Magnetorheological polishing equipment and polishing method based on laser tracker perception

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 laser tracker sensing. The laser tracker is used to measure real-time changes in the position of the magnetorheological polishing device during processing, and real-time constant control of the removal function is achieved by adjusting the speed of a liquid pump or a polishing wheel. This method does not require calibration of measuring equipment such as force sensors; it is unaffected by the weight of the magnetorheological polishing device, its own operating accuracy, operating speed, posture, or other factors. It can measure real-time changes in the position of the magnetorheological polishing device during processing, intuitively reflecting the position error of the magnetorheological polishing device, and has the advantages of low equipment cost and high measurement accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetorheological polishing, and in particular to a magnetorheological polishing device and a polishing method based on laser tracker perception. Background Art

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

[0003] To address the low motion precision of industrial robots, real-time control solutions for constant-force grinding and polishing have become a research hotspot. Force-position control has become a common method for controlling constant-force grinding and polishing in robots. A common application involves placing a force sensor between the machining tool and the industrial robot. The force sensor is first calibrated with gravity to ensure accurate measurement. The position error is calculated by measuring force changes. Constant-force control is then achieved by compensating for this position error using the robot itself or other motion compensation mechanisms. High-efficiency machining of large-aperture optical components requires magnetorheological (MR) machining equipment with large polishing wheels. These MR machining modules typically weigh hundreds of kilograms. However, for these MR machining modules, the force variation caused by the industrial robot's position error is only tens of Newtons. High-precision machining requires maintaining a constant force of a few Newtons or even a fraction of a Newton. This requires absolute measurement accuracy of one part per ten thousand for force sensors and other measuring equipment. Furthermore, the force sensor must be able to withstand variable speed and position movements. Force sensors that meet these requirements are often extremely expensive, significantly increasing the cost of the equipment. Summary of the Invention

[0004] The purpose of the present invention is to provide a magnetorheological polishing device and polishing method based on laser tracker sensing, so as to solve the problem that the use of high-precision force sensors will greatly increase the cost of the equipment.

[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 laser tracker 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 the test polishing element or the location of the element to be polished. The magnetorheological polishing module is used to polish the element 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 nozzle, polishing wheel and magnet are respectively installed on the magnetorheological mounting frame. The liquid pump is provided on 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 element to be polished.

[0009] A laser tracker, whose target ball is mounted on the tool end of the industrial robot, is used to measure the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball in different postures of the industrial robot, and convert the theoretical Z-axis spatial coordinates of the set polishing wheel working point into the theoretical Z-axis spatial coordinates of the target ball;

[0010] The computer is used to calculate the distance error between the actual Z-axis space coordinate and the theoretical Z-axis space coordinate of the target ball at each polishing trajectory point. The computer is also used to adjust the liquid pump speed according to the conversion relationship between the liquid pump speed and the polishing gap or adjust the polishing wheel speed according to the conversion relationship between the polishing wheel speed and the polishing gap when the distance error exceeds the set error range, thereby adjusting the removal function to maintain the removal function of each polishing trajectory point constant.

[0011] Furthermore, the magnetorheological polishing module further includes a polishing wheel drive device, which includes a driving motor, a driving wheel, a driven wheel and a synchronous belt. The driving motor is installed on a magnetorheological mounting frame, a bearing seat is installed on the magnetorheological mounting frame, 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.

[0012] A magnetorheological polishing method based on liquid pump speed regulation is implemented using the magnetorheological polishing device based on laser tracker sensing, comprising the following steps:

[0013] S1: Establishing a measurement coordinate system of a laser tracker, using the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculating the posture transformation relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball, and converting the set theoretical Z-axis spatial coordinate of the polishing wheel working point into the theoretical Z-axis spatial coordinate of the target ball according to the posture transformation relationship;

[0014] S2: Under different polishing gaps, by changing the liquid pump speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding liquid pump speed are fitted to obtain the conversion relationship between polishing gap and liquid pump speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump speed, Indicates the conversion relationship between the polishing gap and the liquid pump speed;

[0015] S3: polishing the component to be polished using a magnetorheological polishing device, measuring the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time using a laser tracker, and calculating the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates;

[0016] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the liquid pump speed of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump speed through the computer to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0017] Furthermore, the distance error , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point;

[0018] The maximum adjustment amount of the liquid pump speed is set in the computer , set the error range to , represents the maximum value of the distance error, then:

[0019] when When , the liquid pump speed at the current polishing track point is kept unchanged;

[0020] when And the liquid pump speed at the current polishing track point When the liquid pump speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0021] ;

[0022] when And the liquid pump speed at the current polishing track point When the liquid pump speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0023] ;

[0024] in, Indicates the set initial speed of the liquid pump.

[0025] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0026] A laser tracker is used to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis is not less than 10. With the help of the line fitting function of the laser tracker, a straight line is fitted to each measured point on the axis, and the fitted straight line is used as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

[0027] Furthermore, the process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows:

[0028] The tool end of the industrial robot is set to at least 12 postures, and the polishing wheel is driven to at least 12 different postures by the industrial robot;

[0029] The laser tracker is used to measure the spatial coordinates of the polishing wheel working point and the target ball in each posture of the industrial robot.

[0030] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0031] Place the target ball on at least 10 different positions on the outer surface of the polishing wheel and measure its coordinates. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is:

[0032] ;

[0033] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0034] By solving the following equations, the spatial coordinates corresponding to the minimum value of the Z-axis coordinate are used as the spatial coordinates of the polishing wheel working point :

[0035] ;

[0036] Where R represents the radius of the polishing wheel.

[0037] A magnetorheological polishing method based on polishing wheel speed regulation is implemented using the magnetorheological polishing device based on laser tracker sensing, comprising the following steps:

[0038] S1: Establishing a measurement coordinate system of a laser tracker, using the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculating the posture transformation relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball, and converting the set theoretical Z-axis spatial coordinate of the polishing wheel working point into the theoretical Z-axis spatial coordinate of the target ball according to the posture transformation relationship;

[0039] S2: Under different polishing gaps, by changing the polishing wheel speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding polishing wheel speed are fitted to obtain the conversion relationship between polishing gap and polishing wheel speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel speed, Indicates the conversion relationship between polishing gap and polishing wheel speed;

[0040] S3: polishing the component to be polished using a magnetorheological polishing device, measuring the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time using a laser tracker, and calculating the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates;

[0041] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel speed of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel speed by controlling the driving motor through the computer, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0042] Furthermore, the distance error , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point;

[0043] The maximum adjustment amount of the polishing wheel speed set in the computer is , set the error range to , represents the maximum value of the distance error, then:

[0044] when When , the polishing wheel speed at the current polishing track point remains unchanged;

[0045] when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0046] ;

[0047] when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0048] ;

[0049] in, Indicates the set initial speed of the polishing wheel.

[0050] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0051] A laser tracker is used to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis is not less than 10. With the help of the line fitting function of the laser tracker, a straight line is fitted to each measured point on the axis, and the fitted straight line is used as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

[0052] Furthermore, the process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows:

[0053] The tool end of the industrial robot is set to at least 12 postures, and the polishing wheel is driven to at least 12 different postures by the industrial robot;

[0054] The laser tracker is used to measure the spatial coordinates of the polishing wheel working point and the target ball in each posture of the industrial robot.

[0055] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0056] Place the target ball on at least 10 different positions on the outer surface of the polishing wheel and measure its coordinates. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is:

[0057] ;

[0058] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0059] By solving the following equations, the spatial coordinates corresponding to the minimum value of the Z-axis coordinate are used as the spatial coordinates of the polishing wheel working point :

[0060] ;

[0061] Where R represents the radius of the polishing wheel.

[0062] Compared to existing technologies, the present invention uses a laser tracker to measure the real-time changes in the position of the magnetorheological polishing device during the polishing process. This method achieves real-time, constant control of the removal function by adjusting the polishing wheel speed or the liquid pump speed. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the weight, operating accuracy, speed, and position of the magnetorheological polishing device, as well as other factors. It can measure the position changes of the polishing device in real time during the optical polishing process, providing a direct reflection of the polishing device's position error. This method offers the advantages of low equipment cost and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is a structural diagram of the magnetorheological polishing equipment based on laser tracker perception described in an embodiment of the present invention.

[0064] Figure numerals: polishing platform 1, element to be polished 101, test polishing element 102, industrial robot 201, magnetorheological mounting frame 202, polishing wheel 203, nozzle 205, liquid pump 206, drive motor 207, active wheel 208, driven wheel 209, synchronous belt 210, laser tracker 3, target ball 301, computer 4. DETAILED DESCRIPTION

[0065] 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.

[0066] 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.

[0067] To address the shortcomings of force-position control methods based on force sensors, the present invention proposes a magnetorheological polishing device and polishing method based on laser tracker sensing. This method uses a laser tracker to measure the real-time changes in the polishing device's position during the polishing process. Different control methods (polishing wheel speed adjustment / liquid pump speed adjustment) are then employed to achieve real-time stability of the removal function. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the weight of the magnetorheological machining module, the device's operating accuracy, operating speed, position, and other factors. It can measure changes in the polishing device's position in real time during the optical polishing process, intuitively reflecting the device's position error and offering the advantage of high measurement accuracy.

[0068] The following describes in detail how to maintain the constancy of the removal function with reference to a specific embodiment.

[0069] In the first aspect, this embodiment provides a magnetorheological polishing device based on laser tracker sensing, the structure of the device is as follows: Figure 1 Shown, including:

[0070] A polishing platform 1, on which a to-be-polished element 101 and a test polishing element 102 are arranged;

[0071] 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 (not shown), a nozzle 205, a liquid pump 206 and a polishing wheel drive device. The magnetorheological mounting frame 202 is installed on the tool of the industrial robot 201. At the end, a polishing wheel drive device is mounted on the magnetorheological mounting frame 202 and is used to drive the polishing wheel 203 to rotate and polish the element to be polished 101 or the test polishing element 102; a nozzle 205 is mounted on the magnetorheological mounting frame 202 and is used to spray magnetorheological fluid onto the polishing wheel 203; a magnet is mounted on the magnetorheological mounting frame 202 and is used to change the stiffness of the magnetorheological fluid; a liquid pump 206 is mounted on the industrial robot 201 and 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.

[0072] A laser tracker 3 is provided on one side of the polishing platform 1 and is used in conjunction with a target sphere 301. The target sphere 301 is located at the tool end of the industrial robot 201. The laser tracker 3 is used to measure the spatial coordinates of the polishing wheel working point (the polishing wheel working point refers to the lowest point of the polishing wheel when the magnetorheological polishing device is at zero point) of the industrial robot 201 in different postures and the spatial coordinates of the target sphere 301, and convert the theoretical Z-axis spatial coordinates of the set polishing wheel working point into the theoretical Z-axis spatial coordinates of the target sphere 301.

[0073] Computer 4 is used to calculate the distance error between the actual Z-axis spatial coordinate and the theoretical Z-axis spatial coordinate of the target ball 301 at each polishing trajectory point. Computer 4 is also used to adjust the liquid pump speed according to the conversion relationship between the liquid pump speed and the polishing gap or adjust the polishing wheel speed according to the conversion relationship between the polishing wheel speed and the polishing gap when the distance error exceeds the set error range, thereby adjusting the removal function to maintain the removal function of each polishing trajectory point constant.

[0074] The polishing wheel drive device includes a driving motor 207, a driving wheel 208, a driven wheel 209 and a synchronous belt 210. The driving motor 207 is installed on the magnetorheological mounting frame 202. A bearing seat is installed on the magnetorheological mounting frame 202. A bearing is installed in the bearing seat. The bearing is connected to the polishing wheel 203. The driven wheel 209 is mounted on the bearing. The driving wheel 208 is mounted on the output end of the driving motor 207. The synchronous belt 210 is tensioned on the driven wheel 209 and the driving wheel 208. The polishing wheel 203 is driven to rotate by the driving motor 207. Please refer to the Chinese patent with a publication date of July 12, 2024 and publication number CN118322074A.

[0075] 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.

[0076] The working principle of the magnetorheological polishing equipment based on laser tracker perception is as follows: first, the laser tracker 3 is used to calibrate the posture conversion relationship between the target ball 301 and the lowest point of the polishing wheel 203; then the operation control parameters of the magnetorheological polishing equipment are set; then the laser tracker 3 and the target ball 301 are used to measure the posture error of the magnetorheological polishing equipment in the moving state, and the measured motion posture is compared with the theoretical posture data to obtain the posture error information. The measured motion posture is calculated to obtain the polishing gap change data, and then the removal function change data is obtained. Finally, the removal function change is regulated by adjusting the rotation speed of the polishing wheel 203 or the rotation speed of the liquid pump 206 to achieve the desired control parameters, and finally the purpose of keeping the removal function of each polishing point constant is achieved.

[0077] In a second aspect, this embodiment further provides a magnetorheological polishing method based on liquid pump speed regulation, which is implemented using the magnetorheological polishing device based on laser tracker sensing, and includes the following steps:

[0078] S1: Establish a measurement coordinate system for the laser tracker, use the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculate the posture conversion relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball. According to the posture conversion relationship, the theoretical Z-axis spatial coordinate of the set polishing wheel working point is converted into the theoretical Z-axis spatial coordinate of the target ball.

[0079] The process of establishing the laser tracker measurement coordinate system is:

[0080] Use a laser tracker to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis must not be less than 10. Use the line fitting function of the laser tracker (this function is the basic function of the laser tracker) to fit a straight line to each measured point on the axis, and use the fitted straight line as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

[0081] The process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows:

[0082] The tool end of the industrial robot is set to at least 12 different postures, that is, the polishing wheel is driven by the industrial robot to at least 12 different postures. The spatial coordinates of the polishing wheel working point and the target ball in each posture are measured using a laser tracker.

[0083] The process of measuring the spatial coordinates of the target ball is as follows: the tool end of the industrial robot measures the position coordinates of the target ball in different postures. The spatial coordinates of the target ball corresponding to each posture measurement are .

[0084] The spatial coordinate measurement process of the polishing wheel working point is as follows: the target ball is placed on at least 10 different positions on the outer surface of the polishing wheel and its coordinates are measured. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is:

[0085] ;

[0086] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0087] Since the straight line passes through the working point of the polishing wheel, the spatial coordinates of the working point of the polishing wheel can be obtained by solving the following equations: , the spatial coordinates of the polishing wheel working point That is, the spatial coordinate corresponding to the minimum Z-axis coordinate in the solution of the equation system:

[0088] ;

[0089] Where R is the radius of the polishing wheel.

[0090] The tool end of the industrial robot repeats the above measurement process in different postures to obtain the spatial coordinates of the polishing wheel working point corresponding to each posture .

[0091] Calculate the spatial coordinates of the polishing wheel working point according to the following formula The spatial coordinates of the target ball The posture transformation relationship T between them is:

[0092] .

[0093] After obtaining the posture conversion relationship T, the theoretical Z-axis space coordinates of the set polishing wheel working point can be converted into the theoretical Z-axis space coordinates of the target ball according to the posture conversion relationship T.

[0094] S2: Under different polishing gaps, by changing the liquid pump speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding liquid pump speed are fitted to obtain the conversion relationship between polishing gap and liquid pump speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump speed, Indicates the conversion relationship between the polishing gap and the liquid pump speed.

[0095] The present invention realizes the change adjustment of the removal function by adjusting the liquid pump speed. The operation for determining the relationship between the liquid pump speed and the change of the removal function is as follows:

[0096] An industrial robot was used to drive the tool end to perform fixed-point processing at different positions on the surface of the test polishing element at different polishing gaps for a period of time. The liquid pump speed at each processing point was different. The volume removal rate of the removal function at each processing point under different polishing gaps was calculated. Based on the discrete volume removal rate of the removal function under different polishing gaps and its corresponding liquid pump speed, the Polyfit command of Matlab (this command is a basic general command of Matlab software) was used to fit the data to obtain the conversion relationship between the polishing gap and the liquid pump speed. This conversion relationship can be expressed as: .

[0097] 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 component to be polished changes.

[0098] Because the experimentally obtained discrete data corresponding to different polishing gaps is limited, the polishing gap actually measured during machining may not equal the experimentally obtained polishing gap data value. The solution is to use the nearest data, or round off. For example, the experimentally obtained relationship between the volumetric removal rate (MRR) and the liquid pump speed (SV) for polishing gaps of 1mm and 2mm corresponds to a 1.6mm polishing gap. In this case, the 2mm removal rate (MRR) is used to calculate the relationship between the polishing gap and the liquid pump speed (SV).

[0099] S3: Use magnetorheological polishing equipment to polish the component to be polished, use a laser tracker to measure the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time, and calculate the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates.

[0100] The spatial coordinates of the target ball are continuously measured while polishing the component to be polished, and the distance error between the actual Z-axis spatial coordinates and the theoretical Z-axis spatial coordinates of the target ball at each polishing trajectory point is calculated. , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the error range of the set distance error. Indicates the maximum value of the distance error.

[0101] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the liquid pump speed of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump speed through the computer to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0102] By adjusting the speed of the liquid pump, the removal function can be adjusted. During the polishing process of the polished component, the laser tracker continuously measures the spatial coordinates of the target ball. If the distance error Within the allowable error range, that is, , then the trajectory error of the magnetorheological polishing equipment meets the requirements of high-precision processing, and the current liquid pump speed remains unchanged; if The trajectory error of the magnetorheological polishing equipment does not meet the requirements of high-precision processing. At this time, it is necessary to calculate the polishing gap of the current polishing trajectory point. , Indicates the set initial polishing gap, based on the conversion relationship between the polishing gap at the current polishing track point and the liquid pump speed The liquid pump speed is calculated based on the set theoretical removal function volume removal rate and sent to the liquid pump motor through the computer. Finally, the change of the removal function is controlled by adjusting the liquid pump speed to achieve trajectory error control of the magnetorheological polishing equipment.

[0103] Since the change of the operating posture error of the magnetorheological polishing equipment is small, The change of is regarded as the change of polishing gap.

[0104] The maximum adjustment amount of the liquid pump speed is set in the computer ,but:

[0105] when When , the liquid pump speed at the current polishing track point is kept unchanged;

[0106] when And the liquid pump speed at the current polishing track point When the liquid pump speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0107] ;

[0108] when And the liquid pump speed at the current polishing track point When the liquid pump speed SV at the current polishing trajectory point is calculated according to the following formula i To make adjustments:

[0109] ;

[0110] in, Indicates the set initial speed of the liquid pump.

[0111] Calculate the maximum value of the adjustment amount when the liquid pump speed is The time required to control the magnetorheological processing module :

[0112] ;

[0113] in, Indicates the fastest adjustment rate of the liquid pump speed;

[0114] Count b data measured by the laser tracker in a second to get the time it takes for the laser tracker to measure a polishing track point ;

[0115] ;

[0116] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0117] ;

[0118] in, Indicates the distance between two adjacent polishing track points.

[0119] When generating a machining control program, if , then the generated processing control program is appropriate; if , it is necessary to increase the material removal thickness, extend the processing time, and regenerate the processing control program so that the processing residence time of each polishing trajectory point is .

[0120] During the entire processing process, a laser tracker and a target ball are used to continuously measure the posture error of the magnetorheological polishing equipment, and the operation trajectory is controlled in real time by the magnetorheological polishing equipment to achieve the desired control parameters, ensure the stability of the removal function during the processing, and ultimately achieve high-precision processing goals.

[0121] Compared to current mainstream real-time control solutions based on force sensors, this method uses a laser tracker to measure the real-time changes in the position of the magnetorheological polishing device during the polishing process and utilizes liquid pump speed regulation to achieve real-time constant control of the removal function. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the weight, operating accuracy, speed, and position of the magnetorheological polishing device, as well as other factors. It can measure the position changes of the polishing device in real time during the optical polishing process, providing a direct reflection of the polishing device's position error. This method offers the advantages of low equipment cost and high measurement accuracy.

[0122] In a third aspect, this embodiment further provides a magnetorheological polishing method based on polishing wheel speed regulation, which is implemented using the magnetorheological polishing device based on laser tracker sensing, and includes the following steps:

[0123] S1: Establish a measurement coordinate system for the laser tracker, use the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculate the posture conversion relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball. According to the posture conversion relationship, the theoretical Z-axis spatial coordinate of the set polishing wheel working point is converted into the theoretical Z-axis spatial coordinate of the target ball.

[0124] The process of establishing the laser tracker measurement coordinate system is:

[0125] Use a laser tracker to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis must not be less than 10. Use the line fitting function of the laser tracker (this function is the basic function of the laser tracker) to fit a straight line to each measured point on the axis, and use the fitted straight line as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

[0126] The process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows:

[0127] The tool end of the industrial robot is set to at least 12 different postures, that is, the polishing wheel is driven by the industrial robot to at least 12 different postures. The spatial coordinates of the polishing wheel working point and the target ball in each posture are measured using a laser tracker.

[0128] The process of measuring the spatial coordinates of the target ball is as follows: the tool end of the industrial robot measures the position coordinates of the target ball in different postures. The spatial coordinates of the target ball corresponding to each posture measurement are .

[0129] The spatial coordinate measurement process of the polishing wheel working point is as follows: the target ball is placed on at least 10 different positions on the outer surface of the polishing wheel and its coordinates are measured. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is:

[0130] ;

[0131] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0132] Since the straight line passes through the working point of the polishing wheel, the spatial coordinates of the working point of the polishing wheel can be obtained by solving the following equations: , the spatial coordinates of the polishing wheel working point That is, the spatial coordinate corresponding to the minimum Z-axis coordinate in the solution of the equation system:

[0133] ;

[0134] Where R is the radius of the polishing wheel.

[0135] The tool end of the industrial robot repeats the above measurement process in different postures to obtain the spatial coordinates of the polishing wheel working point corresponding to each posture .

[0136] Calculate the spatial coordinates of the polishing wheel working point according to the following formula The spatial coordinates of the target ball The posture transformation relationship T between them is:

[0137] .

[0138] After obtaining the posture conversion relationship T, the theoretical Z-axis space coordinates of the set polishing wheel working point can be converted into the theoretical Z-axis space coordinates of the target ball according to the posture conversion relationship T.

[0139] S2: Under different polishing gaps, by changing the polishing wheel speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding polishing wheel speed are fitted to obtain the conversion relationship between polishing gap and polishing wheel speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel speed, Indicates the conversion relationship between polishing gap and polishing wheel speed.

[0140] The present invention realizes the change adjustment of the removal function by adjusting the polishing wheel speed. The operation for determining the relationship between the polishing wheel speed and the change of the removal function is as follows:

[0141] An industrial robot was used to drive the tool end to perform fixed-point processing at different positions on the surface of the test polishing element at different polishing gaps for a period of time. The polishing wheel speed at each processing point was different. The removal function volume removal rate of each processing point at different polishing gaps was calculated. Based on the discrete removal function volume removal rate at different polishing gaps and its corresponding polishing wheel speed, the Polyfit command of Matlab (this command is a basic general command of Matlab software) was used to fit the data to obtain the conversion relationship between polishing gap and polishing wheel speed. This conversion relationship can be expressed as: .

[0142] 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 component to be polished changes.

[0143] Because the amount of discrete data corresponding to different polishing gaps obtained experimentally is limited, the polishing gap actually measured during machining may not equal the polishing gap data value obtained experimentally. The solution is to use the nearest data, that is, the principle of rounding. For example, the experimental conversion relationship between the removal function volume removal rate (MRR) and the polishing wheel speed (V) corresponding to polishing gaps of 1mm and 2mm was obtained. However, the polishing gap during machining is 1.6mm. In this case, the removal function volume removal rate (MRR) of 2mm is selected to calculate the conversion relationship between the polishing gap and the polishing wheel speed (V).

[0144] S3: Use magnetorheological polishing equipment to polish the component to be polished, use a laser tracker to measure the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time, and calculate the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates.

[0145] The spatial coordinates of the target ball are continuously measured while polishing the component to be polished, and the distance error between the actual Z-axis spatial coordinates and the theoretical Z-axis spatial coordinates of the target ball at each polishing trajectory point is calculated. , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the error range of the set distance error, Indicates the maximum value of the distance error.

[0146] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel speed of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel speed by controlling the driving motor through the computer, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0147] By adjusting the polishing wheel speed, the removal function can be adjusted. During the polishing process of the polished component, the laser tracker continuously measures the spatial coordinates of the target ball. If the distance error Within the allowable error range, that is, , then the trajectory error of the magnetorheological polishing equipment meets the requirements of high-precision processing and maintains the current polishing wheel speed unchanged; if The trajectory error of the magnetorheological polishing equipment does not meet the requirements of high-precision processing. At this time, it is necessary to calculate the polishing gap of the current polishing trajectory point. , Indicates the set initial polishing gap, based on the polishing gap of the current polishing track point The conversion relationship between the polishing wheel speed The polishing wheel speed is calculated based on the set theoretical removal function volume removal rate and sent to the drive motor through the computer. Finally, the change of the removal function is regulated by adjusting the polishing wheel speed to achieve trajectory error control of the magnetorheological polishing equipment.

[0148] Since the change of the operating posture error of the magnetorheological polishing equipment is small, The change of is regarded as the change of polishing gap.

[0149] In order to ensure the processing safety and the polishing wheel speed will not affect the processing, the maximum adjustment amount of the polishing wheel speed is set in the computer to ,but:

[0150] when When , the polishing wheel speed at the current polishing track point remains unchanged;

[0151] when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0152] ;

[0153] when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments:

[0154] ;

[0155] in, Indicates the set initial speed of the polishing wheel.

[0156] Calculate the maximum adjustment amount when the polishing wheel speed is The time required to control the magnetorheological processing module :

[0157] ;

[0158] in, Indicates the fastest adjustment rate of the polishing wheel speed;

[0159] Count b data measured by the laser tracker in a second to get the time it takes for the laser tracker to measure a polishing track point ;

[0160] ;

[0161] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0162] ;

[0163] in, Indicates the distance between two adjacent polishing track points.

[0164] When generating a machining control program, if , then the generated processing control program is appropriate; if , it is necessary to increase the material removal thickness, extend the processing time, and regenerate the processing control program so that the processing residence time of each polishing trajectory point is .

[0165] During the entire processing process, a laser tracker and a target ball are used to continuously measure the posture error of the magnetorheological polishing equipment, and the operation trajectory is controlled in real time by the magnetorheological polishing equipment to achieve the desired control parameters, ensure the stability of the removal function during the processing, and ultimately achieve high-precision processing goals.

[0166] Compared to current mainstream real-time control solutions based on force sensors, this method uses a laser tracker to measure the real-time changes in the magnetorheological polishing device's posture during the polishing process, and uses polishing wheel adjustment to achieve real-time, constant control of the removal function. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the weight, operating accuracy, speed, posture, and other factors of the magnetorheological polishing device. It can measure the polishing device's posture changes in real time during the optical polishing process, intuitively reflecting the polishing device's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0167] 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.

[0168] 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 laser tracker 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 nozzle, the polishing wheel, 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. A laser tracker, whose target ball is mounted on the tool end of the industrial robot, is used to measure the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball in different postures of the industrial robot, and convert the theoretical Z-axis spatial coordinates of the set polishing wheel working point into the theoretical Z-axis spatial coordinates of the target ball; The computer is used to calculate the distance error between the actual Z-axis space coordinate and the theoretical Z-axis space coordinate of the target ball at each polishing trajectory point. The computer is also used to adjust the liquid pump speed according to the conversion relationship between the liquid pump speed and the polishing gap or adjust the polishing wheel speed according to the conversion relationship between the polishing wheel speed and the polishing gap when the distance error exceeds the set error range, thereby adjusting the removal function to maintain the removal function of each polishing trajectory point constant.

2. The magnetorheological polishing equipment based on laser tracker perception according to claim 1 is characterized in that: The magnetorheological polishing module further includes a polishing wheel drive device, which includes a drive motor, a driving wheel, a driven wheel and a synchronous belt. The drive motor is installed on a magnetorheological mounting frame, a bearing seat is installed on the magnetorheological mounting frame, 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 drive motor, and the synchronous belt is tensioned on the driven wheel and the driving wheel.

3. A magnetorheological polishing method based on liquid pump speed regulation, implemented using the magnetorheological polishing device based on laser tracker perception according to claim 1 or 2, characterized in that: The steps include: S1: Establishing a measurement coordinate system of a laser tracker, using the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculating the posture transformation relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball, and converting the set theoretical Z-axis spatial coordinate of the polishing wheel working point into the theoretical Z-axis spatial coordinate of the target ball according to the posture transformation relationship; S2: Under different polishing gaps, by changing the liquid pump speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding liquid pump speed are fitted to obtain the conversion relationship between polishing gap and liquid pump speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump speed, Indicates the conversion relationship between the polishing gap and the liquid pump speed; S3: polishing the component to be polished using a magnetorheological polishing device, measuring the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time using a laser tracker, and calculating the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates; S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the liquid pump speed of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump speed through the computer to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

4. The magnetorheological polishing method based on liquid pump speed regulation according to claim 3 is characterized in that: Distance error , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point; The maximum adjustment amount of the liquid pump speed is set in the computer , set the error range to , represents the maximum value of the distance error, then: when When , the liquid pump speed at the current polishing track point is kept unchanged; when And the liquid pump speed at the current polishing track point When the liquid pump speed at the current polishing track point is calculated according to the following formula To make adjustments: ； when And the liquid pump speed at the current polishing track point When the liquid pump speed at the current polishing track point is calculated according to the following formula To make adjustments: ； in, Indicates the set initial speed of the liquid pump.

5. The magnetorheological polishing method based on liquid pump speed regulation according to claim 3 is characterized in that: The process of establishing the measurement coordinate system of the laser tracker is: A laser tracker is used to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis is not less than 10. With the help of the line fitting function of the laser tracker, a straight line is fitted to each measured point on the axis, and the fitted straight line is used as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

6. The magnetorheological polishing method based on liquid pump speed regulation according to claim 3 is characterized in that: The process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows: The tool end of the industrial robot is set to at least 12 postures, and the polishing wheel is driven to at least 12 different postures by the industrial robot; The laser tracker is used to measure the spatial coordinates of the polishing wheel working point and the target ball in each posture of the industrial robot. The measurement process of the spatial coordinates of the polishing wheel working point is: Place the target ball on at least 10 different positions on the outer surface of the polishing wheel and measure its coordinates. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is: ； Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot; By solving the following equations, the spatial coordinates corresponding to the minimum value of the Z-axis coordinate are used as the spatial coordinates of the polishing wheel working point : ； Where R represents the radius of the polishing wheel.

7. A magnetorheological polishing method based on polishing wheel speed regulation, implemented using the magnetorheological polishing device based on laser tracker perception according to claim 2, characterized in that: The steps include: S1: Establishing a measurement coordinate system of a laser tracker, using the laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot, and calculating the posture transformation relationship between the spatial coordinates of the polishing wheel working point and the spatial coordinates of the target ball, and converting the set theoretical Z-axis spatial coordinate of the polishing wheel working point into the theoretical Z-axis spatial coordinate of the target ball according to the posture transformation relationship; S2: Under different polishing gaps, by changing the polishing wheel speed, each processing point of the test polishing element is fixed-point processed, and the removal function volume removal rate of each processing point under different polishing gaps is calculated. The discrete removal function volume removal rate under different polishing gaps and its corresponding polishing wheel speed are fitted to obtain the conversion relationship between polishing gap and polishing wheel speed. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel speed, Indicates the conversion relationship between polishing gap and polishing wheel speed; S3: polishing the component to be polished using a magnetorheological polishing device, measuring the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point in real time using a laser tracker, and calculating the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point and the theoretical Z-axis spatial coordinates; S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel speed of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel speed by controlling the drive motor through the computer, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

8. The magnetorheological polishing method based on polishing wheel speed regulation according to claim 7, characterized in that: Distance error , Indicates the actual Z-axis spatial coordinate of the target ball at each polishing trajectory point, Indicates the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point; The maximum adjustment amount of the polishing wheel speed set in the computer is , set the error range to , represents the maximum value of the distance error, then: when When , the polishing wheel speed at the current polishing track point remains unchanged; when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments: ； when And the polishing wheel speed at the current polishing track point When the polishing wheel speed at the current polishing track point is calculated according to the following formula To make adjustments: ； in, Indicates the set initial speed of the polishing wheel.

9. The magnetorheological polishing method based on polishing wheel speed regulation according to claim 7, characterized in that: The process of establishing the measurement coordinate system of the laser tracker is: A laser tracker is used to measure the coordinates of points on each axis when the industrial robot moves along the X-axis and Y-axis of the tool coordinate system. The number of measured points on each axis is not less than 10. With the help of the line fitting function of the laser tracker, a straight line is fitted to each measured point on the axis, and the fitted straight line is used as the measurement coordinate system of the laser tracker, that is, the measurement coordinate system of the laser tracker is parallel to the tool coordinate system of the industrial robot.

10. The magnetorheological polishing method based on polishing wheel speed regulation according to claim 7, characterized in that: The process of using a laser tracker to measure the spatial coordinates of the polishing wheel working point and the target ball in different postures of the industrial robot is as follows: The tool end of the industrial robot is set to at least 12 postures, and the polishing wheel is driven to at least 12 different postures by the industrial robot; The laser tracker is used to measure the spatial coordinates of the polishing wheel working point and the target ball in each posture of the industrial robot. The measurement process of the spatial coordinates of the polishing wheel working point is: Place the target ball on at least 10 different positions on the outer surface of the polishing wheel and measure its coordinates. The center point coordinates of the polishing wheel are obtained by the ball fitting function of the laser tracker. , the straight line passing through the center point of the polishing wheel is: ； Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot; By solving the following equations, the spatial coordinates corresponding to the minimum value of the Z-axis coordinate are used as the spatial coordinates of the polishing wheel working point : ； Where R represents the radius of the polishing wheel.

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