Magnetorheological polishing equipment and polishing method based on electromagnetic flowmeter sensing

Abstract

The present invention relates to the field of magnetorheological polishing technology, and more particularly to a magnetorheological polishing device and polishing method based on electromagnetic flowmeter sensing. The device monitors changes in magnetorheological fluid flow during polishing using an electromagnetic flowmeter. By controlling the speed of a liquid pump and the position of a magnet or polishing wheel, two-stage regulation of magnetorheological fluid flow fluctuations (coarse and fine) is achieved. This ensures that magnetorheological fluid flow fluctuations at each polishing point meet high-precision polishing requirements, ensuring a constant removal function during the polishing process. This device does not require an additional follower device, resulting in lower equipment costs, smaller flow variations, and more stable magnetorheological fluid flow fluctuations.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetorheological polishing, and in particular to a magnetorheological polishing device based on electromagnetic flowmeter sensing and a polishing method thereof. Background Art

[0002] Magnetorheological finishing (MRF) is an advanced optical manufacturing technology developed in recent years. It offers numerous advantages, including a 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 techniques primarily integrate MRF modules onto CNC machine tools. The MRF module's supply system primarily utilizes a centrifugal pump as its source. However, using a centrifugal pump as the supply source presents a significant problem: as the nozzle of the MRF module processes the curved surface of an optical component, it moves up and down within the work area along with the tool end of the industrial robot. While the centrifugal pump maintains a constant position, the pressure between the pump and nozzle fluctuates, causing the previously stable MRF to change. This, in turn, alters the removal function and affects the final machining accuracy.

[0003] To address this problem, the currently commonly used method is to add a follower device to keep the vertical distance between the centrifugal pump and the nozzle outlet unchanged. However, this method requires an additional follower device with higher motion performance to keep the vertical distance between the centrifugal pump and the nozzle outlet unchanged at all times. Some solutions even place the follower device on the Z-axis of the CNC machine tool, which undoubtedly increases the motion load and equipment cost of the motion mechanism and reduces the motion performance of the equipment. In addition, the follower device cannot strictly ensure that the vertical distance between the centrifugal pump and the nozzle outlet is constant. Therefore, the height difference between the centrifugal pump and the nozzle often changes at all times, affecting the stability of the magnetorheological fluid in the magnetorheological supply system, causing the removal function to change during the processing, affecting the processing results, and increasing the equipment cost. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetorheological polishing device based on electromagnetic flowmeter sensing and a polishing method thereof, so as to solve the problem in the prior art that even if a follow-up device is added, the removal function cannot be kept constant during the machining process.

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

[0006] A magnetorheological polishing device based on electromagnetic flowmeter sensing, comprising:

[0007] a polishing platform on which the element to be polished and the test polishing element are arranged;

[0008] A polishing assembly includes an industrial robot and a magnetorheological polishing module. The industrial robot is used to drive the magnetorheological polishing module to move to the location of a test polishing element or a component to be polished. The magnetorheological polishing module is used to polish the component to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, a magnet, and a liquid pump. The magnetorheological mounting frame is installed on the tool end of the industrial robot. The polishing wheel, the nozzle, and the magnet are respectively installed on the magnetorheological mounting frame. The liquid pump is arranged on the industrial robot or on one side of the industrial robot. The liquid pump is used to pump magnetorheological fluid into the nozzle. The nozzle is used to spray magnetorheological fluid onto the polishing wheel. The magnet is used to change the stiffness of the magnetorheological fluid. The polishing wheel is used to polish the test polishing element or the component to be polished.

[0009] An electromagnetic flowmeter is installed on the industrial robot to monitor the flow rate of the magnetorheological fluid at the nozzle outlet;

[0010] The laser tracker is set on one side of the polishing platform and is used in conjunction with the target ball to measure the vertical distance between the nozzle and the liquid pump;

[0011] The computer is used to establish a first conversion relationship between the vertical distance and the liquid pump rotation speed, a second conversion relationship between the vertical distance and the magnetorheological fluid flow rate, and a third conversion relationship between the magnet position or the polishing wheel position and the magnetorheological fluid flow rate based on the magnetorheological fluid flow rate monitored by the electromagnetic flowmeter, and the computer is used to adjust the liquid pump rotation speed, the industrial robot posture, and the magnet position or the polishing wheel position based on the first conversion relationship to the third conversion relationship to maintain a constant removal function for each polishing point of the element to be polished.

[0012] Furthermore, the magnetorheological polishing module also includes two sets of position adjustment devices, each set of position adjustment devices includes a supporting frame, a ball screw stepper motor and a connecting plate. The ball screw stepper motor is vertically mounted on the magnetorheological mounting frame through the supporting frame. The nut of the ball screw stepper motor is fixedly connected to the connecting plate, and the magnet and polishing wheel are respectively connected to the corresponding connecting plates.

[0013] Furthermore, the magnetorheological polishing module further includes a polishing wheel drive device, which includes a driving motor, a motor connecting plate, a driving wheel, a driven wheel and a synchronous belt. The driving motor is installed on the connecting plate, a bearing seat is installed on the connecting plate, a bearing is installed in the bearing seat, the bearing is connected to the polishing wheel, the driven wheel is mounted on the bearing, the driving wheel is mounted on the output end of the driving motor, and the synchronous belt is tensioned on the driven wheel and the driving wheel.

[0014] A magnetorheological polishing method based on industrial robot posture adjustment is implemented using the above-mentioned magnetorheological polishing equipment based on electromagnetic flowmeter sensing, comprising the following steps:

[0015] S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed;

[0016] And at each vertical distance, different polishing gaps are set, and the magnetorheological fluid flow corresponding to different polishing gaps at each vertical distance is measured by an electromagnetic flowmeter to obtain discrete data of the polishing gap and the magnetorheological fluid flow at each vertical distance. The second conversion relationship between the polishing gap and the corresponding magnetorheological fluid flow at each vertical distance is obtained by data fitting. The second conversion relationship can be expressed as ,in, Indicates the polishing gap at each vertical distance, Indicates the magnetorheological fluid flow rate corresponding to the polishing gap at each vertical distance, It shows the conversion relationship between the polishing gap and the magnetorheological fluid flow rate at various vertical distances;

[0017] S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, represents the vertical distance of the i-th polishing point;

[0018] S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the polishing gap of the polishing point unchanged. If it exceeds, adjust the posture of the industrial robot according to the adjustment amount of the polishing gap to change the polishing gap of the polishing point until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

[0019] Furthermore, when polishing each polishing point of the polishing element, a dwell time is set for each polishing point, which specifically includes the following steps:

[0020] S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot;

[0021] S220: driving the industrial robot to move toward the polishing platform so that the lowest point of the polishing wheel just contacts the polishing platform, placing the target ball at the nozzle outlet, and measuring the Z-axis coordinate Z4 of the target ball at this time;

[0022] S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is The time required for the magnetorheological fluid sprayed from the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

[0023] Furthermore, when the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

[0024] Furthermore, in step S3, the maximum adjustment amount of the Z-axis control amount of the industrial robot is set in the computer to ;as well as,

[0025] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Keep the polishing gap of the polishing point unchanged;

[0026] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the current industrial robot according to the following formula :

[0027] ;

[0028] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the industrial robot according to the following formula :

[0029] ;

[0030] in, Indicates the initial Z-axis coordinate of the industrial robot.

[0031] A magnetorheological polishing method based on magnet position or polishing wheel position adjustment is implemented using the above-mentioned magnetorheological polishing device based on electromagnetic flowmeter sensing, comprising the following steps:

[0032] S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed;

[0033] And at each vertical distance, a different polishing gap is set, a different magnet position or polishing wheel position is set at each polishing gap, and the magnetorheological fluid flow rate corresponding to the magnet or polishing wheel at different positions in each polishing gap is measured by an electromagnetic flowmeter to obtain discrete data of the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap. The third conversion relationship between the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap is obtained by data fitting. The third conversion relationship can be expressed as: ,in, Indicates the magnet position or polishing wheel position, Indicates the magnetorheological fluid flow rate corresponding to the different positions of the magnet or polishing wheel in each polishing gap. Indicates the conversion relationship between the magnet or polishing wheel at different positions and the magnetorheological fluid flow rate at each vertical distance;

[0034] S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, represents the vertical distance of the i-th polishing point;

[0035] S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the magnet position or polishing wheel position of the polishing point unchanged. If it exceeds, the position adjustment device adjusts the magnet position or polishing wheel position according to the adjustment amount of the magnet position or polishing wheel position until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

[0036] Furthermore, when polishing each polishing point of the polishing element, a dwell time is set for each polishing point, which specifically includes the following steps:

[0037] S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot;

[0038] S220: driving the industrial robot to move toward the polishing platform so that the lowest point of the polishing wheel just contacts the polishing platform, placing the target ball at the nozzle outlet, and measuring the Z-axis coordinate Z4 of the target ball at this time;

[0039] S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is The time required for the magnetorheological fluid sprayed from the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

[0040] Furthermore, when the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

[0041] Furthermore, in step S3, the maximum adjustment amount of the magnet position or the polishing wheel position is set in the computer as ;as well as,

[0042] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Inside, keep the magnet position or polishing wheel position unchanged;

[0043] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , then adjust the current magnet position or polishing wheel position according to the following formula:

[0044] ;

[0045] in, Indicates the current magnet position or polishing wheel position;

[0046] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , adjust the magnet position or polishing wheel position according to the following formula:

[0047] ;

[0048] in, Indicates the initial position of the magnet or polishing wheel.

[0049] Compared to existing technologies, this invention uses an electromagnetic flowmeter to measure changes in the magnetorheological fluid flow rate during the polishing process. By controlling the liquid pump speed and the position of the magnet or polishing wheel, it achieves two-stage regulation of the magnetorheological fluid flow fluctuations, both coarse and fine. This ensures that the magnetorheological fluid flow fluctuations at each polishing point meet the requirements of high-precision polishing, ensuring a constant removal function during the polishing process. This invention eliminates the need for additional follower devices, resulting in lower equipment costs, minimal flow rate variations, and more stable magnetorheological fluid flow fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic structural diagram of a magnetorheological polishing device based on electromagnetic flowmeter sensing according to an embodiment of the present invention at one viewing angle;

[0051] Figure 2 A schematic structural diagram of the magnetorheological polishing device based on electromagnetic flowmeter sensing according to an embodiment of the present invention from another perspective;

[0052] Figure 3 A schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention at one viewing angle;

[0053] Figure 4 A schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention from another perspective;

[0054] Figure 5 This is a structural diagram of the position adjustment device described in an embodiment of the present invention.

[0055] Figure numerals: polishing platform 1, element to be polished 101, test polishing element 102, industrial robot 201, magnetorheological mounting frame 202, polishing wheel 203, magnet 204, nozzle 205, liquid pump 206, support bracket 207, ball screw stepper motor 208, connecting plate 209, drive motor 210, active wheel 211, driven wheel 212, synchronous belt 213, screw 214, guide rail 215, slider 216, nut 217, position adjustment device 218, mounting bracket 219, electromagnetic flowmeter 3, laser tracker 4, target ball 401, computer 5. DETAILED DESCRIPTION

[0056] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, identical modules are denoted by identical reference numerals. In the case of identical reference numerals, their names and functions are also identical. Therefore, their detailed description will not be repeated.

[0057] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0058] In the first aspect, this embodiment provides a magnetorheological polishing device based on electromagnetic flowmeter sensing, the structure of the device is as follows: Figure 1-Figure 5 As shown, including:

[0059] A polishing platform 1, on which a to-be-polished element 101 and a test polishing element 102 are arranged;

[0060] The polishing assembly includes an industrial robot 201 and a magnetorheological polishing module. The industrial robot 201 is used to drive the magnetorheological polishing module to move to the location of the test polishing element 102 or to drive the magnetorheological polishing module to move to the location of the element to be polished 101; the magnetorheological polishing module is used to polish the element to be polished 101 or the test polishing element 102. The magnetorheological polishing module includes a magnetorheological mounting frame 202, a polishing wheel 203, a magnet 204, a nozzle 205, a liquid pump 206, two sets of position adjustment devices 218 and a set of polishing wheel driving devices. The magnetorheological mounting frame 202 is installed on the tool end of the industrial robot 201, and the polishing wheel driving device is installed on the magnetorheological mounting frame 202 to drive the polishing wheel 203 to rotate to polish the element to be polished. 101 or the test polishing element 102 is polished; the nozzle 205 is mounted on the magnetorheological mounting frame 202 and is used to spray magnetorheological fluid onto the polishing wheel 203; the liquid pump 206 is mounted on the industrial robot 201 or on a mounting bracket 219 on one side of the industrial robot 201, and the liquid pump 206 is connected to the nozzle 205 through a pipeline and is used to pump magnetorheological fluid into the nozzle 205. The liquid pump 206 uses a DFLD vertical multi-stage pump from Shanghai Dongfang Pump Industry Co., Ltd.; two sets of position adjustment devices 218 are respectively mounted on the magnetorheological mounting frame 202, one set of position adjustment devices 218 is used to adjust the position of the magnet 204, which is used to change the stiffness of the magnetorheological fluid; the other set of position adjustment devices 218 is used to adjust the position of the polishing wheel 203;

[0061] An electromagnetic flowmeter 3, which is provided on the industrial robot 201 and is used to monitor the flow rate of the magnetorheological fluid at the outlet of the nozzle 205;

[0062] The laser tracker 4 is provided on one side of the polishing platform 1 and is used in conjunction with the target ball 401 to measure the vertical distance between the nozzle 205 and the liquid pump 206 (hereinafter referred to as the vertical distance);

[0063] Computer 5 is used to establish a first conversion relationship between the vertical distance and the rotation speed of the liquid pump 206, a second conversion relationship between the vertical distance and the magnetorheological fluid flow rate, and a third conversion relationship between the position of the magnet 204 or the polishing wheel 203 and the magnetorheological fluid flow rate based on the magnetorheological fluid flow rate monitored by the electromagnetic flowmeter 3. The computer 5 is also used to adjust the rotation speed of the liquid pump 206, the posture of the industrial robot 201, and the position of the magnet 204 or the polishing wheel 203 based on the first conversion relationship to the third conversion relationship to maintain a constant removal function for each polishing point of the element to be polished 101.

[0064] The two sets of position adjustment devices 218 have the same structure, both including a support and fixing frame 207, a ball screw stepper motor 208, and a connecting plate 209. The ball screw stepper motor 208 is vertically mounted on the magnetorheological mounting frame 202 through the support and fixing frame 207. The nut 217 of the ball screw stepper motor 208 is fixedly connected to the connecting plate 209. The magnet 204 and the polishing wheel 203 are respectively connected to the connecting plates 209 of the two sets of position adjustment devices. The ball screw stepper motors 208 of the two sets of position adjustment devices 218 drive the magnet 204 and the polishing wheel 203 to adjust their positions.

[0065] The polishing wheel drive device includes a driving motor 210, a driving wheel 211, a driven wheel 212 and a synchronous belt 213. The driving motor 210 is installed on the connecting plate 209. A bearing seat is installed on the connecting plate 209. A bearing is installed in the bearing seat. The bearing is connected to the polishing wheel 203. The driven wheel 212 is mounted on the bearing. The driving wheel 211 is mounted on the output end of the driving motor 210. The synchronous belt 213 is tensioned on the driven wheel 212 and the driving wheel 211. The polishing wheel 203 is driven to rotate by the driving motor 210. Please refer to the Chinese patent with publication date of July 12, 2024 and publication number CN118322074A.

[0066] In the embodiment of the present invention, to ensure that the polishing wheel 203 and the magnet 204 can stably move along the lead screw 214 of the ball screw stepper motor 208, a guide rail 215 is preferably installed on each side of the lead screw 214 on the support bracket 228, and the two guide rails 215 are parallel to the lead screw 214. Slide blocks 216 are slidably connected to the two guide rails 215. In this case, the connecting plate 209 is fixedly connected to the nut 217 and the two slide blocks 216. During the polishing process, the computer 5 sends a control signal to the ball screw stepper motor 208, which drives the connecting plate 209 to move linearly under the sliding cooperation of the guide rails 215 and the slide blocks 216.

[0067] It is worth noting that there is a strong magnetic phenomenon in the working area where the magnetorheological polishing module is located. The connections of various circuits need to avoid the working area to prevent the wires from being adsorbed on the magnetorheological polishing module and affecting normal operation.

[0068] In a second aspect, this embodiment further provides a magnetorheological polishing method based on industrial robot posture adjustment, which is implemented using the above-mentioned magnetorheological polishing device based on electromagnetic flowmeter sensing, and includes the following steps:

[0069] S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed;

[0070] And at each vertical distance, different polishing gaps are set, and the magnetorheological fluid flow corresponding to different polishing gaps at each vertical distance is measured by an electromagnetic flowmeter to obtain discrete data of the polishing gap and the magnetorheological fluid flow at each vertical distance. The second conversion relationship between the polishing gap and the corresponding magnetorheological fluid flow at each vertical distance is obtained by data fitting. The second conversion relationship can be expressed as ,in, Indicates the polishing gap at each vertical distance, Indicates the magnetorheological fluid flow rate corresponding to the polishing gap at each vertical distance, It shows the conversion relationship between the polishing gap and the magnetorheological fluid flow rate at various vertical distances.

[0071] The purpose of step S1 is to use the electromagnetic flowmeter to establish a first conversion relationship between the vertical distance and the liquid pump speed and a second conversion relationship between the polishing gap and the corresponding magnetorheological fluid flow rate at each vertical distance, as follows:

[0072] The theoretical initial value of the liquid pump speed and the theoretical initial value of the corresponding magnetorheological fluid flow rate are set for each polishing point of the test polishing element, the vertical distance between the liquid pump and the nozzle is set to at least 10 different values, and the magnetorheological fluid flow rate corresponding to different vertical distances is measured using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, the liquid pump speed is adjusted so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, and discrete data of the vertical distance and the liquid pump speed are obtained. The data are then fitted using Matlab's Polyfit command (a basic general command of Matlab software) to obtain a first transformation relationship;

[0073] At each vertical distance, the polishing gap is set to at least 10 sets of different values. The polishing gap and the corresponding magnetorheological fluid flow at different vertical distances are measured by an electromagnetic flowmeter to obtain discrete data of the polishing gap and the corresponding magnetorheological fluid flow at each vertical distance. The Polyfit command of Matlab (this command is a basic general command of Matlab software) is used to fit the data to obtain the second transformation relationship.

[0074] S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, Represents the vertical distance of the i-th polishing point.

[0075] The height change of the curved surface of the element to be polished reflects the change in the vertical distance between the liquid pump and the nozzle. According to the height of each polishing point on the curved surface of the element to be polished, the theoretical liquid pump speed of each polishing point is calculated using the first conversion relationship. The liquid pump speed is adjusted in real time according to the theoretical liquid pump speed of each polishing point, thereby completing the coarse adjustment of the magnetorheological fluid flow change of the entire curved surface with a large range of high and low movements when the polishing equipment is polishing the element to be polished.

[0076] Since the magnetorheological fluid measured by the electromagnetic flowmeter needs to be transported through the pipeline and driven by the polishing wheel to reach the working area of ​​the polishing wheel, the magnetorheological fluid at the current flow rate needs to wait for a period of time to reach the working area of ​​the polishing wheel. In order to ensure the adjustment of the removal function change at each polishing point, it is necessary to set the residence time of the polishing point. The specific setting method is as follows:

[0077] S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot.

[0078] S220: Drive the industrial robot to move toward the experimental table so that the lowest point of the polishing wheel just contacts the experimental table, place the target ball of the laser tracker at the nozzle outlet and measure the Z-axis coordinate Z4 of the target ball at this time.

[0079] S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is , To place the target ball on the nozzle to measure the Z-axis coordinate, the time required for the magnetorheological fluid sprayed by the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

[0080] When the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

[0081] S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the polishing gap of the polishing point unchanged. If it exceeds, adjust the posture of the industrial robot according to the adjustment amount of the polishing gap to change the polishing gap of the polishing point until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

[0082] Since optical component polishing is a variable-speed movement of the polishing equipment, the movement speed between two adjacent polishing points is often different. In the process from one polishing point to the next, there is often a mismatch between the theoretical polishing position and the actual polishing position, the magnetorheological fluid flow fluctuates, and the removal function changes.

[0083] Therefore, it is necessary to set the tolerance range of the magnetorheological fluid flow fluctuation during the polishing process in the computer. , is the lower limit of the magnetorheological fluid flow fluctuation, is the upper limit of magnetorheological fluid flow fluctuation.

[0084] During the polishing process, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is measured in real time by an electromagnetic flowmeter. If the measured actual magnetorheological fluid flow rate is If the actual magnetorheological fluid flow rate is within the range of If the magnetorheological fluid flow fluctuation is within the specified range, it does not meet the requirements of high-precision polishing. The measurement data needs to be output to the computer for processing, and the computer-processed data is sent to the industrial robot. Finally, the magnetorheological fluid flow change is regulated by adjusting the Z-axis coordinate of the industrial robot to maintain the removal function constant.

[0085] In order to ensure the safety of polishing, the maximum adjustment wheel of the Z-axis control amount of the industrial robot needs to be set in the computer. , place the component to be polished on the polishing platform and fix it, drive the polishing equipment to polish the component to be polished, and use the electromagnetic flowmeter to measure the actual magnetorheological fluid flow at the nozzle outlet .

[0086] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Keep the polishing gap of the polishing point unchanged;

[0087] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the current industrial robot according to the following formula :

[0088] ;

[0089] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the industrial robot according to the following formula :

[0090] ;

[0091] in, Indicates the initial Z-axis coordinate of the industrial robot.

[0092] By adjusting the posture of the industrial robot (i.e., Z-axis coordinate adjustment), the polishing gap between the polishing wheel and the component to be polished is changed, and precise adjustment of the magnetorheological fluid flow rate in a small range is completed, so that the magnetorheological fluid flow fluctuation at each polishing point meets the requirements of high-precision polishing, ensuring the constancy of the removal function during the polishing process.

[0093] Compared with the current mainstream real-time control scheme of flow change of magnetorheological fluid supply system based on follow-up device, the present invention uses electromagnetic flowmeter to measure the flow change of polishing equipment during the polishing process and realizes coarse and fine two-stage adjustment of flow fluctuation by controlling the speed of liquid pump and the posture of industrial robot, thereby realizing real-time control of removal function change. No additional follow-up device is required, the equipment cost is lower, the flow change is small, and the magnetorheological fluid flow fluctuation is more stable.

[0094] In a third aspect, this embodiment further provides a magnetorheological polishing method based on magnet position or polishing wheel position adjustment, which is implemented using the above-mentioned magnetorheological polishing device based on electromagnetic flowmeter sensing, and includes the following steps:

[0095] S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed;

[0096] And at each vertical distance, a different polishing gap is set, a different magnet position or polishing wheel position is set at each polishing gap, and the magnetorheological fluid flow rate corresponding to the magnet or polishing wheel at different positions in each polishing gap is measured by an electromagnetic flowmeter to obtain discrete data of the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap. The third conversion relationship between the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap is obtained by data fitting. The third conversion relationship can be expressed as: ,in, Indicates the magnet position or polishing wheel position, Indicates the magnetorheological fluid flow rate corresponding to the different positions of the magnet or polishing wheel in each polishing gap. It represents the conversion relationship between the magnet or polishing wheel at different positions and the magnetorheological fluid flow rate at each vertical distance.

[0097] Under different polishing gaps and vertical distances, the removal function is kept constant by changing the position of the magnet or polishing wheel, and then various data are collected to obtain the third conversion relationship between the different positions of the magnet or polishing wheel and the corresponding magnetorheological fluid flow rate under each polishing gap, which facilitates the subsequent adjustment of various parameters.

[0098] Different polishing gaps mean that the relative distance between the polishing wheel and the magnet remains unchanged, while the distance between the entire magnetorheological polishing module and the polishing workpiece changes.

[0099] The purpose of step S1 is to use the electromagnetic flowmeter to establish a first conversion relationship between the vertical distance and the liquid pump speed, and a third conversion relationship between the different positions of the magnet or polishing wheel in each polishing gap and the corresponding magnetorheological fluid flow rate, as follows:

[0100] The theoretical initial value of the liquid pump speed and the theoretical initial value of the corresponding magnetorheological fluid flow rate are set for each polishing point of the test polishing element, the vertical distance between the liquid pump and the nozzle is set to at least 10 different values, and the magnetorheological fluid flow rate corresponding to different vertical distances is measured using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, the liquid pump speed is adjusted so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, and discrete data of the vertical distance and the liquid pump speed are obtained. The data are then fitted using Matlab's Polyfit command (a basic general command of Matlab software) to obtain a first transformation relationship;

[0101] At each polishing gap, the magnet position or the polishing wheel position is set to at least 10 different values. The magnet position and the corresponding magnetorheological fluid flow rate or the polishing wheel position and the corresponding magnetorheological fluid flow rate at different polishing gaps are measured by an electromagnetic flowmeter to obtain discrete data of the magnet position and the corresponding magnetorheological fluid flow rate or the polishing wheel position and the corresponding magnetorheological fluid flow rate at each polishing gap. The Polyfit command of Matlab (this command is a basic general command of Matlab software) is used to perform data fitting to obtain a third transformation relationship.

[0102] S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, Represents the vertical distance of the i-th polishing point.

[0103] The height change of the curved surface of the element to be polished reflects the change of the vertical distance between the liquid pump and the nozzle. According to the height of each polishing point on the curved surface of the element to be polished, the theoretical liquid pump speed of each polishing point is calculated using the first conversion relationship. The liquid pump speed is adjusted in real time according to the theoretical liquid pump speed of each polishing point, completing the coarse adjustment of the large-scale removal function flow change of the height movement of the entire curved surface when the polishing equipment polishes the element to be polished.

[0104] Since the magnetorheological fluid measured by the electromagnetic flowmeter needs to be transported through the pipeline and driven by the polishing wheel to reach the working area of ​​the polishing wheel, the magnetorheological fluid at the current flow rate needs to wait for a period of time to reach the working area of ​​the polishing wheel. In order to ensure the adjustment of the removal function change at each polishing point, it is necessary to set the residence time of the polishing point. The specific setting method is as follows:

[0105] S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot.

[0106] S220: Drive the industrial robot to move toward the experimental table so that the lowest point of the polishing wheel just contacts the experimental table, place the target ball of the laser tracker at the nozzle outlet and measure the Z-axis coordinate Z4 of the target ball at this time.

[0107] S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is The time required for the magnetorheological fluid sprayed from the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

[0108] When the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

[0109] S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the magnet position or polishing wheel position of the polishing point unchanged. If it exceeds, the position adjustment device adjusts the magnet position or polishing wheel position according to the adjustment amount of the magnet position or polishing wheel position until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

[0110] Since optical component polishing is a variable-speed movement of the polishing equipment, the movement speed between two adjacent polishing points is often different. In the process from one polishing point to the next, there is often a mismatch between the theoretical polishing position and the actual polishing position, the magnetorheological fluid flow fluctuates, and the removal function changes.

[0111] Therefore, it is necessary to set the tolerance range of the magnetorheological fluid flow fluctuation during the polishing process in the computer. , is the lower limit of the magnetorheological fluid flow fluctuation, is the upper limit of magnetorheological fluid flow fluctuation.

[0112] During the polishing process, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is measured in real time by an electromagnetic flowmeter. If the measured actual magnetorheological fluid flow rate is If the actual magnetorheological fluid flow rate is within the range of If the magnetorheological fluid flow fluctuation is within the range, the magnetorheological fluid flow fluctuation does not meet the requirements of high-precision polishing. The measurement data needs to be output to the computer for processing, and the computer-processed data is sent to the position adjustment device to adjust the magnet position or the polishing wheel position to regulate the magnetorheological fluid flow change and maintain the removal function constant.

[0113] In order to ensure the safety of polishing, the maximum adjustment of the polishing wheel position or the magnet position needs to be set in the computer. , place the component to be polished on the polishing platform and fix it, drive the polishing equipment to polish the component to be polished, and use the electromagnetic flowmeter to measure the actual magnetorheological fluid flow at the nozzle outlet .

[0114] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Inside, keep the magnet position or polishing wheel position unchanged;

[0115] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , then adjust the current magnet position or polishing wheel position according to the following formula:

[0116] ;

[0117] in, Indicates the current magnet position or polishing wheel position;

[0118] If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , adjust the magnet position or polishing wheel position according to the following formula:

[0119] ;

[0120] in, Indicates the initial position of the magnet or polishing wheel.

[0121] By adjusting the position of the polishing wheel or magnet, the magnetorheological fluid flow rate can be precisely adjusted within a small range, so that the magnetorheological fluid flow fluctuation at each polishing point meets the requirements of high-precision polishing, ensuring the constancy of the removal function during the polishing process.

[0122] Compared with the current mainstream real-time control scheme of flow change of magnetorheological fluid supply system based on follow-up device, the present invention uses electromagnetic flowmeter to measure the flow change of polishing equipment during the polishing process and realizes coarse and fine two-stage adjustment of flow fluctuation by controlling the speed of liquid pump and controlling the position of magnet or polishing wheel, thereby realizing real-time control of removal function change. No additional follow-up device is required, the equipment cost is lower, the flow change is small, and the magnetorheological fluid flow fluctuation is more stable.

[0123] 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.

[0124] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A magnetorheological polishing device based on electromagnetic flowmeter sensing, characterized in that: include: a polishing platform on which the element to be polished and the test polishing element are arranged; A polishing assembly includes an industrial robot and a magnetorheological polishing module. The industrial robot is used to drive the magnetorheological polishing module to move to the location of a test polishing element or a component to be polished. The magnetorheological polishing module is used to polish the component to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, a magnet, and a liquid pump. The magnetorheological mounting frame is installed on the tool end of the industrial robot. The polishing wheel, the nozzle, and the magnet are respectively installed on the magnetorheological mounting frame. The liquid pump is arranged on the industrial robot or on one side of the industrial robot. The liquid pump is used to pump magnetorheological fluid into the nozzle. The nozzle is used to spray magnetorheological fluid onto the polishing wheel. The magnet is used to change the stiffness of the magnetorheological fluid. The polishing wheel is used to polish the test polishing element or the component to be polished. An electromagnetic flowmeter is installed on the industrial robot to monitor the flow rate of the magnetorheological fluid at the nozzle outlet; The laser tracker is set on one side of the polishing platform and is used in conjunction with the target ball to measure the vertical distance between the nozzle and the liquid pump; The computer is used to establish a first conversion relationship between the vertical distance and the liquid pump rotation speed, a second conversion relationship between the vertical distance and the magnetorheological fluid flow rate, and a third conversion relationship between the magnet position or the polishing wheel position and the magnetorheological fluid flow rate based on the magnetorheological fluid flow rate monitored by the electromagnetic flowmeter, and the computer is used to adjust the liquid pump rotation speed, the industrial robot posture, and the magnet position or the polishing wheel position based on the first conversion relationship to the third conversion relationship to maintain a constant removal function for each polishing point of the element to be polished.

2. The magnetorheological polishing equipment based on electromagnetic flowmeter sensing according to claim 1 is characterized in that: The magnetorheological polishing module also includes two sets of position adjustment devices. Each set of position adjustment devices includes a support and fixing frame, a ball screw stepper motor and a connecting plate. The ball screw stepper motor is vertically mounted on the magnetorheological mounting frame through the support and fixing frame. The nut of the ball screw stepper motor is fixedly connected to the connecting plate, and the magnet and polishing wheel are respectively connected to the corresponding connecting plates.

3. The magnetorheological polishing equipment based on electromagnetic flowmeter sensing according to claim 1 is characterized in that: The magnetorheological polishing module further includes a polishing wheel drive device, which includes a driving motor, a motor connecting plate, a driving wheel, a driven wheel and a synchronous belt. The driving motor is installed on the connecting plate, a bearing seat is installed on the connecting plate, a bearing is installed in the bearing seat, the bearing is connected to the polishing wheel, the driven wheel is mounted on the bearing, the driving wheel is mounted on the output end of the driving motor, and the synchronous belt is tensioned on the driven wheel and the driving wheel.

4. A magnetorheological polishing method based on industrial robot posture adjustment, implemented using the magnetorheological polishing device based on electromagnetic flowmeter sensing according to claim 1, characterized in that: The steps include: S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed; And at each vertical distance, different polishing gaps are set, and the magnetorheological fluid flow corresponding to different polishing gaps at each vertical distance is measured by an electromagnetic flowmeter to obtain discrete data of the polishing gap and the magnetorheological fluid flow at each vertical distance. The second conversion relationship between the polishing gap and the corresponding magnetorheological fluid flow at each vertical distance is obtained by data fitting. The second conversion relationship can be expressed as ,in, Indicates the polishing gap at each vertical distance, Indicates the magnetorheological fluid flow rate corresponding to the polishing gap at each vertical distance, It shows the conversion relationship between the polishing gap and the magnetorheological fluid flow rate at various vertical distances; S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, represents the vertical distance of the i-th polishing point; S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the polishing gap of the polishing point unchanged. If it exceeds, adjust the posture of the industrial robot according to the adjustment amount of the polishing gap to change the polishing gap of the polishing point until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

5. The magnetorheological polishing method based on industrial robot posture adjustment according to claim 4 is characterized in that: When polishing each polishing point of the polishing element, the dwell time is set for each polishing point, which specifically includes the following steps: S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot; S220: driving the industrial robot to move toward the polishing platform so that the lowest point of the polishing wheel just contacts the polishing platform, placing the target ball at the nozzle outlet, and measuring the Z-axis coordinate Z4 of the target ball at this time; S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is The time required for the magnetorheological fluid sprayed from the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

6. The magnetorheological polishing method based on industrial robot posture adjustment according to claim 5 is characterized in that: When the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

7. The magnetorheological polishing method based on industrial robot posture adjustment according to claim 4 is characterized in that: In step S3, the maximum adjustment amount of the Z-axis control amount of the industrial robot is set in the computer to ; as well as, If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Keep the polishing gap of the polishing point unchanged; If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the current industrial robot according to the following formula : ； If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The Z-axis coordinate adjustment value of the current industrial robot , then adjust the Z-axis coordinate of the industrial robot according to the following formula : ； in, Indicates the initial Z-axis coordinate of the industrial robot.

8. A magnetorheological polishing method based on magnet position or polishing wheel position adjustment, implemented using the magnetorheological polishing device based on electromagnetic flowmeter sensing according to claim 2, characterized in that: The steps include: S1: Set the theoretical initial value of the liquid pump speed and the corresponding magnetorheological fluid flow rate at each polishing point of the test polishing element, polish the test polishing element, change the vertical distance between the liquid pump and the nozzle, and measure the magnetorheological fluid flow rate corresponding to different vertical distances using an electromagnetic flowmeter. If the magnetorheological fluid flow rate is different from the set theoretical initial value, adjust the liquid pump speed so that the magnetorheological fluid flow rate is the same as the set theoretical initial value, obtain discrete data of the vertical distance and the liquid pump speed, and obtain the first conversion relationship between the vertical distance and the liquid pump speed through data fitting; wherein, the first conversion relationship is expressed as , Indicates the liquid pump speed, Indicates the vertical distance, Indicates the conversion relationship between vertical distance and liquid pump speed; And at each vertical distance, a different polishing gap is set, a different magnet position or polishing wheel position is set at each polishing gap, and the magnetorheological fluid flow rate corresponding to the magnet or polishing wheel at different positions in each polishing gap is measured by an electromagnetic flowmeter to obtain discrete data of the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap. The third conversion relationship between the magnet or polishing wheel at different positions and the corresponding magnetorheological fluid flow rate in each polishing gap is obtained by data fitting. The third conversion relationship can be expressed as: ,in, Indicates the magnet position or polishing wheel position, Indicates the magnetorheological fluid flow rate corresponding to the different positions of the magnet or polishing wheel in each polishing gap. Indicates the conversion relationship between the magnet or polishing wheel at different positions and the magnetorheological fluid flow rate at each vertical distance; S2: According to the height change of the curved surface of the component to be polished, the liquid pump speed change is calculated based on the first conversion relationship to obtain the theoretical liquid pump speed corresponding to each polishing point of the component to be polished. The component to be polished is polished according to the theoretical liquid pump speed of each polishing point. At the same time, the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to each polishing point is monitored in real time by an electromagnetic flowmeter and sent to the computer; wherein the theoretical liquid pump speed is expressed as ,in, Indicates the theoretical liquid pump speed of each polishing point, i=1, 2, 3...m, m represents the number of polishing points, represents the vertical distance of the i-th polishing point; S3: Set the flow fluctuation tolerance range in the computer, and determine whether the actual magnetorheological fluid flow at the nozzle outlet corresponding to each polishing point exceeds the set flow fluctuation tolerance range. If it does not exceed, keep the magnet position or polishing wheel position of the polishing point unchanged. If it exceeds, the position adjustment device adjusts the magnet position or polishing wheel position according to the adjustment amount of the magnet position or polishing wheel position until the actual magnetorheological fluid flow does not exceed the flow fluctuation tolerance range, so as to maintain the removal function of each polishing point constant.

9. The magnetorheological polishing method based on magnet position or polishing wheel position adjustment according to claim 8, characterized in that: When polishing each polishing point of the polishing element, the dwell time is set for each polishing point, which specifically includes the following steps: S210: Establishing a measurement coordinate system of the laser tracker so that the measurement coordinate system is parallel to the tool coordinate system of the industrial robot; S220: driving the industrial robot to move toward the polishing platform so that the lowest point of the polishing wheel just contacts the polishing platform, placing the target ball at the nozzle outlet, and measuring the Z-axis coordinate Z4 of the target ball at this time; S230: Place the target ball on the polishing platform close to the lowest point of the polishing wheel and measure the Z-axis coordinate of the target ball at this time , then the vertical distance between the nozzle and the lowest point of the polishing wheel is The time required for the magnetorheological fluid sprayed from the magnetorheological supply system to reach the lowest point of the polishing wheel is ,in, Indicates the number of revolutions per second of the polishing wheel. Indicates the length of the pipe between the electromagnetic flowmeter and the nozzle. represents the magnetorheological fluid flow rate, Indicates the radius of the polishing wheel.

10. The magnetorheological polishing method based on magnet position or polishing wheel position adjustment according to claim 9, characterized in that: When the computer generates the polishing control program, if the dwell time of each polishing point is If the dwell time of a polishing point exists, the generated polishing control program is appropriate. , then extend the dwell time of the polishing point , regenerate the polishing control program so that the dwell time of each polishing point .

11. The magnetorheological polishing method based on magnet position or polishing wheel position adjustment according to claim 8, characterized in that: In step S3, the maximum adjustment amount of the magnet position or the polishing wheel position is set in the computer to ; as well as, If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Within the set flow fluctuation tolerance range Inside, keep the magnet position or polishing wheel position unchanged; If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , then adjust the current magnet position or polishing wheel position according to the following formula: ； in, Indicates the current magnet position or polishing wheel position; If the actual magnetorheological fluid flow rate at the nozzle outlet corresponding to the current polishing point Not within the set flow fluctuation tolerance range The adjustment amount of the current magnet position or polishing wheel position , adjust the magnet position or polishing wheel position according to the following formula: ； in, Indicates the initial position of the magnet or polishing wheel.

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