Magnetorheological polishing system 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 system 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 system during processing, and real-time constant control of the removal function is achieved by adjusting the intensity of the electromagnetic magnetic field or simultaneously adjusting the position of the polishing wheel and the intensity of the electromagnetic magnetic field. This method does not require calibration of measuring equipment such as force sensors; it is unaffected by the weight of the magnetorheological polishing system, its own operating accuracy, operating speed, posture, and other factors. It can measure real-time changes in the position of the magnetorheological polishing system during processing, intuitively reflecting the position error of the magnetorheological polishing system, 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 system and 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 system 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 equipment.

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

[0006] A magnetorheological polishing system 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 a test polishing element or the location of an element to be polished. The magnetorheological polishing module is used to process the element to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, an electromagnet, a liquid pump, a position adjustment device and a current intensity controller. The magnetorheological mounting frame is installed on the tool end of the industrial robot. The current intensity controller, the position adjustment device, the nozzle and the electromagnet 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 electromagnet is used to change the stiffness of the magnetorheological fluid. The position adjustment device is used to adjust the position of the polishing wheel. The polishing wheel is used to process the test polishing element or the element to be polished. The current intensity controller is used to control the current flowing through the electromagnet and adjust the magnetic field strength of the electromagnet.

[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 electromagnetic magnetic field strength according to the conversion relationship between the electromagnetic magnetic field strength and the polishing gap, or to adjust the polishing wheel position and the electromagnetic magnetic field strength at the same time according to the conversion relationship between the polishing wheel position and the polishing gap, so as to adjust the removal function and maintain the removal function of each polishing trajectory point constant when the distance error exceeds a set error range.

[0011] Furthermore, the position adjustment device 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 polishing wheel is connected to the connecting plate.

[0012] 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.

[0013] A magnetorheological polishing method based on adjusting the magnetic field strength of an electromagnet is implemented using the magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0014] 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;

[0015] S2: Under different polishing gaps, by changing the electromagnetic magnetic field strength, fixed-point processing is performed on each processing point of the test polishing element, 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 electromagnetic magnetic field strength are fitted to obtain the conversion relationship between polishing gap and electromagnetic magnetic field strength. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, represents the strength of the electromagnet's magnetic field, Indicates the conversion relationship between the polishing gap and the magnetic field strength of the electromagnet;

[0016] S3: The component to be polished is processed using a magnetorheological polishing system, and the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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;

[0017] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the electromagnetic magnetic field strength through the computer-controlled current intensity controller to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0018] 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;

[0019] The maximum adjustment value of the electromagnetic magnetic field strength is set in the computer. , set the error range to , represents the maximum value of the distance error, then:

[0020] when When , the intensity of the electromagnet magnetic field at the current polishing track point is kept unchanged;

[0021] when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments:

[0022] ;

[0023] when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments:

[0024] ;

[0025] in, Indicates the set initial magnetic field strength of the electromagnet.

[0026] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0027] 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.

[0028] 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:

[0029] 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;

[0030] 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.

[0031] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0032] 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:

[0033] ;

[0034] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0035] 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 :

[0036] ;

[0037] Where R represents the radius of the polishing wheel.

[0038] A magnetorheological polishing method based on simultaneous adjustment of polishing wheel position and magnetic field intensity is implemented using the above-mentioned magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0039] 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;

[0040] S2: Under different polishing gaps, by changing the polishing wheel position, 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 position are fitted to obtain the conversion relationship between polishing gap and polishing wheel position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel position, Indicates the conversion relationship between the polishing gap and the polishing wheel position;

[0041] S3: The component to be polished is processed using a magnetorheological polishing system, and the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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;

[0042] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel position and the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel position through the computer-controlled position adjustment device, and at the same time control the current intensity controller to adjust the electromagnetic magnetic field strength, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0043] 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;

[0044] The maximum adjustment of the polishing wheel position is set in the computer , the maximum adjustment value of the electromagnetic magnetic field strength is , set the error range to , represents the maximum value of the distance error, then:

[0045] when When the polishing wheel position at the current polishing track point is maintained and the electromagnetic magnetic field strength constant;

[0046] when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments:

[0047] ;

[0048] ;

[0049] Where r represents the distance between the electromagnet and the polishing wheel, M represents the magnetic moment, and k is the proportional coefficient;

[0050] when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments:

[0051] ;

[0052] ;

[0053] in, Indicates the set initial position of the polishing wheel. Indicates the set initial magnetic field strength of the electromagnet.

[0054] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0055] 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.

[0056] 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:

[0057] 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;

[0058] 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.

[0059] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0060] 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:

[0061] ;

[0062] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0063] 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 :

[0064] ;

[0065] Where R represents the radius of the polishing wheel.

[0066] Compared to existing technologies, the present invention uses a laser tracker to measure the real-time changes in the magnetorheological polishing system's posture during the polishing process. This method achieves real-time, constant control of the removal function by adjusting the intensity of the electromagnet's magnetic field or by simultaneously adjusting the polishing wheel's position and the intensity of the electromagnet's magnetic field. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the magnetorheological polishing system's weight, operating accuracy, speed, posture, and other factors. It can measure the polishing system's posture changes in real time during the optical polishing process, intuitively reflecting the polishing system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 A schematic structural diagram of a magnetorheological polishing system based on laser tracker sensing according to an embodiment of the present invention at one viewing angle;

[0068] Figure 2 A schematic structural diagram of the magnetorheological polishing system based on laser tracker sensing according to an embodiment of the present invention from another perspective;

[0069] Figure 3 A schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention at one viewing angle;

[0070] Figure 4 A schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention from another perspective;

[0071] Figure 5 This is a structural diagram of the position adjustment device described in an embodiment of the present invention.

[0072] Figure numerals: polishing platform 1, element to be polished 101, test polishing element 102, industrial robot 201, magnetorheological mounting frame 202, polishing wheel 203, electromagnet 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, current intensity controller 218, mounting plate 219, laser tracker 3, target ball 301, computer 4. DETAILED DESCRIPTION

[0073] 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.

[0074] 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.

[0075] To address the shortcomings of force-position control methods based on force sensors, the present invention proposes a magnetorheological polishing system and polishing method based on laser tracker sensing. This system uses a laser tracker to measure the real-time changes in the polishing system's position during the polishing process. Using different control methods (electromagnetic field intensity adjustment / simultaneous adjustment of polishing wheel position and electromagnet field intensity), the system achieves 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 equipment's operating accuracy, operating speed, position, and other factors. It can measure the polishing system's position changes in real time during the optical polishing process, intuitively reflecting the polishing system's position errors and offering high measurement accuracy.

[0076] The following describes in detail how to maintain the constancy of the removal function with reference to a specific embodiment.

[0077] In the first aspect, this embodiment provides a magnetorheological polishing system based on laser tracker sensing, the structure of the device is as follows: Figure 1-Figure 5 Shown, including:

[0078] A polishing platform 1, on which a to-be-polished element 101 and a test polishing element 102 are arranged;

[0079] 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 position of the test polishing element 102 or to drive the magnetorheological polishing module to move to the position of the element to be polished 101; the magnetorheological polishing module is used to process 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, an electromagnet 204, a nozzle 205, a liquid pump 206, a current intensity controller 218, a position adjustment device and a polishing wheel driving device. 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 for driving the polishing wheel 203 to rotate and process the element to be polished 101 or the test polishing element 102; the nozzle 205 is installed on the magnetorheological mounting frame 202 for spraying magnetorheological fluid onto the polishing wheel 203; the electromagnet 204 is installed on the mounting plate 21 9, close to the working point of the polishing wheel 203 (the working point of the polishing wheel 203 is the closest point between the polishing wheel 203 and the surface of the element to be polished 101 along the normal direction of the surface of the element to be polished 101), and the mounting plate 219 is mounted on the magnetorheological mounting frame 202 for changing the stiffness of the magnetorheological fluid; the current intensity controller 218 is mounted on the magnetorheological mounting frame 202 for controlling the current flowing through the electromagnet 204 and adjusting the magnetic field strength of the electromagnet 204. The current intensity controller 218 preferably adopts a Smart200 series DA conversion module from Siemens; the liquid pump 206 is mounted on the industrial robot 201 or arranged on one side of the industrial robot 201. 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 adopts the DFLD vertical multi-stage pump of Shanghai Oriental Pump Industry Co., Ltd.; the position adjustment device is mounted on the magnetorheological mounting frame 202 for adjusting the position of the polishing wheel 203;

[0080] 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 system 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.

[0081] 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 magnetic field strength of the electromagnet 204 according to the conversion relationship between the magnetic field strength of the electromagnet 204 and the polishing gap, or to adjust the position of the polishing wheel 203 and the magnetic field strength of the electromagnet 204 according to the conversion relationship between the position of the polishing wheel 203 and the polishing gap, so as to adjust the removal function and maintain the removal function of each polishing trajectory point constant.

[0082] The position adjustment device includes 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 polishing wheel 203 is connected to the connecting plate 209, and the ball screw stepper motor 208 drives the polishing wheel 203 to move for position adjustment.

[0083] The polishing wheel drive device includes a drive motor 210, a driving wheel 211, a driven wheel 212, and a synchronous belt 213. The drive motor 210 is mounted on a connecting plate 209. A bearing seat is mounted on the connecting plate 209. A bearing is mounted 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 drive motor 210. The synchronous belt 213 is tensioned on the driven wheel 212 and the driving wheel 211. The drive motor 210 drives the polishing wheel 203 to rotate. See Chinese Patent Publication No. CN118322074A, published on July 12, 2024. The drive motor 210 drives the polishing wheel 203 to rotate at high speed, bringing the magnetorheological fluid into the magnetic field. Under the influence of the magnetic field, the magnetorheological fluid flow forms a magnetorheological ribbon.

[0084] In the embodiment of the present invention, to ensure that the polishing wheel 203 and the electromagnet 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.

[0085] 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.

[0086] The working principle of the magnetorheological polishing system 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 system are set; then the laser tracker 3 and the target ball 301 are used to measure the posture error of the magnetorheological polishing system in the motion 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 magnetic field strength of the electromagnet 204 or by adjusting the position of the polishing wheel 203 and the magnetic field strength of the electromagnet 204 at the same time to achieve the desired control parameters, and ultimately achieve the purpose of keeping the removal function of each polishing point constant.

[0087] In a second aspect, this embodiment further provides a magnetorheological polishing method based on adjusting the magnetic field strength of an electromagnet, which is implemented using the magnetorheological polishing system based on laser tracker sensing, and includes the following steps:

[0088] 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.

[0089] The process of establishing the laser tracker measurement coordinate system is:

[0090] 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.

[0091] 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:

[0092] 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.

[0093] 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 .

[0094] The spatial coordinate measurement process of the polishing wheel working point is as follows: a target ball is placed at at least 10 different positions on the outer surface of the polishing wheel and its coordinates are measured. The ball fitting function of the laser tracker (this function is the basic function of the laser tracker) is used to obtain the coordinates of the center point of the polishing wheel (x2, y2, z2). The posture information of the current tool end of the industrial robot can be obtained through the teaching device of the industrial robot, that is, the straight line passing through the center point of the polishing wheel can be obtained:

[0095] ;

[0096] Among them, a, b and c are the normal vectors of the straight line, which can be obtained through the teaching pendant of the industrial robot.

[0097] 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:

[0098] ;

[0099] Where R is the radius of the polishing wheel.

[0100] 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 .

[0101] 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:

[0102] .

[0103] 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.

[0104] S2: Under different polishing gaps, by changing the electromagnetic magnetic field strength, fixed-point processing is performed on each processing point of the test polishing element, 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 electromagnetic magnetic field strength are fitted to obtain the conversion relationship between polishing gap and electromagnetic magnetic field strength. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, represents the strength of the electromagnet's magnetic field, It represents the conversion relationship between the polishing gap and the magnetic field strength of the electromagnet.

[0105] The present invention realizes the change adjustment of the removal function by adjusting the intensity of the electromagnetic magnetic field. The operation for determining the relationship between the intensity of the electromagnetic magnetic field and the change of the removal function is as follows:

[0106] 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 electromagnetic magnetic field strength 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 electromagnetic magnetic field strength, 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 electromagnetic magnetic field strength. This conversion relationship can be expressed as: .

[0107] 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.

[0108] 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 value, or round off. For example, the experimentally obtained conversion relationship between the volumetric removal rate (MRR) and the electromagnetic magnetic field strength (B) for polishing gaps of 1 mm and 2 mm was obtained. However, the polishing gap during machining is 1.6 mm. In this case, the volumetric removal rate (MRR) of the 2 mm polishing gap is used to calculate the conversion relationship between the polishing gap and the electromagnetic magnetic field strength (B).

[0109] S3: The magnetorheological polishing system is used to process the polishing component. The actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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.

[0110] 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.

[0111] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the electromagnetic magnetic field strength through the computer-controlled current intensity controller to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0112] During the polishing process, the laser tracker continuously measures the spatial coordinates of the target ball. 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 electromagnetic magnetic field strength unchanged; if , the trajectory error of the magnetorheological polishing system 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 electromagnetic magnetic field strength The set theoretical removal function volume removal rate calculates the electromagnetic magnetic field strength and sends it to the current intensity controller through the computer. Finally, the change of the removal function is regulated by adjusting the electromagnetic magnetic field strength to achieve trajectory error control of the magnetorheological polishing system.

[0113] Since the variation of the operating posture error of the magnetorheological polishing system is small, The change of is regarded as the change of polishing gap.

[0114] In order to ensure the processing safety and the electromagnetic magnetic field strength will not affect the processing, the maximum adjustment value of the electromagnetic magnetic field strength is set in the computer to , the error range is set to , represents the maximum value of the distance error, then:

[0115] when When , the intensity of the electromagnet magnetic field at the current polishing track point is kept unchanged;

[0116] when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments:

[0117] ;

[0118] when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments:

[0119] ;

[0120] in, Indicates the set initial magnetic field strength of the electromagnet.

[0121] Calculate the maximum value of the adjustment amount of the electromagnetic magnetic field strength When the magnetorheological processing module needs to be regulated :

[0122] ;

[0123] in, It is the maximum adjustment rate of magnetic field strength change.

[0124] 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 ;

[0125] ;

[0126] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0127] ;

[0128] in, Indicates the distance between two adjacent polishing track points.

[0129] 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 .

[0130] During the entire machining process, a laser tracker and a target ball are used to continuously measure the posture error of the magnetorheological polishing system, and the magnetorheological polishing system is used to control the running trajectory in real time to achieve the desired control parameters, ensure the stability of the removal function during the machining process, and ultimately achieve high-precision machining goals.

[0131] 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 system's posture during the polishing process and adjusts the electromagnetic field intensity to achieve real-time constant control of the removal function. This method requires no calibration of measurement equipment such as force sensors and is unaffected by the weight of the magnetorheological polishing system, its operating accuracy, operating speed, posture, and other factors. It can measure the polishing system's posture changes in real time during the optical polishing process, intuitively reflecting the polishing system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0132] In a third aspect, this embodiment further provides a magnetorheological polishing method based on simultaneous adjustment of the polishing wheel position and magnetic field strength, which is implemented using the above-mentioned magnetorheological polishing system based on laser tracker sensing, and includes the following steps:

[0133] 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.

[0134] The process of establishing the laser tracker measurement coordinate system is:

[0135] 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.

[0136] 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:

[0137] 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.

[0138] 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 .

[0139] 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:

[0140] ;

[0141] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0142] 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:

[0143] ;

[0144] Where R is the radius of the polishing wheel.

[0145] 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 .

[0146] 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:

[0147] .

[0148] 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.

[0149] S2: Under different polishing gaps, by changing the polishing wheel position, 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 position are fitted to obtain the conversion relationship between polishing gap and polishing wheel position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel position, Indicates the conversion relationship between the polishing gap and the polishing wheel position.

[0150] The present invention realizes the change adjustment of the removal function by simultaneously adjusting the polishing wheel position and the magnetic field strength of the electromagnet. The operation for determining the relationship between the polishing wheel position and the change of the removal function is as follows:

[0151] 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 position of each processing point was different. The removal function volume removal rate of each processing point under different polishing gaps was calculated. Based on the discrete removal function volume removal rate under different polishing gaps and its corresponding polishing wheel position, 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 polishing wheel position. This conversion relationship can be characterized as follows: .

[0152] 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 element to be polished changes. Changing the polishing wheel position individually means changing the polishing wheel position based on each polishing gap.

[0153] For example, if the polishing gap is set to 1mm and 2mm, when collecting data for the experiment, first adjust the polishing gap to 1mm, then change the polishing wheel position alone, and collect data. After this set of experiments is completed, adjust the polishing gap to 2mm, then change the polishing wheel position alone, and collect data.

[0154] 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 experimentally obtained polishing gap data value. The solution is to use the nearest data, or round off. For example, if the experimental results show the conversion relationship between the removal function volume removal rate (MRR) and the polishing wheel position (LW) for polishing gaps of 1mm and 2mm, but the polishing gap during machining is 1.6mm, the removal function volume removal rate (MRR) of 2mm is selected to calculate the conversion relationship between the polishing gap and the polishing wheel position (LW).

[0155] S3: The magnetorheological polishing system is used to process the polishing component. The actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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.

[0156] 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.

[0157] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel position and the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel position through the computer-controlled position adjustment device, and at the same time control the current intensity controller to adjust the electromagnetic magnetic field strength, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

[0158] By adjusting the polishing wheel position and the strength of the electromagnet magnetic field at the same time, 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 is wrong, Within the allowable error range, that is, The trajectory error of the magnetorheological polishing system meets the requirements of high-precision processing, maintaining the current polishing wheel position and the electromagnetic magnetic field strength unchanged; if , the trajectory error of the magnetorheological polishing system 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 and the polishing wheel position at the current polishing track point The polishing wheel position is calculated based on the set theoretical removal function volume removal rate, and sent to the ball screw stepper motor through the computer to adjust the polishing wheel position. When the polishing wheel position changes, the relative distance between the polishing wheel and the electromagnet is changed, resulting in a change in the magnetic field strength on the outer surface of the polishing wheel. At this time, the magnetic field strength of the electromagnet needs to be changed to ensure that the magnetic field strength on the outer surface of the polishing wheel remains unchanged. Finally, by simultaneously adjusting the polishing wheel position and the magnetic field strength of the electromagnet, the change of the removal function is regulated to achieve trajectory error control of the magnetorheological polishing system.

[0159] Since the variation of the operating posture error of the magnetorheological polishing system is small, The change of is regarded as the change of polishing gap.

[0160] In order to ensure the processing safety and the polishing wheel position and magnetic field strength will not affect the processing, the maximum adjustment amount of the polishing wheel position is set in the computer to , the maximum adjustment value of the electromagnetic magnetic field strength is , set the error range to , represents the maximum value of the distance error, then:

[0161] when When the polishing wheel position at the current polishing track point is maintained and the electromagnetic magnetic field strength constant;

[0162] when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments:

[0163] ;

[0164] ;

[0165] Where r represents the distance between the electromagnet and the polishing wheel, M represents the magnetic moment, and k is the proportional coefficient;

[0166] when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments:

[0167] ;

[0168] ;

[0169] in, Indicates the set initial position of the polishing wheel. Indicates the set initial magnetic field strength of the electromagnet.

[0170] Calculate the maximum value of the adjustment amount of the electromagnetic magnetic field strength When the magnetorheological processing module needs to be regulated :

[0171] ;

[0172] in, It is the maximum adjustment rate of magnetic field strength change.

[0173] Calculate the adjustment amount at the polishing wheel position as the maximum value When the magnetorheological processing module needs to be regulated :

[0174] ;

[0175] in, It is the maximum moving speed of the position adjustment device.

[0176] 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 :

[0177] ;

[0178] Calculate the maximum speed V of the industrial robot max The minimum moving time between two adjacent polishing track points :

[0179] ;

[0180] in, Indicates the distance between two adjacent processing positions.

[0181] When generating a machining control program, if If , it is necessary to increase the material removal thickness, extend the processing time, and regenerate the processing control program. . express and The maximum value in .

[0182] During the entire machining process, a laser tracker and a target ball are used to continuously measure the posture error of the magnetorheological polishing system, and the magnetorheological polishing system is used to control the running trajectory in real time to achieve the desired control parameters, ensure the stability of the removal function during the machining process, and ultimately achieve high-precision machining goals.

[0183] 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 system's posture during the polishing process. This method achieves real-time, constant control of the removal function by adjusting the electromagnetic magnetic field intensity or by simultaneously adjusting the polishing wheel position and the electromagnetic magnetic field intensity. This method eliminates the need for calibration of measurement equipment such as force sensors and is unaffected by the magnetorheological polishing system's weight, operating accuracy, speed, posture, and other factors. It can measure the polishing system's posture changes in real time during the optical polishing process, intuitively reflecting the polishing system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0184] 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.

[0185] 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 system based on laser tracker perception, 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 the location of an element to be polished. The magnetorheological polishing module is used to process the element to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, an electromagnet, a liquid pump, a position adjustment device and a current intensity controller. The magnetorheological mounting frame is installed on the tool end of the industrial robot. The current intensity controller, the position adjustment device, the nozzle and the electromagnet 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 electromagnet is used to change the stiffness of the magnetorheological fluid. The position adjustment device is used to adjust the position of the polishing wheel. The polishing wheel is used to process the test polishing element or the element to be polished. The current intensity controller is used to control the current flowing through the electromagnet and adjust the magnetic field strength of the electromagnet. 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 electromagnetic magnetic field strength according to the conversion relationship between the electromagnetic magnetic field strength and the polishing gap, or to adjust the polishing wheel position and the electromagnetic magnetic field strength at the same time according to the conversion relationship between the polishing wheel position and the polishing gap, so as to adjust the removal function and maintain the removal function of each polishing trajectory point constant when the distance error exceeds a set error range.

2. The magnetorheological polishing system based on laser tracker perception according to claim 1 is characterized in that: The position adjustment device 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 polishing wheel is connected to the connecting plate.

3. The magnetorheological polishing system 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.

4. A magnetorheological polishing method based on electromagnetic magnetic field intensity adjustment, implemented using the magnetorheological polishing system based on laser tracker sensing according to any one of claims 1 to 3, 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 electromagnetic magnetic field strength, fixed-point processing is performed on each processing point of the test polishing element, 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 electromagnetic magnetic field strength are fitted to obtain the conversion relationship between polishing gap and electromagnetic magnetic field strength. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, represents the strength of the electromagnet's magnetic field, Indicates the conversion relationship between the polishing gap and the magnetic field strength of the electromagnet; S3: The component to be polished is processed using a magnetorheological polishing system, and the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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; S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the electromagnetic magnetic field strength through the computer-controlled current intensity controller to change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

5. The magnetorheological polishing method based on electromagnetic magnetic field intensity adjustment according to claim 4 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 value of the electromagnetic magnetic field strength is set in the computer. , set the error range to , represents the maximum value of the distance error, then: when When , the intensity of the electromagnet magnetic field at the current polishing track point is kept unchanged; when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments: ； when And the electromagnetic magnetic field strength at the current polishing track point When the electromagnetic magnetic field strength at the current polishing track point is To make adjustments: ； in, Indicates the set initial magnetic field strength of the electromagnet.

6. The magnetorheological polishing method based on electromagnetic magnetic field intensity adjustment according to claim 4 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.

7. The magnetorheological polishing method based on electromagnetic magnetic field intensity adjustment according to claim 4 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.

8. A magnetorheological polishing method based on simultaneous adjustment of polishing wheel position and magnetic field intensity, implemented using the magnetorheological polishing system based on laser tracker sensing according to any one of claims 1 to 3, 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 position, 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 position are fitted to obtain the conversion relationship between polishing gap and polishing wheel position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the polishing wheel position, Indicates the conversion relationship between the polishing gap and the polishing wheel position; S3: The component to be polished is processed using a magnetorheological polishing system, and the actual Z-axis spatial coordinates of the target ball at each polishing trajectory point are measured in real time by a laser tracker, 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; S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the polishing wheel position and the electromagnetic magnetic field strength of the current polishing trajectory point unchanged; if exceeded, adjust the polishing wheel position through the computer-controlled position adjustment device, and at the same time control the current intensity controller to adjust the electromagnetic magnetic field strength, change the removal function of the current polishing trajectory point, and finally maintain the removal function of each polishing trajectory point constant.

9. The magnetorheological polishing method based on simultaneous adjustment of polishing wheel position and magnetic field intensity according to claim 8, 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 of the polishing wheel position is set in the computer , the maximum adjustment value of the electromagnetic magnetic field strength is , set the error range to , represents the maximum value of the distance error, then: when When the polishing wheel position at the current polishing track point is maintained and the electromagnetic magnetic field strength constant; when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments: ； ； Where r represents the distance between the electromagnet and the polishing wheel, M represents the magnetic moment, and k is the proportional coefficient; when And the polishing wheel position of the current polishing track point And the electromagnetic magnetic field strength at the current polishing track point When the polishing wheel position at the current polishing track point is calculated according to the following formula And the electromagnetic magnetic field strength at the current polishing track point To make adjustments: ； ； in, Indicates the set initial position of the polishing wheel. Indicates the set initial magnetic field strength of the electromagnet.

10. The magnetorheological polishing method based on simultaneous adjustment of polishing wheel position and magnetic field intensity according to claim 8, 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.

11. The magnetorheological polishing method based on simultaneous adjustment of polishing wheel position and magnetic field intensity according to claim 8, 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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