optical elements relies on the magnetorheological processing equipment with large-size polishing wheels, and the weight of the magnetorheological processing module of large-size polishing wheels is generally over a hundred kilograms. However, for a magnetorheological processing module weighing over a hundred kilograms, the force change caused by the robot pose error is only dozens of Newtons. When performing high-precision processing, the force needs to be constant at several Newtons or even a fraction of a Newton, which requires the absolute measurement accuracy of measurement equipment such as force sensors to reach one ten-thousandth, and the force sensor also needs to be in variable-speed and variable-attitude motion. Force sensors that meet these requirements are often extremely expensive, greatly 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 for adjusting the processing speed based on motor current, so as to adjust the processing speed in real time by sensing the motor current, and solve the problem that the regulation of the polishing wheel in the prior art requires data acquisition with the aid of a high-precision force sensor and the high cost of the high-precision force sensor.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows: A magnetorheological processing device for adjusting the processing speed based on motor current, comprising: A polishing assembly, including a driving motor and a polishing module, the driving motor is used to drive the polishing module to move; A moving assembly, rigidly connected to the polishing assembly, is used to drive the polishing assembly to move to the position where the element to be polished is located; A control unit, which controls the polishing module to perform fixed-point processing on the element to be polished at different processing speeds, and real-time collects the instantaneous current of the driving motor, and adjusts the processing speed according to the instantaneous current; The processing speed includes the polishing wheel speed of the polishing wheel in the polishing module and the liquid pump speed of the liquid pump.

[0006] Furthermore, in the control unit: Calculate the corresponding relationship between the processing rotation speed and the set ideal motor current according to the first polishing data. The first polishing data includes the first instantaneous current data of the driving motor at the set processing rotation speed; and collect the second instantaneous current data in real time, and compare the second instantaneous current data with the ideal motor current corresponding to the current processing rotation speed in the corresponding relationship. If the difference between the two exceeds the preset error range, control the polishing component to adjust the current processing rotation speed so that the difference between the second instantaneous current data collected after the processing rotation speed is adjusted and the ideal motor current is within the preset error range; The second instantaneous current data is the current data of the current driving motor collected in real time by the control unit when the driving motor drives the polishing module to polish the element to be polished at a constant rotation speed.

[0007] Further, the polishing module includes: A magnetorheological mounting bracket, connected to the moving component; a driving motor is arranged on the magnetorheological mounting bracket, and a polishing wheel is arranged on the magnetorheological mounting bracket; the driving motor drives the polishing wheel to rotate and adjusts the rotation speed of the polishing wheel; A magnet, arranged on the magnetorheological mounting bracket and close to the working point of the polishing wheel; A magnetorheological medium, connected to the polishing wheel. The magnetorheological medium is used to enter the magnetic field working area of the magnet under the drive of the polishing wheel to form a magnetorheological ribbon. The size parameters of the magnetorheological ribbon change with the polishing gap and the magnetic field strength, and are used to polish the element to be polished; A nozzle, arranged on the magnetorheological mounting bracket through a nozzle mounting seat. A liquid pump transports the magnetorheological fluid medium to the nozzle, and the nozzle provides the magnetorheological fluid medium to the polishing wheel.

[0008] A magnetorheological processing method for adjusting the rotation speed of a polishing wheel based on motor current. According to the magnetorheological processing device for adjusting the processing rotation speed based on motor current provided by the present invention, the method includes the following steps: The moving component drives the polishing component to move to the position where the test optical element is located, and makes the polishing module contact the test optical element; The control unit calculates the corresponding relationship between the rotation speed of the polishing wheel and the ideal motor current according to the first polishing data. The first polishing data includes the real-time current data of the driving motor collected at different set rotation speeds of the polishing wheel; and collect the second instantaneous current data in real time, and compare the second instantaneous current data with the ideal motor current corresponding to the current rotation speed of the polishing wheel in the corresponding relationship. If the difference between the two exceeds the preset error range, control the driving motor to adjust the current rotation speed of the polishing wheel so that the difference between the second instantaneous current data collected after the adjustment and the ideal motor current is within the preset error range; The second instantaneous current data is the current data of the current driving motor collected in real time by the control unit when the driving motor drives the polishing module to polish the element to be polished at a constant rotation speed.

[0009] Further, if the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the polishing wheel speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest time for switching between two adjacent machining track points on the component to be polished is denoted as t3; The method includes: Determine whether the relationship among t1, t2, and t3 satisfies the formula: ; If not, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and the sampling frequency is 1 / t1.

[0010] Further, the maximum change adjustment amount is the adjustment amplitude corresponding to adjusting from the set ideal polishing wheel speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔV 1max ; t2 = ΔV 1max / dV1, t3 = ΔL / V max , where dV1 is the fastest adjustment rate of the polishing wheel speed, V max is the highest moving speed of the moving component, and ΔL represents the distance between two adjacent machining track points on the component to be polished.

[0011] Further, the method further includes: When the moving component drives the polishing module to move from the first track point to the second track point, filter the second instantaneous current data collected by the control unit during the moving process, and compare the filtered second instantaneous current data with the ideal motor current at the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the moving process is denoted as a, then a satisfies the following formula: .

[0012] Further, if the adjustment amplitude for adjusting from the current polishing wheel speed V i to the upper threshold of the preset error range is denoted as +ΔV 1max , the current output value of the corresponding drive motor is A0 + ΔA max , A0 represents the ideal motor current, and ΔA max represents the corresponding current adjustment amplitude; The adjustment amplitude for adjusting from the polishing wheel speed V i to the lower threshold of the preset error range is denoted as -ΔV 1max , and the current output value of the corresponding drive motor is A0 - ΔA max ; Control the drive motor for the current polishing wheel speed V iThe adjustments include: If the current second instantaneous current data A i does not exceed the allowable variation range [A ′ , A ′′ , there is no need to control the drive motor to adjust the current polishing wheel speed V i ; If the second instantaneous current data A of the current drive motor i exceeds the allowable variation range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the drive motor to adjust the current polishing wheel speed V va according to the corresponding relationship F i to adjust according to the following formula: ; If the second instantaneous current data A of the current drive motor i exceeds the allowable variation range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current polishing wheel speed V i is adjusted to V0 ± ΔV 1max , where V0 represents the initially set polishing wheel speed; so that the second instantaneous current data A corresponding to the adjusted polishing wheel speed i returns to the allowable variation range [A ′ , A ′′ .

[0013] A magnetorheological processing method for adjusting the speed of a liquid pump based on motor current, according to the magnetorheological processing device for adjusting the processing speed based on motor current provided by the present invention, the method includes the following steps: The moving component drives the polishing component to move to the position where the test optical element is located and makes the polishing module contact the test optical element; The control unit calculates the corresponding relationship between the liquid pump speed and the ideal motor current according to the first polishing data, and the first polishing data includes the real-time current data of the drive motor collected at different set liquid pump speeds; and the second instantaneous current data is collected in real time and compared with the ideal motor current corresponding to the current liquid pump speed in the corresponding relationship. If the difference between the two exceeds the preset error range, the control unit controls the polishing module to adjust the current liquid pump speed 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 current drive motor collected in real time by the control unit when the drive motor drives the polishing module to polish the element to be polished at a constant speed.

[0014] Further, if the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the liquid pump speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest time for switching between two adjacent machining trajectory points on the element to be polished is denoted as t3; The method includes: Judging whether the relationship among t1, t2, and t3 satisfies the following formula: ; If not satisfied, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and set the sampling frequency to 1 / t1.

[0015] Further, the maximum change adjustment amount is the adjustment amplitude corresponding to adjusting from the set ideal liquid pump speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔSV max ; t2 = ΔSV max / SV max t3 = ΔL / V max where SV max is the maximum speed adjustment rate of the liquid pump, V max is the highest moving speed of the moving component, and ΔL represents the distance between two adjacent machining trajectory points on the element to be polished.

[0016] Further, the method further includes: When the moving component drives the polishing module to move from the first trajectory point to the second trajectory point, filter the second instantaneous current data collected by the control unit during the movement, and compare the filtered second instantaneous current data with the ideal motor current at the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the movement is denoted as a, then a satisfies the following formula: .

[0017] Further, if the adjustment amplitude for adjusting from the current liquid pump speed SV i to the upper threshold of the preset error range is denoted as +ΔSV max , the corresponding current output value of the drive motor is A0 + ΔA max , A0 represents the ideal motor current, and ΔA max represents the corresponding current adjustment amplitude; From the current liquid pump speed SV iThe adjustment amplitude adjusted to the lower threshold of the preset error range is denoted as -ΔSV max , and the current output value of the corresponding drive motor is A0 - ΔA max ; Controlling the polishing module to adjust the current liquid pump speed SV i includes: If the current second instantaneous current data A i does not exceed the allowable change range [A ′ , A ′′ , there is no need to control the polishing module to adjust the current liquid pump speed SV i ; If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the polishing module to combine the corresponding relationship F sa to adjust the current liquid pump speed SV i according to the following formula: ; If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current liquid pump speed SV i is adjusted to SV0 ± ΔSV max , where SV0 represents the initially set liquid pump speed; so that the second instantaneous current data A corresponding to the adjusted liquid pump speed i returns to the allowable change range [A ′ , A ′′ .

[0018] Compared with the prior art, the present invention can achieve the following beneficial effects: In the magnetorheological processing device and method for adjusting the processing speed based on the motor current according to the present invention, by using the relationship between the polishing module and the motor current, when the polishing module polishes the element to be polished, different processing speeds and the corresponding first instantaneous current data are collected respectively to obtain their respective corresponding relationships. Then, the second instantaneous current data is judged through these corresponding relationships, and whether to adjust the processing speed is determined according to the judgment result. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by factors such as the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy of the equipment itself, the running speed, the posture, the inertia, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data, and the measurement result is more accurate. There is no need to add equipment such as high-precision force sensors, reducing the equipment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 FIG. is a schematic structural diagram of the magnetorheological processing device for adjusting the processing speed based on the motor current according to the embodiment of the present invention from one perspective; Figure 2 FIG. is a schematic structural diagram of the magnetorheological processing device for adjusting the processing speed based on the motor current according to the embodiment of the present invention from another perspective; Figure 3 FIG. is a schematic structural diagram of the liquid pump according to the embodiment of the present invention.

[0020] DESCRIPTION OF THE REFERENCE NUMERALS 1. Polishing platform; 2. Element to be polished; 3. Polishing module; 4. Driving motor; 5. Control unit; 6. Moving component; 7. Polishing wheel; 8. Liquid pump; 9. Magnetorheological mounting bracket; 10. Transmission belt; 11. Nozzle; 12. Magnet; 13. Mounting bracket; 14. Liquid pump main body; 15. Cooling chamber; 16. Magnetorheological fluid storage chamber; 17. Cooling water inlet; 18. Magnetorheological fluid inlet; 19. Cooling water outlet; 20. Magnetorheological fluid outlet. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation to the present invention.

[0022] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0025] The present invention will be described in detail below with reference to the drawings and in combination with embodiments.

[0026] As Figures 1 to 2 shown, the magnetorheological processing device for adjusting the processing speed based on the motor current according to the embodiment of the present invention includes a polishing platform 1, a polishing assembly, a moving assembly 6 and a control unit 5. A component to be polished 2 is arranged on the polishing platform 1; the polishing assembly includes a polishing module 3 and a driving motor 4. The polishing module 3 is used for performing a polishing process on the component to be polished 2, and the driving motor 4 is used for driving the polishing module 3 to move. The moving assembly 6 is rigidly connected to the polishing assembly and is used for driving the polishing assembly to move to the position where the component to be polished 2 is located, and for adjusting the polishing gap between the polishing module 3 and the component to be polished 2, as well as the working position of the polishing assembly; the control unit 5 controls the polishing module 3 to perform fixed-point processing on the component to be polished 2 at different processing speeds, and real-time collects the instantaneous current of the driving motor 4, and adjusts the processing speed according to the instantaneous current. Specifically, the processing speed includes the polishing wheel speed of the polishing wheel 7 in the polishing module 3 and the liquid pump speed of the liquid pump 8.

[0027] In this embodiment, the polishing platform 1 refers to the working platform for experiments, on which the element 2 to be polished, the test optical element for test processing, and other polishing components are placed. For example, the magnetorheological medium required for polishing, the supporting tooling for the element 2 to be polished, etc. Among them, the element 2 to be polished is the component that needs to be processed by magnetorheological polishing.

[0028] In this embodiment, the polishing module 3 includes a magnetorheological mounting frame 9, a nozzle 11, and a magnet 12. Among them, the magnetorheological mounting frame 9 is rigidly connected to the moving component 6, and the driving motor 4 is arranged on the magnetorheological mounting frame 9; the polishing wheel 7 is arranged on the magnetorheological mounting frame 9, and the output end of the driving motor 4 is connected to the bearing of the polishing wheel 7 through a transmission belt 10, so that the driving motor 4 controls the polishing wheel 7 to rotate; the magnet 12 is installed on the magnetorheological mounting frame 9 and close to the working point of the polishing wheel 7 (in the embodiment of the present invention, it is stipulated that the working point of the polishing wheel 7 is the closest point to the surface of the element 2 to be polished along the normal direction of the surface of the element 2 to be polished); the liquid pump 8 is installed on one side of the polishing platform 1 through the mounting frame 13, the liquid pump 8 conveys the magnetorheological medium to the nozzle 11, the nozzle 11 is installed on the magnetorheological mounting frame 9 along the rotation direction of the polishing wheel 7, and is connected to the polishing wheel 7 through the magnetorheological medium. The magnetorheological medium is used to enter the magnetic field working area of the magnet 12 under the drive of the polishing wheel 7 to form a magnetorheological ribbon. The size parameters of the magnetorheological ribbon change with the polishing gap and the magnetic field strength, and are used to polish the element 2 to be polished.

[0029] The overall structure of the liquid pump 8 is as Figure 3 shown, and it includes a liquid pump main body 14, a cooling chamber 15, and a magnetorheological fluid storage chamber 16. In the embodiment of the present invention, the liquid pump main body 14 uses the DFLD vertical multi-stage pump of Shanghai Orient Pump Industry Co., Ltd. The liquid pump main body 14 is used to supply the magnetorheological fluid; the cooling chamber 15 is mainly used to store cooling water and cool down the magnetorheological fluid; the magnetorheological fluid storage chamber 16 is mainly used for storing the magnetorheological fluid. When the liquid pump 8 works, the cooling water enters the cooling chamber 15 from the cooling water inlet 17, and the magnetorheological fluid enters the liquid pump main body 14 from the magnetorheological fluid inlet 18 through the magnetorheological fluid storage chamber 16; the cooling water completes the cooling of the magnetorheological fluid in the cooling chamber 15 and then is discharged from the cooling water outlet 19; the cooled magnetorheological fluid is output from the magnetorheological fluid outlet 20 and conveyed to the nozzle 11 through a pipeline. The rotation speed of the liquid pump main body 14, that is, the liquid pump speed, is adjusted by an electric motor.

[0030] The motors of the drive motor 4, the moving component 6, and the liquid pump 8 are respectively connected to the control unit 5 to form their respective communication lines, enabling the control unit 5 to receive and send signals through the corresponding communication lines. During operation, the control unit 5 gives a control instruction to the drive motor 4, and the drive motor 4 adjusts the polishing wheel speed of the polishing wheel 7; the control unit 5 gives a control instruction to the motor of the liquid pump 8, and the motor adjusts the speed of the liquid pump 8 in real time, thereby achieving the purpose of adjusting the liquid flow rate. Since a strong magnetic field region is generated around the polishing wheel 7 during the polishing operation, the communication lines avoid the strong magnetic field region to prevent the wires from being adsorbed to the polishing module 3 and affecting normal operation.

[0031] The moving component 6 can be a robotic arm or other robots with pose adjustment functions; optionally, the moving component 6 is a six-axis robotic arm, and the drive motor 4 is rigidly connected to the robotic arm through metal hardware, and the robotic arm drives the polishing component to complete the processing of the entire element 2 to be polished.

[0032] When the processing speed in the polishing module 3 changes, causing the shear force between the element 2 to be polished and the magnetorheological medium in the polishing module 3 to change, in order to maintain a constant polishing speed, the current of the drive motor 4 will ultimately change accordingly. The change in the processing speed is calculated by measuring the change in the current of the drive motor 4.

[0033] In this embodiment, the control unit 5 is used to obtain the first polishing data based on the current of the drive motor 4 at different processing speeds (i.e., the polishing wheel speed or the liquid pump speed) when the drive motor 4 drives the polishing module 3 to perform fixed-point polishing on the test optical element, and calculate the corresponding relationship between the processing speed and the ideal motor current according to the first polishing data. The first polishing data includes: the first instantaneous current data of the drive motor 4 at different processing speeds, and different processing speeds can be preset.

[0034] The first polishing data can be collected multiple times, and finally, the error between multiple sets of first polishing data is reduced by numerical calculation methods such as taking the mean or variance, and then the relationship between the ideal motor current and the processing speed is calculated according to the first polishing data.

[0035] In this embodiment, the control unit 5 calculates the corresponding relationship between different processing speeds and the ideal motor current through the correlation between the first instantaneous current data and the corresponding processing speed. With this as a reference, when polishing the element 2 to be polished, by comparing whether the difference between the second instantaneous current data corresponding to different polishing regions of the current element 2 to be polished and the ideal motor current is within the preset error range, if not, the processing speed is adjusted so 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 processing speed. This method can achieve the effect of real-time adjustment of the processing speed based on the corresponding relationship between the processing speed and the instantaneous current.

[0036] By using the relationship between the polishing module 3 and the motor current, when the polishing module 3 polishes the test optical element, different machining speeds and the corresponding first instantaneous current data are collected. Then, the corresponding relationship between the machining speed and the ideal motor current is calculated through the collected machining speed and the first instantaneous current data. After that, the second instantaneous current data is judged based on this relationship, and whether to adjust the machining speed of the element 2 to be polished is determined according to the judgment result. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by factors such as the weight of the magnetorheological machining module of the robot magnetorheological machining equipment, the running accuracy of the equipment itself, the running speed, the posture, the inertia, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data, and the measurement result is more accurate. There is no need to add equipment such as high-precision force sensors, reducing the equipment cost.

[0037] The polishing principle is specifically as follows: When the polishing wheel 7 polishes, the magnetorheological medium is affected by the magnetic field change and changes from a liquid state to a quasi-solid state, forming a Bingham fluid. By rotating the polishing wheel 7, the Bingham fluid exerts a shear force on the outer surface of the element 2 to be polished, realizing the polishing of the element 2 to be polished. The shear forces corresponding to different machining speeds are different. Therefore, the polishing effects achieved by different machining speeds are different. When the machining speed changes, the thickness of the magnetorheological ribbon of the magnetorheological medium placed in the polishing area changes, causing the shear force between the element 2 to be polished and the magnetorheological ribbon to change. In order to maintain a constant rotation speed, the current of the driving motor 4 will finally change accordingly. The corresponding relationship can be expressed by the following formula: ; where n represents the polishing wheel rotation speed, k represents the proportionality coefficient, U represents the voltage of the driving motor 4, F represents the force received by the driving motor 4 (i.e., the shear force), r represents the torque (i.e., the horizontal distance from the lowest point of the polishing wheel to the driving motor 4), and I represents the current of the driving motor 4. By measuring the change in the current of the driving motor 4, the change in the thickness of the magnetorheological ribbon in the polishing area is obtained, and then the change amount of the current working speed is calculated. Finally, the real-time regulation of the working speed change is realized by using the polishing module 3.

[0038] Based on the magnetorheological machining device for adjusting the machining speed based on the motor current described in the embodiment of the present invention, the embodiment of the present invention also provides a magnetorheological machining method for adjusting the machining speed based on the motor current, including a magnetorheological machining method for adjusting the polishing wheel rotation speed based on the motor current, and a magnetorheological machining method for adjusting the liquid pump rotation speed based on the motor current.

[0039] Embodiment 1: A magnetorheological processing method for adjusting the polishing wheel speed based on motor current. According to the magnetorheological processing device for adjusting the processing speed based on motor current provided by the embodiment of the present invention, combined with Figures 1 to 2 , the method comprises the following steps: The moving component 6 drives the polishing component to move to the position where the test optical element is located, and makes the polishing module 3 contact the test optical element; The control unit 5 calculates the corresponding relationship between the polishing wheel speed and the ideal motor current according to the first polishing data. The first polishing data includes the real-time current data of the driving motor 4 collected at different set polishing wheel speeds; and the second instantaneous current data is collected in real time and compared with the ideal motor current corresponding to the current polishing wheel speed in the corresponding relationship. If the difference between the two exceeds the preset error range, the driving motor 4 is controlled to adjust the current polishing wheel speed 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 4 collected in real time by the control unit 5 when the driving motor 4 drives the polishing module 3 to polish the element to be polished at a constant speed.

[0040] In this embodiment, it is necessary to first obtain the corresponding relationship between the ideal motor current and the polishing wheel speed respectively. The moving component 6 drives the polishing module 3 to move to the position where the test optical element is located 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 of the polishing module 3 in contact with the test optical element is denoted 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 improve the accuracy of the corresponding relationship between the ideal motor current and the polishing wheel speed respectively.

[0041] During the process of the polishing module 3 polishing the test optical element, the control unit 5 controls the driving motor 4 to set different polishing wheel speeds, collects the corresponding first instantaneous current data at different polishing wheel speeds, maps and stores the multiple sets of first instantaneous current data and the corresponding polishing wheel speeds to obtain the first polishing data, and the control unit 5 calculates the corresponding relationship between the polishing wheel speed and the ideal motor current according to the first polishing data.

[0042] After obtaining the corresponding relationship between the ideal motor current and the polishing wheel speed respectively, the polishing wheel speed of the polishing area of the element to be polished 2 can be adjusted according to this corresponding relationship, so that the second instantaneous current data corresponding to the current polishing wheel speed of the element to be polished 2 and the ideal motor current are within the same preset error range after adjustment.

[0043] By using the relationship between the polishing module 3 and the motor current, when the polishing module 3 polishes the element 2 to be polished, different polishing wheel speeds and the corresponding first instantaneous current data are respectively collected. Then, based on the collected polishing wheel speeds and the first instantaneous current data, the corresponding relationship between the polishing wheel speed and the ideal motor current is calculated. After that, the second instantaneous current data is judged according to this relationship, and whether to adjust the polishing wheel speed of the element 2 to be polished is determined according to the judgment result, so as to use the driving motor 4 to adjust the polishing wheel speed in real time. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by factors such as the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy, running speed, posture, inertia and other factors of the equipment itself. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data, the measurement result is more accurate, and there is no need to add equipment such as high-precision force sensors, reducing the equipment cost.

[0044] In some embodiments, the corresponding relationship between the polishing wheel speed and the ideal motor current is a functional curve relationship, and the functional curve relationship is obtained by fitting according to the discrete values of the polishing wheel speed V and the first instantaneous current data A. va It is: 。

[0045] In this embodiment, multiple polishing wheel speeds V correspond to multiple first instantaneous current data A, and both the polishing wheel speed V and the first instantaneous current data A are discrete values. Therefore, it is necessary to fit the discrete values.

[0046] Fitting process: Import the discrete data into the Matlab software, and complete the data fitting with the help of the polyfit fitting instruction of the Matlab software to solve the corresponding relationship between the polishing wheel speed and the ideal motor current parameters; The Polyfit fitting instruction is a basic general instruction of the matlab software. Finally, the corresponding relationship between the polishing wheel speed and the ideal motor current is obtained. In this embodiment, the corresponding relationship between the polishing wheel speed and the ideal motor current is a functional relationship.

[0047] In this way, the corresponding relationship between the ideal motor current and the polishing wheel speed can be more intuitively seen. Based on this, multiple elements 2 to be polished under the same polishing conditions can be polished.

[0048] In some embodiments, if the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the polishing wheel speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest time for switching between two adjacent to-be-processed trajectory points on the element 2 to be polished is denoted as t3; The method includes: Determine whether the relationship among t1, t2, and t3 satisfies the formula: ; If not, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and the sampling frequency is 1 / t1.

[0049] In this embodiment, the above formula gives the corresponding relationship among the three time elements, that is: within a single sampling period, the moving component 6 can adjust the polishing module 3 so that it moves to the polishing wheel speed corresponding to the ideal motor current respectively, and then performs the next sampling, avoiding too long sampling period resulting in too slow sampling frequency, making the sampling frequency not match the adjustment speed of the polishing wheel speed, 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 wheel speed.

[0050] In some embodiments, the maximum change adjustment amount is the adjustment amplitude from the set ideal polishing wheel speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔV 1max ; t2 = ΔV 1max / dV1, t3 = ΔL / V max , where dV1 is the fastest adjustment rate of the polishing wheel speed, V max is the maximum moving speed of the moving component 6, and ΔL represents the distance between two adjacent to-be-machined trajectory points on the to-be-polished element 2.

[0051] In some embodiments, the method further includes: When the moving component 6 drives the polishing module to move from the first trajectory point to the second trajectory point, filter the second instantaneous current data collected by the control unit during the movement, and compare the filtered second instantaneous current data with the ideal motor current under the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the movement is denoted as a, then a satisfies the following formula: .

[0052] 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 result of the second instantaneous current data, making the adjustment of the polishing gap more accurate. In some embodiments, if the adjustment amplitude from the current polishing wheel speed V i to the upper threshold of the preset error range is denoted as +ΔV 1max , the current output value of the corresponding drive motor is A0 + ΔA max , A0 represents the ideal motor current, ΔA maxIndicates the corresponding current adjustment amplitude; The adjustment amplitude from the polishing wheel rotation speed V i Adjusted to the lower threshold of the preset error range is denoted as -ΔV 1max , and the current output value of the drive motor is A0 - ΔA max ; Controlling the drive motor 4 to adjust the current polishing wheel rotation speed V i includes the following: If the current second instantaneous current data A i does not exceed the allowable change range [A ′ , A ′′ , there is no need to control the drive motor 4 to adjust the current polishing wheel rotation speed V i ; If the current second instantaneous current data A i exceeds the allowable change range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the drive motor 4 to combine the corresponding relationship F va to adjust the current polishing wheel rotation speed according to the following formula:

[0053] If the current second instantaneous current data A of the drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current polishing wheel rotation speed V i is adjusted to V0 ± ΔV 1max , where V0 represents the initially set polishing wheel rotation speed; so that the second instantaneous current data A corresponding to the adjusted polishing wheel rotation speed i returns to the allowable change range [A ′ , A ′′ .

[0054] By adjusting the polishing wheel rotation speed, the current A at the next machining point i+1 is within the allowable change range, meeting the requirements of high-precision magnetorheological machining.

[0055] Example 2: A magnetorheological machining method based on adjusting the liquid pump rotation speed according to the motor current. According to the magnetorheological machining device based on adjusting the machining rotation speed according to the motor current provided by the embodiment of the present invention, combined with Figures 1 to 3 , the method includes the following steps: The moving component 6 drives the polishing component to move to the position where the test optical element is located, and makes the polishing module 3 contact the test optical element; The control unit 5 calculates the corresponding relationship between the liquid pump speed and the ideal motor current according to the first polishing data. The first polishing data includes the real-time current data of the driving motor 4 collected at the set liquid pump speed; and the 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 liquid pump speed in the corresponding relationship. If the difference between the two exceeds the preset error range, the control polishing module 3 adjusts the liquid pump speed so that the difference between the second instantaneous current data collected and the ideal motor current is within the preset error range; The second instantaneous current data is the current data of the current driving motor 4 collected in real time by the control unit 5 when the driving motor 4 drives the polishing module 3 to polish the element to be polished at a constant speed.

[0056] In this embodiment, it is necessary to first obtain the corresponding relationship between the ideal motor current and the liquid pump speed. The moving component 6 drives the polishing module 3 to move to the position where the test optical element is located 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 of the polishing module 3 in contact with the test optical element is denoted 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 improve the accuracy of the corresponding relationship between the ideal motor current and the liquid pump speed.

[0057] During the process of the polishing module 3 polishing the test optical element, the control unit 5 controls the polishing module 3 to set different liquid pump speeds, collects the corresponding first instantaneous current data at different liquid pump speeds, maps and stores multiple sets of first instantaneous current data and the corresponding liquid pump speeds to obtain the first polishing data, and the control unit 5 calculates the corresponding relationship between the liquid pump speed and the ideal motor current according to the first polishing data.

[0058] After obtaining the corresponding relationship between the ideal motor current and the liquid pump speed, the liquid pump speed of the polishing area of the element to be polished 2 can be adjusted according to the corresponding relationship, so that the second instantaneous current data corresponding to the adjusted current liquid pump speed and the ideal motor current are within the same preset error range. And this process does not require calibration steps for parameters such as gravity compensation, and is not affected by factors such as the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy, running speed, posture, inertia of the equipment itself, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current data, and the measurement result is more accurate. There is no need to add equipment such as high-precision force sensors, which reduces the equipment cost.

[0059] In some embodiments, the correspondence between the liquid pump speed and the ideal motor current is a functional curve relationship, and the functional curve relationship is obtained by fitting based on the discrete values of the liquid pump speed SV and the first instantaneous current data A. sa as follows: 。

[0060] In this embodiment, multiple liquid pump speeds SV correspond to multiple first instantaneous current data A. Both the liquid pump speed SV and the first instantaneous current data A are discrete values. Therefore, it is necessary to fit the discrete values.

[0061] Fitting process: Import the discrete data into Matlab software, and complete the data fitting with the help of the polyfit fitting instruction in Matlab software to solve the correspondence between the liquid pump speed and the ideal motor current parameters; The Polyfit fitting instruction is a basic general instruction in matlab software. Finally, the correspondence between the liquid pump speed and the ideal motor current is obtained. In this embodiment, the correspondence between the liquid pump speed and the ideal motor current is a functional relationship.

[0062] In this way, the correspondence between the ideal motor current and the liquid pump speed can be more intuitively seen. Based on this, multiple elements to be polished 2 under the same polishing conditions can be polished.

[0063] In some embodiments, if the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the liquid pump speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest time for switching between two adjacent machining trajectory points on the element to be polished 2 is denoted as t3; The method includes: Judge whether the relationship between t1, t2, and t3 satisfies the formula: ; If not, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and the sampling frequency is 1 / t1.

[0064] In this embodiment, the above formula gives the correspondence between the three time elements, that is: within a single sampling period, the moving component 6 can adjust the polishing module 3 so that it moves to the liquid pump speed corresponding to the ideal motor current and then performs the next sampling, avoiding the sampling period being too long resulting in too slow sampling frequency, making the sampling frequency not match or the adjustment not timely with the adjustment speed of the liquid pump speed, resulting in the inability to know the current state of the second instantaneous current data and affecting the automatic compensation function of the liquid pump speed.

[0065] In some embodiments, the maximum variation adjustment amount is the adjustment amplitude corresponding to adjusting the set ideal liquid pump rotation speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔSV max ; t2 = ΔSV max / SV max , t3 = ΔL / V max , where SV max is the maximum rotation speed adjustment rate of the liquid pump, V max is the highest moving speed of the moving component 6, and ΔL represents the distance between two adjacent machining trajectory points on the element 2 to be polished.

[0066] In some embodiments, the method further includes: When the moving component 6 drives the polishing module to move from the first trajectory point to the second trajectory point, filter the second instantaneous current data collected by the control unit during the movement, and compare the filtered second instantaneous current data with the ideal motor current at the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the movement is denoted as a, then a satisfies the following formula: .

[0067] 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 result of the second instantaneous current data, making the adjustment of the polishing gap more accurate. In some embodiments, if the adjustment amplitude from the current liquid pump rotation speed SV i to the upper threshold of the preset error range is denoted as +ΔSV max , the corresponding current output value of the drive motor 4 is A0 + ΔA max , A0 represents the ideal motor current, and ΔA max represents the corresponding current adjustment amplitude; the adjustment amplitude from the current liquid pump rotation speed SV i to the lower threshold of the preset error range is denoted as -ΔSV max , and the corresponding current output value of the drive motor 4 is A0 - ΔA max ; Controlling the polishing module 3 to adjust the current liquid pump rotation speed SV i includes: If the current second instantaneous current data A i does not exceed the allowable variation range [A ′ , A ′′ , there is no need to adjust the current liquid pump rotation speed SV i ; If the current second instantaneous current data A iExceed the allowable variation range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the polishing module 3 to combine with the corresponding relationship F sa Adjust the current liquid pump speed SV i According to the following formula: ; If the second instantaneous current data A of the current drive motor i Exceed the allowable variation range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current liquid pump speed SV i Is adjusted to SV0 ± ΔSV max , where SV0 represents the initially set liquid pump speed, so that the second instantaneous current data A corresponding to the adjusted liquid pump speed i Returns to the allowable variation range [A ′ , A ′′ .

[0068] Based on the change of the liquid pump speed SV i For regulation, so that the current A at the next machining point i+1 Is within the allowable variation range to meet the requirements of magnetorheological high-precision machining.

[0069] In all the above embodiments, all the preset and set values and ranges are adaptively set and adjusted according to the actual situation, and the present invention does not limit this.

[0070] It should be understood that various forms of the flow shown above can be used, with steps reordered, added, or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this is not limited herein.

[0071] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetorheological processing device for adjusting the processing speed based on motor current, characterized in that, The device includes: A polishing assembly, including a driving motor and a polishing module, where the driving 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 where the element to be polished is located; A control unit, which controls the polishing module to perform fixed-point processing on the element to be polished at different processing speeds, and real-time collects the instantaneous current of the driving motor, and adjusts the processing speed according to the instantaneous current; The processing speed includes the polishing wheel speed of the polishing wheel in the polishing module and the liquid pump speed of the liquid pump.

2. The magnetorheological machining device for adjusting the machining speed based on the motor current according to claim 1, wherein In the control unit: Calculate the corresponding relationship between the processing speed and the set ideal motor current according to the first polishing data, where the first polishing data includes the first instantaneous current data of the driving motor at the set processing speed; And it is used to real-time collect the second instantaneous current data, and compare the second instantaneous current data with the ideal motor current corresponding to the current processing speed in the corresponding relationship. If the difference between the two exceeds the preset error range, then control the polishing assembly to adjust the current processing speed so that the difference between the second instantaneous current data collected after the processing speed is adjusted and the ideal motor current is within the preset error range; The second instantaneous current data is the current data of the driving motor that the control unit real-time collects when the driving motor drives the polishing module to polish the element to be polished at a constant speed.

3. The magnetorheological machining device for adjusting the machining speed based on the motor current according to claim 1, wherein The polishing module includes: A magnetorheological mounting frame, connected to the moving assembly; the driving motor is arranged on the magnetorheological mounting frame, and the polishing wheel is arranged on the magnetorheological mounting frame; the driving motor drives the polishing wheel to rotate and adjusts the polishing wheel speed; Magnets, arranged on the magnetorheological mounting frame and close to the working point of the polishing wheel; Magnetorheological medium, connected to the polishing wheel, and the magnetorheological medium is used to enter the magnetic field working area of the magnet under the drive of the polishing wheel to form a magnetorheological ribbon, and the size parameters of the magnetorheological ribbon change with the polishing gap and the magnetic field strength, and are used to polish the element to be polished; Nozzles, arranged on the magnetorheological mounting frame through nozzle mounting seats, and the liquid pump transports the magnetorheological fluid medium to the nozzles, and the nozzles supply the magnetorheological fluid medium to the polishing wheel.

4. A magnetorheological processing method for adjusting the rotational speed of a polishing wheel based on motor current, according to the magnetorheological processing device for adjusting the processing rotational speed based on motor current described in any one of claims 1 to 3, characterized in that, The method includes the following steps: The moving assembly drives the polishing assembly to move to the position where the test optical element is located, and makes the polishing module contact the test optical element; The control unit calculates the correspondence between the polishing wheel rotation speed and the ideal motor current according to the first polishing data, where the first polishing data includes the real-time current data of the drive motor collected at different set polishing wheel rotation speeds; and the 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 polishing wheel rotation speed in the correspondence. If the difference between the two exceeds the preset error range, the drive motor is controlled to adjust the current polishing wheel rotation speed 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 drive motor collected in real time by the control unit when the drive motor drives the polishing module to polish the element to be polished at a constant rotation speed.

5. The magnetorheological processing method for adjusting the rotational speed of a polishing wheel based on motor current according to claim 4, wherein If the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the polishing wheel rotation speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest time for switching between two adjacent machining trajectory points on the element to be polished is denoted as t3; The method includes: Judge whether the relationship among t1, t2, and t3 satisfies the formula: ； If not, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and the sampling frequency is 1 / t1.

6. The magnetorheological processing method for adjusting the rotational speed of the polishing wheel based on the motor current according to claim 5, wherein, The maximum change adjustment amount is the adjustment amplitude corresponding to adjusting the set ideal polishing wheel rotation speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔV 1max ; t2 = ΔV 1max / dV1, t3 = ΔL / V max , where dV1 is the fastest adjustment rate of the rotation speed of the polishing wheel, V max is the maximum moving speed of the moving component, and ΔL represents the distance between two adjacent machining track points on the element to be polished.

7. The magnetorheological machining method for adjusting the rotational speed of a polishing wheel based on motor current according to claim 5, characterized in that The method further includes: When the moving component drives the polishing module to move from the first trajectory point to the second trajectory point, filter the second instantaneous current data collected by the control unit during the movement, and compare the filtered second instantaneous current data with the ideal motor current at the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the movement is denoted as a, then a satisfies the following formula: 。 8. The magnetorheological processing method for adjusting the polishing wheel rotation speed based on the motor current according to claim 4, characterized in that If the current polishing wheel rotation speed is V i and the adjustment amplitude to the upper threshold value of the preset error range is denoted as +ΔV 1max , the current output value of the corresponding drive motor is A0 + ΔA max , A0 represents the ideal motor current, and ΔA max represents the corresponding current adjustment amplitude; The adjustment range from the rotational speed of the polishing wheel to the lower threshold of the preset error range is denoted as -ΔV 1max , and the current output value of the corresponding drive motor is A0 - ΔA max ; Controlling the driving motor to adjust the current rotational speed V of the polishing wheel i The adjustment includes: If the current second instantaneous current data A i does not exceed the allowable change range [A ′ , A ′′ , there is no need to control the driving motor to adjust the current polishing wheel speed V i ; If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the drive motor to adjust the current polishing wheel speed V va according to the following formula: i Adjustment is made according to the following formula: ； If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current polishing wheel speed V i is adjusted to V0 ± ΔV 1max , where V0 represents the initially set polishing wheel speed; so that the second instantaneous current data A corresponding to the adjusted polishing wheel speed i returns to the allowable change range [A ′ , A ′′ .

9. A magnetorheological processing method for adjusting the rotational speed of a liquid pump based on motor current, according to the magnetorheological processing device for adjusting the processing rotational speed based on motor current described in any one of claims 1 to 3, characterized in that, The method includes the following steps: The moving component drives the polishing component to move to the position where the test optical element is located, and makes the polishing module contact the test optical element; The control unit calculates the correspondence between the liquid pump rotation speed and the ideal motor current according to the first polishing data, where the first polishing data includes the real-time current data of the drive motor collected at different set liquid pump rotation speeds; and the 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 liquid pump rotation speed in the correspondence. If the difference between the two exceeds the preset error range, the polishing module is controlled to adjust the current liquid pump rotation speed 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 drive motor collected in real time by the control unit when the drive motor drives the polishing module to polish the element to be polished at a constant rotation speed.

10. The magnetorheological processing method for adjusting the rotational speed of a liquid pump based on motor current according to claim 9, characterized in that, If the sampling period for collecting the second instantaneous current data is denoted as t1, the shortest time required for the liquid pump speed to complete the set maximum change adjustment amount is denoted as t2, and the shortest switching time between two adjacent machining trajectory points on the element to be polished is denoted as t3; The method includes: Determine whether the relationship among t1, t2, and t3 satisfies the following formula: ； If not satisfied, adjust the sampling frequency of the control unit for collecting the second instantaneous current data until the above formula is satisfied, and set the sampling frequency to 1 / t1.

11. The magnetorheological processing method for adjusting the rotational speed of a liquid pump based on motor current according to claim 10, characterized in that, The maximum change adjustment amount is the adjustment amplitude corresponding to adjusting the set ideal liquid pump speed to the upper threshold or the lower threshold of the preset error range, denoted as ΔSV max ; t2 = ΔSV max / SV max ,t3 = ΔL / V max ,wherein, SV max is the maximum rotational speed adjustment rate of the liquid pump, V max is the maximum moving speed of the moving component, and ΔL represents the distance between two adjacent points to be machined on the element to be polished.

12. The magnetorheological processing method for adjusting the rotational speed of a liquid pump based on motor current according to claim 10, wherein, The method further includes: When the moving component drives the polishing module to move from the first trajectory point to the second trajectory point, perform filtering processing on the second instantaneous current data collected by the control unit during the movement, and compare the filtered second instantaneous current data with the ideal motor current at the current polishing gap; If the number of the second instantaneous current data collected by the control unit during the movement is denoted as a, then a satisfies the following formula: 。 13. The magnetorheological processing method for adjusting the liquid pump speed based on the motor current according to claim 9, wherein If the current liquid pump speed is SV i The adjustment amplitude to the upper threshold value of the preset error range is denoted as +ΔSV max , and the current output value of the corresponding drive motor is A0 + ΔA max , A0 represents the ideal motor current, and ΔA max represents the corresponding current adjustment amplitude; From the current liquid pump rotation speed SV i The adjustment amplitude to the lower threshold of the preset error range is denoted as -ΔSV max , and the current output value of the corresponding drive motor is A0 - ΔA max ; Controlling the polishing module to adjust the current liquid pump rotation speed SV i The adjustment includes: If the current second instantaneous current data A i does not exceed the allowable change range [A ′ , A ′′ , there is no need to control the polishing module to adjust the current liquid pump speed SV i ; If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | < |A0 ± ΔA max |, then control the polishing module to combine the corresponding relationship F sa to adjust the current liquid pump speed SV i according to the following formula: ； If the second instantaneous current data A of the current drive motor i exceeds the allowable change range [A ′ , A ′′ and |A i | ≥ |A0 ± ΔA max |, then the current liquid pump speed SV i is adjusted to SV0 ± ΔSV max , where SV0 represents the initially set liquid pump speed; so that the second instantaneous current data A corresponding to the adjusted liquid pump speed i returns to the allowable change range [A ′ , A ′′ .

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