Magnetorheological polishing system and polishing method based on laser tracker perception

Abstract

The present invention relates to the field of magnetorheological polishing, and in particular to a magnetorheological polishing system and polishing method based on laser tracker sensing. The laser tracker is used to measure the real-time changes in the posture of the magnetorheological polishing system during processing, and the actuator output displacement adjustment, liquid pump height adjustment, or nozzle position adjustment are used to achieve real-time constant control of the removal function; or the removal function corresponding to the polishing gap of each polishing trajectory point is calculated and used as a processing parameter for the next processing, so that the change in the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change. The present invention does not require calibration of the measuring equipment and is not affected by the weight of the magnetorheological polishing system, the equipment's own operating accuracy, operating speed, posture, and other factors. During the optical polishing process, the posture changes of the polishing system can be measured in real time, intuitively reflecting the posture error of the polishing system. It 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 a polishing method thereof 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 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, an actuator group and a supply device. One end of the actuator group is connected to the magnetorheological mounting frame, and the other end of the actuator group is connected to the tool end of the industrial robot. The polishing wheel and the magnet are respectively mounted on the magnetorheological mounting frame. The nozzle is mounted on the magnetorheological mounting frame through a nozzle adjustment seat. The nozzle adjustment seat is used to adjust the position of 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. The supply device is arranged on one side of the polishing platform and is used to pump magnetorheological fluid into the nozzle.

[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 spatial coordinate and the theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point. The computer is also used to adjust the output displacement of the actuator group according to the conversion relationship between the output displacement of the actuator group and the polishing gap, or adjust the height of the supply device according to the conversion relationship between the height of the liquid pump and the polishing gap, or adjust the nozzle position according to the conversion relationship between the nozzle position and the polishing gap when the distance error exceeds a set error range, thereby adjusting the removal function to maintain the removal function of each polishing trajectory point constant; or the computer is used to calculate the removal function of each polishing trajectory point according to the conversion relationship between the removal function and the polishing gap, and input it as a new processing parameter into the industrial robot control instruction generation program, so that the change of the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

[0011] Furthermore, the supply device includes a liquid pump, a mounting bracket, a mounting plate, a linear guide and a ball screw stepper motor; wherein, the linear guide and the ball screw stepper motor are respectively vertically mounted on the mounting bracket, and the linear guides are distributed on both sides of the ball screw stepper motor, the liquid pump is mounted on the mounting plate, and the mounting plate is respectively connected to the slider of the linear guide and the nut of the ball screw stepper motor.

[0012] Furthermore, the nozzle is installed on the magnetorheological mounting frame through the nozzle adjustment seat, and the position of the nozzle relative to the polishing wheel is adjusted through the nozzle adjustment seat; the nozzle adjustment seat includes a fixing frame, a nozzle adjustment motor, a push plate, a nozzle mounting frame and an arc guide rail; wherein, the fixing frame is installed on the magnetorheological mounting frame, the nozzle adjustment motor and the arc guide rail are respectively installed on the fixing frame, the push plate is installed at the output end of the nozzle adjustment motor, the nozzle mounting frame is respectively connected to the push plate and the slider of the arc guide rail, and the nozzle is installed on the nozzle mounting frame.

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

[0014] A magnetorheological polishing method based on actuator adjustment is implemented using the magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0015] 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;

[0016] S2: Under different polishing gaps, by changing the output displacement of the actuator group, 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 actuator group output displacement are fitted to obtain the conversion relationship between the polishing gap and the actuator group output displacement. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the output displacement of the actuator group, It represents the conversion relationship between the polishing gap and the output displacement of the actuator group;

[0017] S3: Polishing the component to be polished using a magnetorheological polishing system, 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;

[0018] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the output displacement of the actuator group of the current polishing trajectory point unchanged; if exceeded, adjust the output displacement of the actuator group 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.

[0019] 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;

[0020] The maximum adjustment amount of the actuator group output displacement is set in the computer as , set the error range to , represents the maximum value of the distance error, then:

[0021] when When , the output displacement of the actuator group at the current polishing trajectory point remains unchanged;

[0022] when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments:

[0023] ;

[0024] when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments:

[0025] ;

[0026] in, Indicates the set initial output displacement of the actuator group.

[0027] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0028] 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.

[0029] 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:

[0030] 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;

[0031] 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.

[0032] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0033] 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:

[0034] ;

[0035] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0036] 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 :

[0037] ;

[0038] Where R represents the radius of the polishing wheel.

[0039] A magnetorheological polishing method based on liquid pump height adjustment is implemented using the magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0040] 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;

[0041] S2: Under different polishing gaps, by changing the liquid pump height, 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 height are fitted to obtain the conversion relationship between polishing gap and liquid pump height. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump height, Indicates the conversion relationship between the polishing gap and the liquid pump height;

[0042] S3: Polishing the component to be polished using a magnetorheological polishing system, 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;

[0043] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the liquid pump height of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump height by controlling the ball screw stepper 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.

[0044] 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;

[0045] The maximum adjustment amount of the liquid pump height is set in the computer. , set the error range to , represents the maximum value of the distance error, then:

[0046] when When , the height of the liquid pump at the current polishing track point is kept unchanged;

[0047] when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments:

[0048] ;

[0049] when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments:

[0050] ;

[0051] in, Indicates the set initial height of the liquid pump.

[0052] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0053] 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.

[0054] 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:

[0055] 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;

[0056] 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.

[0057] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0058] 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:

[0059] ;

[0060] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0061] 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 :

[0062] ;

[0063] Where R represents the radius of the polishing wheel.

[0064] A magnetorheological polishing method based on nozzle position adjustment is implemented using the magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0065] 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;

[0066] S2: Under different polishing gaps, by changing the nozzle 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 nozzle position are fitted to obtain the conversion relationship between polishing gap and nozzle position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the nozzle position, Indicates the conversion relationship between polishing gap and nozzle position;

[0067] S3: Polishing the component to be polished using a magnetorheological polishing system, 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;

[0068] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the nozzle position of the current polishing trajectory point unchanged; if exceeded, adjust the nozzle position by controlling the nozzle adjustment 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.

[0069] 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;

[0070] The maximum adjustment amount of the nozzle position set in the computer is , set the error range to , represents the maximum value of the distance error, then:

[0071] when When , the nozzle position of the current polishing trajectory point remains unchanged;

[0072] when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments:

[0073] ;

[0074] when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments:

[0075] ;

[0076] in, Indicates the set initial nozzle position.

[0077] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0078] 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.

[0079] 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:

[0080] 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;

[0081] 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.

[0082] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0083] 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:

[0084] ;

[0085] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0086] 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 :

[0087] ;

[0088] Where R represents the radius of the polishing wheel.

[0089] A magnetorheological polishing method based on removal function regulation is implemented using the magnetorheological polishing system based on laser tracker sensing, comprising the following steps:

[0090] 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;

[0091] S2: Perform fixed-point processing on each processing point of the test polishing element at different polishing gaps, calculate the volume removal rate of the removal function of each processing point at different polishing gaps, and perform data fitting on the discrete volume removal rate of the removal function and its corresponding removal function at different polishing gaps to obtain the conversion relationship between the polishing gap and the removal function. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Represents the removal function, Represents the conversion relationship between polishing gap and removal function;

[0092] S3: Use the magnetorheological polishing system to polish the component to be polished, use the laser tracker to measure the actual Z-axis spatial coordinates of the target ball at each polishing track point in real time, and calculate the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing track point and the theoretical Z-axis spatial coordinates ; Among them, 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;

[0093] S4: Set the error range in the computer to , Indicates the maximum value of the distance error, and judges whether the distance error of each polishing track point exceeds the set error range; if not, according to Calculate the removal function corresponding to the polishing trajectory point If exceeded, the distance error ,according to Removal function corresponding to polishing trajectory points ; The removal function corresponding to each polishing trajectory point The new processing parameters are input into the industrial robot control instruction generation program so that the change of the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

[0094] Furthermore, the process of establishing the measurement coordinate system of the laser tracker is as follows:

[0095] 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.

[0096] 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:

[0097] 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;

[0098] 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.

[0099] The measurement process of the spatial coordinates of the polishing wheel working point is:

[0100] 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:

[0101] ;

[0102] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0103] 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 :

[0104] ;

[0105] Where R represents the radius of the polishing wheel.

[0106] Compared to existing technologies, the present invention uses a laser tracker to measure the real-time changes in the position of the magnetorheological polishing system during the polishing process, and utilizes actuator output displacement adjustment, liquid pump height adjustment, or nozzle position adjustment to achieve real-time constant control of the removal function. Alternatively, the removal function corresponding to the polishing gap at each polishing trajectory point is calculated and input as a new processing parameter into the industrial robot control instruction generation program, ensuring that the change in the removal function at each polishing trajectory point matches the removal function caused by the actual polishing gap change, thereby achieving deterministic processing of the removal function. This method does not require calibration of measuring equipment such as force sensors and is unaffected by the weight of the magnetorheological polishing system, the equipment's own operating accuracy, operating speed, posture, 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 error, and has the advantages of low equipment cost and high measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] Figure 1A 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;

[0108] 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;

[0109] Figure 3 A schematic structural diagram of the actuator according to an embodiment of the present invention;

[0110] Figure 4 A schematic structural diagram of a supply device according to an embodiment of the present invention;

[0111] Figure 5 This is a schematic structural diagram of the nozzle adjustment seat described in an embodiment of the present invention.

[0112] Figure numerals: polishing platform 1, element to be polished 101, test polishing element 102, industrial robot 201, magnetorheological mounting frame 202, polishing wheel 203, magnet 204, nozzle 205, drive motor 206, active wheel 207, driven wheel 208, synchronous belt 209, transition plate 210, cylinder body 211, A cavity 212, B cavity 213, oil scraper ring 214, connecting plate 215, moving piston 216, liquid pump 217, mounting bracket 218, mounting plate 219, linear guide rail 220, ball screw stepper motor 221, fixing frame 222, nozzle adjustment motor 223, push plate 224, nozzle mounting frame 225, arc guide rail 226, actuator group 227, nozzle adjustment seat 228, laser tracker 3, target ball 301, computer 4. DETAILED DESCRIPTION

[0113] 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.

[0114] 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.

[0115] 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 posture during the polishing process. Various control methods (actuator output displacement adjustment, liquid pump height adjustment, and nozzle position adjustment) are used to achieve real-time stability of the removal function. Alternatively, the removal function corresponding to the polishing gap at each polishing trajectory point is calculated and input as a new processing parameter into the industrial robot control instruction generation program. This ensures that the change in the removal function at each polishing trajectory point matches the removal function caused by the actual polishing gap change, achieving deterministic machining of the removal function. This method does not require calibration of measurement equipment such as force sensors and is unaffected by the weight of the magnetorheological machining module, the equipment's own 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 error, and offers the advantage of high measurement accuracy.

[0116] The following describes in detail how to maintain the constancy of the removal function with reference to a specific embodiment.

[0117] In the first aspect, this embodiment provides a magnetorheological polishing system based on laser tracker sensing, the structure of the magnetorheological polishing system is as follows: Figure 1-Figure 5 Shown, including:

[0118] A polishing platform 1, on which a to-be-polished element 101 and a test polishing element 102 are arranged;

[0119] The polishing assembly includes an industrial robot 201 and a magnetorheological polishing module. The industrial robot 201 is used to drive the magnetorheological polishing module to move to the location of the test polishing element 102 or to drive the magnetorheological polishing module to move to the location of the element to be polished 101; the magnetorheological polishing module is used to polish the element to be polished 101 or the test polishing element 102; the magnetorheological polishing module includes a magnetorheological mounting frame 202, a polishing wheel 203, a magnet 204, a nozzle 205, an actuator group 227, a nozzle adjustment seat 228, a supply device and a polishing wheel driving device, one end of the actuator group 227 is connected to the magnetorheological mounting frame 202, and the other end of the actuator group 227 is connected to the industrial robot 201. The tool end of the robot 201 is connected, and the actuator group 227 is used to adjust the polishing gap. The magnetorheological mounting frame 202 is installed on the tool end of the industrial robot 201. The polishing wheel drive device is installed on the magnetorheological mounting frame 202 to drive the polishing wheel 203 to rotate and polish the polishing element 101 or the test polishing element 102. The nozzle 205 is installed on the magnetorheological mounting frame 202 through the nozzle adjustment seat 228 and is used to spray magnetorheological fluid onto the polishing wheel 203. The magnet 204 is used to change the stiffness of the magnetorheological fluid, and the nozzle adjustment seat 228 is used to adjust the position of the nozzle 205. The supply device is provided on one side of the polishing platform and is used to pump the magnetorheological fluid into the nozzle 205.

[0120] 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.

[0121] 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 output displacement of the actuator group 227 according to the conversion relationship between the output displacement of the actuator group 227 and the polishing gap, or adjust the height of the supply device according to the conversion relationship between the height of the liquid pump and the polishing gap, or adjust the position of the nozzle 205 according to the conversion relationship between the position of the nozzle 205 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; alternatively, computer 4 is used to calculate the removal function of each polishing trajectory point according to the conversion relationship between the removal function and the polishing gap, and input it as a new processing parameter into the control instruction generation program of the industrial robot 201, so that the change in the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

[0122] The polishing wheel drive device includes a driving motor 206, a driving wheel 207, a driven wheel 208, and a synchronous belt 209. The driving motor 206 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 208 is mounted on the bearing. The driving wheel 207 is mounted on the output end of the driving motor 206. The synchronous belt 209 is tensioned on the driven wheel 208 and the driving wheel 207. The polishing wheel 203 is driven to rotate by the driving motor 206. Please refer to the Chinese patent with a publication date of July 12, 2024 and publication number CN118322074A.

[0123] Actuator assembly 227 consists of two cascaded high-frequency actuators, with one high-frequency actuator mounted on the output of the other. This results in a total output displacement of actuator assembly 227 equal to the sum of the output displacements of the two high-frequency actuators. In this embodiment of the present invention, the high-frequency actuators are preferably SG-type hydrostatic linear cylinders manufactured by Jilin Huakong Testing Instrument Co., Ltd. Both high-frequency actuators have the same structure, including a transition plate 210, a cylinder body 211, a cavity A 212, a cavity B 213, an oil scraper ring 214, a connecting plate 215, and a moving piston 216. The transition plate 210 is used to connect the tool end of the industrial robot 201 and the cylinder body 211, the A cavity 212 and the B cavity 213 are used to control the inlet and outlet of the hydraulic oil, the oil scraper ring 214 is used to prevent the hydraulic oil from flowing out of the cylinder body 211, the moving piston 216 is used for position output, and the connecting plate 215 is used to connect the moving piston 216 with the magnetorheological polishing module or another high-frequency actuator, thereby outputting the displacement to the magnetorheological polishing module or another high-frequency actuator.

[0124] The supply device includes a liquid pump 217, a mounting bracket 218, a mounting plate 219, a linear guide 220, and a ball screw stepper motor 221. The linear guide 220 and the ball screw stepper motor 221 are vertically mounted on the mounting bracket 218, with the linear guides 220 located on either side of the ball screw stepper motor 221. The liquid pump 217 is mounted on the mounting plate 219, which is connected to the slider of the linear guide 220 and the nut of the ball screw stepper motor 221. The ball screw stepper motor 221 drives the liquid pump 217 to rise and fall vertically, adjusting its height relative to the polishing wheel 203. The liquid pump 217 uses a CFLC vertical multi-stage pump from Shanghai Dongfang Pump Industry Co., Ltd.

[0125] The nozzle adjustment base 228 includes a fixed frame 222, a nozzle adjustment motor 223, a push plate 224, a nozzle mounting frame 225, and an arcuate guide rail 226. The fixed frame 222 is mounted on the magnetorheological mounting frame 202 and has an L-shaped structure. The nozzle adjustment motor 223 and the arcuate guide rail 226 are respectively mounted on two perpendicular parts of the fixed frame 222, and the length direction of the arcuate guide rail 226 is the extension and contraction direction of the nozzle adjustment motor 223. The push plate 224 is mounted on the output end of the nozzle adjustment motor 223. One end of the nozzle mounting frame 225 is connected to the push plate 224 and the slider of the arcuate guide rail 226 respectively, and the other end of the nozzle mounting frame 225 is used to mount the nozzle 205. The nozzle adjustment motor 223 drives the nozzle 205 to move, thereby adjusting the distance between the nozzle 205 and the polishing wheel 203.

[0126] 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.

[0127] 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 operating 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 moving state, and the measured motion posture is compared with the theoretical posture data to obtain posture error information. The measured motion posture is calculated to obtain polishing gap change data, and then the removal function change data is obtained. Finally, the removal function change is controlled by adjusting the output displacement of the actuator group 227 or the height of the liquid pump 217 or the position of the nozzle 205 to achieve the desired control parameters, ultimately achieving the purpose of maintaining a constant removal function for each polishing point; or, based on the conversion relationship between the removal function and the polishing gap, the removal function of each polishing trajectory point is calculated and input as a new processing parameter into the control instruction generation program of the industrial robot 201, so that the removal function change of each polishing trajectory point is consistent with the removal function change caused by the actual polishing gap change.

[0128] In a second aspect, this embodiment further provides a magnetorheological polishing method based on actuator adjustment, which is implemented using the magnetorheological polishing system based on laser tracker sensing, and includes the following steps:

[0129] 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.

[0130] The process of establishing the laser tracker measurement coordinate system is:

[0131] 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.

[0132] 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:

[0133] 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.

[0134] 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, and the spatial coordinates of the target ball corresponding to each posture measurement are (x1, y1, z1).

[0135] 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 .

[0136] 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:

[0137] ;

[0138] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0139] 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:

[0140] ;

[0141] Where R is the radius of the polishing wheel.

[0142] 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 .

[0143] 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:

[0144] .

[0145] 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.

[0146] S2: Under different polishing gaps, by changing the output displacement of the actuator group, 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 actuator group output displacement are fitted to obtain the conversion relationship between the polishing gap and the actuator group output displacement. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the output displacement of the actuator group, It represents the conversion relationship between the polishing gap and the output displacement of the actuator group.

[0147] The present invention realizes the change adjustment of the removal function by adjusting the output displacement of the actuator group. The operation for determining the relationship between the output displacement of the actuator group and the change of the removal function is as follows:

[0148] 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 output displacement of the actuator group at each processing point was different. The volume removal rate of the removal function of 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 output displacement of the actuator group, 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 output displacement of the actuator group. This conversion relationship can be expressed as: .

[0149] 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.

[0150] S3: The component to be polished is polished using a magnetorheological polishing system. 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.

[0151] 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.

[0152] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the output displacement of the actuator group of the current polishing trajectory point unchanged; if exceeded, adjust the output displacement of the actuator group 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.

[0153] By adjusting the output displacement of the actuator group, the removal function change adjustment is achieved. 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 system meets the requirements of high-precision machining and maintains the output displacement of the current actuator group 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 of the current polishing trajectory point and the output displacement of the actuator group The output displacement of the actuator group is calculated based on the set theoretical removal function volume removal rate, and the output displacement of the actuator group is sent to the actuator group through a computer. Finally, the change of the removal function is controlled by adjusting the output displacement of the actuator group to achieve trajectory error control of the magnetorheological polishing system.

[0154] 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.

[0155] The maximum adjustment amount of the actuator group output displacement is set in the computer as , set the error range to , represents the maximum value of the distance error, then:

[0156] when When , the output displacement of the actuator group at the current polishing trajectory point remains unchanged;

[0157] when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments:

[0158] ;

[0159] when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments:

[0160] ;

[0161] in, Indicates the set initial output displacement of the actuator group.

[0162] Calculate the maximum displacement output by the actuator group The time required to control the magnetorheological processing module :

[0163] ;

[0164] in, Indicates the output control rate of the actuator group;

[0165] 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 ;

[0166] ;

[0167] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0168] ;

[0169] in, Indicates the distance between two adjacent polishing track points.

[0170] 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 .

[0171] 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.

[0172] 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 utilizes displacement regulation of the actuator group's output 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 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, providing a direct reflection of the system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0173] In a third aspect, this embodiment further provides a magnetorheological polishing method based on liquid pump height adjustment, which is implemented using the above-mentioned magnetorheological polishing system based on laser tracker perception, and includes the following steps:

[0174] 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.

[0175] The process of establishing the laser tracker measurement coordinate system is:

[0176] 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.

[0177] 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:

[0178] 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.

[0179] 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 .

[0180] 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:

[0181] ;

[0182] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0183] 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:

[0184] ;

[0185] Where R is the radius of the polishing wheel.

[0186] 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 .

[0187] 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:

[0188] .

[0189] 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.

[0190] S2: Under different polishing gaps, by changing the liquid pump height, 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 height are fitted to obtain the conversion relationship between polishing gap and liquid pump height. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump height, Indicates the conversion relationship between the polishing gap and the liquid pump height.

[0191] The present invention realizes the change adjustment of the removal function by adjusting the height of the liquid pump. The operation for determining the relationship between the liquid pump speed and the change of the removal function is as follows:

[0192] An industrial robot was used to drive the tool end to perform fixed-point processing at different locations on the surface of the test polishing element at different polishing gaps for a period of time. The liquid pump height 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 liquid pump height, 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 height. This conversion relationship can be expressed as: .

[0193] 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.

[0194] 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 polishing wheel position (LW) for polishing gaps of 1mm and 2mm corresponds to a 1.6mm polishing gap. In this case, the 2mm volumetric removal rate (MRR) is used to calculate the relationship between the polishing gap and the liquid pump height.

[0195] S3: The component to be polished is polished using a magnetorheological polishing system. 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.

[0196] 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.

[0197] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the liquid pump height of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump height by controlling the ball screw stepper 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.

[0198] The removal function can be adjusted by adjusting the height of the liquid pump. 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 system meets the requirements of high-precision processing and maintains the current liquid pump height 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 liquid pump height The liquid pump height 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 liquid pump height to achieve trajectory error control of the magnetorheological polishing system.

[0199] 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.

[0200] The maximum adjustment amount of the liquid pump height is set in the computer. , set the error range to , represents the maximum value of the distance error, then:

[0201] when When , the height of the liquid pump at the current polishing track point is kept unchanged;

[0202] when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments:

[0203] ;

[0204] when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments:

[0205] ;

[0206] in, Indicates the set initial height of the liquid pump.

[0207] Calculate the maximum adjustment amount at the liquid pump height |∆SP max |, the time required to control the magnetorheological processing module :

[0208] ;

[0209] in, The maximum adjustment rate for the liquid pump height.

[0210] 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 ;

[0211] ;

[0212] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0213] ;

[0214] in, Indicates the distance between two adjacent polishing track points.

[0215] 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 .

[0216] 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.

[0217] 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 utilizes height adjustment of a liquid pump 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 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, providing a direct reflection of the polishing system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0218] In a fourth aspect, this embodiment further provides a magnetorheological polishing method based on nozzle position adjustment, which is implemented using the magnetorheological polishing system based on laser tracker sensing, and includes the following steps:

[0219] 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.

[0220] The process of establishing the laser tracker measurement coordinate system is:

[0221] 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.

[0222] 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:

[0223] 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.

[0224] 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 .

[0225] 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:

[0226] ;

[0227] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0228] 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:

[0229] ;

[0230] Where R is the radius of the polishing wheel.

[0231] 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 .

[0232] 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:

[0233] .

[0234] 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.

[0235] S2: Under different polishing gaps, by changing the nozzle 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 nozzle position are fitted to obtain the conversion relationship between polishing gap and nozzle position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the nozzle position, Indicates the conversion relationship between polishing gap and nozzle position.

[0236] The present invention realizes the change adjustment of the removal function by adjusting the nozzle position. The operation for determining the relationship between the nozzle position and the change of the removal function is as follows:

[0237] 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 nozzle 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 nozzle 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 nozzle position. This conversion relationship can be characterized as follows: .

[0238] 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.

[0239] 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 nozzle position.

[0240] S3: The component to be polished is polished using a magnetorheological polishing system. 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.

[0241] 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.

[0242] S4: Determine whether the distance error of each polishing trajectory point exceeds the set error range; if not, keep the nozzle position of the current polishing trajectory point unchanged; if exceeded, adjust the nozzle position by controlling the nozzle adjustment 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.

[0243] By adjusting the nozzle position, the removal function can be adjusted. During the polishing process of the component to be polished, 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 system meets the requirements of high-precision processing and maintains the current nozzle position 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 nozzle position at the current polishing track point The nozzle position is calculated based on the set theoretical removal function volume removal rate and sent to the nozzle adjustment motor through the computer. Finally, the change of the removal function is regulated by adjusting the nozzle position to achieve trajectory error control of the magnetorheological polishing system.

[0244] 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.

[0245] The maximum adjustment amount of the nozzle position set in the computer is , set the error range to , represents the maximum value of the distance error, then:

[0246] when When , the nozzle position of the current polishing trajectory point remains unchanged;

[0247] when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments:

[0248] ;

[0249] when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments:

[0250] ;

[0251] in, Indicates the set initial nozzle position.

[0252] Calculate the adjustment amount at the nozzle position as the maximum value |∆NL max |, the time required to control the magnetorheological processing module :

[0253] ;

[0254] in, The maximum adjustment rate of the nozzle position.

[0255] 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 ;

[0256] ;

[0257] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0258] ;

[0259] in, Indicates the distance between two adjacent polishing track points.

[0260] 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. .

[0261] 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.

[0262] 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 utilizes nozzle position 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 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, providing a direct reflection of the polishing system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0263] In a fifth aspect, this embodiment further provides a magnetorheological polishing method based on removal function adjustment, which is implemented using the magnetorheological polishing system based on laser tracker sensing, and includes the following steps:

[0264] 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.

[0265] The process of establishing the laser tracker measurement coordinate system is:

[0266] 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.

[0267] 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:

[0268] 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.

[0269] 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 .

[0270] 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:

[0271] ;

[0272] Among them, a, b, and c are the normal vectors of the line, which are obtained through the teaching pendant of the industrial robot;

[0273] 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:

[0274] ;

[0275] Where R is the radius of the polishing wheel.

[0276] 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 .

[0277] 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:

[0278] .

[0279] 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.

[0280] S2: Perform fixed-point processing on each processing point of the test polishing element at different polishing gaps, calculate the volume removal rate of the removal function of each processing point at different polishing gaps, and perform data fitting on the discrete volume removal rate of the removal function and its corresponding removal function at different polishing gaps to obtain the conversion relationship between the polishing gap and the removal function. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Represents the removal function, Represents the conversion relationship between polishing gap and removal function.

[0281] The present invention calculates the corresponding change of the removal function during the processing by using the polishing gap change information, and uses the changed removal function set as the input of the next processing to achieve deterministic processing of the removal function. Since the posture error of the magnetorheological polishing system is small, the posture error ±∆d i It can be regarded as the change of the polishing gap of the magnetorheological polishing system. In order to compensate for the change of the removal function caused by the polishing gap trajectory error, it is necessary to determine the relationship between the polishing gap and the change of the removal function. The operation is as follows: fixed-point processing is performed at different positions on the surface of the test polishing element for a period of time with different polishing gaps, and the volume removal rate of the removal function of each processing point is calculated. Based on the discrete removal function volume removal rate and its corresponding polishing gap data, the Polyfit command of Matlab (this command is a basic general command of Matlab software) is used to fit the data to obtain the conversion relationship between the polishing gap and the removal function. This conversion relationship can be characterized as: .

[0282] According to the conversion relationship between the polishing gap and the removal function, the polishing gap of each processing point in the processing process is calculated The corresponding removal function , get the set of variable removal functions , will change the removal function set As new processing parameters The input is into the industrial robot control instruction generation program, so that the removal function change of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change, ensuring that the actual processing process utilizes the certainty of the removal function change to achieve high-precision processing goals.

[0283] S3: Use the magnetorheological polishing system to polish the component to be polished, use the laser tracker to measure the actual Z-axis spatial coordinates of the target ball at each polishing track point in real time, and calculate the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing track point and the theoretical Z-axis spatial coordinates ; Among them, 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.

[0284] 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 error range of the set distance error. Indicates the maximum value of the distance error.

[0285] S4: Set the error range in the computer to , Indicates the maximum value of the distance error, and judges whether the distance error of each polishing track point exceeds the set error range; if not, according to Calculate the removal function corresponding to the polishing trajectory point If exceeded, the distance error ,according to Removal function corresponding to polishing trajectory points ; The removal function corresponding to each polishing trajectory point The new processing parameters are input into the industrial robot control instruction generation program so that the change of the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

[0286] 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 ;

[0287] ;

[0288] Calculate the maximum speed of the magnetorheological machining module The minimum moving time between two adjacent polishing track points :

[0289] ;

[0290] in, Indicates the distance between two adjacent polishing track points.

[0291] 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 .

[0292] 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. After the machining is completed, the measured posture error information is used to solve the change of the polishing gap and calculate the corresponding change of the removal function. In the next machining, the variable removal function set is used as the input of the machining parameters. Without compensating for the operating posture error of the magnetorheological polishing system, deterministic machining of the removal function is realized, and ultimately high-precision machining goals are achieved.

[0293] 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 utilizes displacement regulation of the actuator group's output 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 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, providing a direct reflection of the system's posture errors. This method offers the advantages of low equipment cost and high measurement accuracy.

[0294] 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.

[0295] 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 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, an actuator group and a supply device. One end of the actuator group is connected to the magnetorheological mounting frame, and the other end of the actuator group is connected to the tool end of the industrial robot. The polishing wheel and the magnet are respectively mounted on the magnetorheological mounting frame. The nozzle is mounted on the magnetorheological mounting frame through a nozzle adjustment seat. The nozzle adjustment seat is used to adjust the position of 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. The supply device is arranged on one side of the polishing platform and is used to pump magnetorheological fluid into the nozzle. 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; a computer for calculating a distance error between an actual Z-axis spatial coordinate and a theoretical Z-axis spatial coordinate of the target ball at each polishing trajectory point; and further for adjusting the output displacement of the actuator group according to a conversion relationship between the output displacement of the actuator group and the polishing gap, adjusting the height of the supply device according to a conversion relationship between the height of the liquid pump and the polishing gap, or adjusting the position of the nozzle according to a conversion relationship between the position of the nozzle and the polishing gap, when the distance error exceeds a set error range, thereby adjusting the removal function to maintain a constant removal function at each polishing trajectory point; Alternatively, a computer is used to calculate the removal function of each polishing trajectory point based on the conversion relationship between the removal function and the polishing gap, and input it into the industrial robot control instruction generation program as a new processing parameter, so that the change of the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

2. The magnetorheological polishing system based on laser tracker perception according to claim 1 is characterized in that: The supply device includes a liquid pump, a mounting bracket, a mounting plate, a linear guide and a ball screw stepper motor; wherein, the linear guide and the ball screw stepper motor are respectively vertically mounted on the mounting bracket, and the linear guides are distributed on both sides of the ball screw stepper motor, the liquid pump is mounted on the mounting plate, and the mounting plate is respectively connected to the slider of the linear guide and the nut of the ball screw stepper motor.

3. The magnetorheological polishing system based on laser tracker perception according to claim 1 is characterized in that: The nozzle is installed on the magnetorheological mounting frame through the nozzle adjustment seat, and the position of the nozzle relative to the polishing wheel is adjusted through the nozzle adjustment seat; the nozzle adjustment seat includes a fixing frame, a nozzle adjustment motor, a push plate, a nozzle mounting frame and an arc guide rail; wherein, the fixing frame is installed on the magnetorheological mounting frame, the nozzle adjustment motor and the arc guide rail are respectively installed on the fixing frame, the push plate is installed at the output end of the nozzle adjustment motor, the nozzle mounting frame is respectively connected to the push plate and the slider of the arc guide rail, and the nozzle is installed on the nozzle mounting frame.

4. 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 driving motor, a motor connecting plate, a driving wheel, a driven wheel and a synchronous belt. The driving motor is installed on the connecting plate, a bearing seat is installed on the connecting plate, a bearing is installed in the bearing seat, the bearing is connected to the polishing wheel, the driven wheel is mounted on the bearing, the driving wheel is mounted on the output end of the driving motor, and the synchronous belt is tensioned on the driven wheel and the driving wheel.

5. A magnetorheological polishing method based on actuator adjustment, implemented using the magnetorheological polishing system based on laser tracker sensing according to any one of claims 1 to 4, 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 output displacement of the actuator group, 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 actuator group output displacement are fitted to obtain the conversion relationship between the polishing gap and the actuator group output displacement. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the output displacement of the actuator group, It represents the conversion relationship between the polishing gap and the output displacement of the actuator group; S3: Polishing the component to be polished using a magnetorheological polishing system, 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 output displacement of the actuator group of the current polishing trajectory point unchanged; if exceeded, adjust the output displacement of the actuator group 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.

6. The magnetorheological polishing method based on actuator adjustment according to claim 5, 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 actuator group output displacement is set in the computer as , set the error range to , represents the maximum value of the distance error, then: when When , the output displacement of the actuator group at the current polishing trajectory point remains unchanged; when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments: ； when And the actuator group output displacement of the current polishing trajectory point When the actuator group output displacement of the current polishing trajectory point is To make adjustments: ； in, Indicates the set initial output displacement of the actuator group.

7. The magnetorheological polishing method based on actuator adjustment according to claim 5, 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.

8. The magnetorheological polishing method based on actuator adjustment according to claim 5, 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.

9. A magnetorheological polishing method based on liquid pump height adjustment, implemented using the magnetorheological polishing system 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 liquid pump height, 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 height are fitted to obtain the conversion relationship between polishing gap and liquid pump height. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the liquid pump height, Indicates the conversion relationship between the polishing gap and the liquid pump height; S3: Polishing the component to be polished using a magnetorheological polishing system, 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 height of the current polishing trajectory point unchanged; if exceeded, adjust the liquid pump height by controlling the ball screw stepper 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.

10. The magnetorheological polishing method based on liquid pump height adjustment according to claim 9, 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 height is set in the computer. , set the error range to , represents the maximum value of the distance error, then: when When , the height of the liquid pump at the current polishing track point is kept unchanged; when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments: ； when And the liquid pump height at the current polishing track point When the liquid pump height at the current polishing track point is To make adjustments: ； in, Indicates the set initial height of the liquid pump.

11. The magnetorheological polishing method based on liquid pump height adjustment according to claim 9, 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.

12. The magnetorheological polishing method based on liquid pump height adjustment according to claim 9, 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.

13. A magnetorheological polishing method based on nozzle position adjustment, implemented using the magnetorheological polishing system based on laser tracker perception according to claim 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 nozzle 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 nozzle position are fitted to obtain the conversion relationship between polishing gap and nozzle position. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Indicates the nozzle position, Indicates the conversion relationship between polishing gap and nozzle position; S3: Polishing the component to be polished using a magnetorheological polishing system, 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 nozzle position of the current polishing trajectory point unchanged; if exceeded, adjust the nozzle position by controlling the nozzle adjustment 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.

14. The magnetorheological polishing method based on nozzle position adjustment according to claim 13, 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 nozzle position set in the computer is , set the error range to , represents the maximum value of the distance error, then: when When , the nozzle position of the current polishing trajectory point remains unchanged; when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments: ； when And the nozzle position of the current polishing trajectory point When the nozzle position of the current polishing track point is calculated according to the following formula To make adjustments: ； in, Indicates the set initial nozzle position.

15. The magnetorheological polishing method based on nozzle position adjustment according to claim 13, 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.

16. The magnetorheological polishing method based on nozzle position adjustment according to claim 13, 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.

17. A magnetorheological polishing method based on removal function regulation, implemented using the magnetorheological polishing system based on laser tracker perception according to any one of claims 1 to 4, 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: Perform fixed-point processing on each processing point of the test polishing element at different polishing gaps, calculate the volume removal rate of the removal function of each processing point at different polishing gaps, and perform data fitting on the discrete volume removal rate of the removal function and its corresponding removal function at different polishing gaps to obtain the conversion relationship between the polishing gap and the removal function. ;in, Represents the polishing gap corresponding to the volume removal rate of each removal function, Represents the removal function, Represents the conversion relationship between polishing gap and removal function; S3: Use the magnetorheological polishing system to polish the component to be polished, use the laser tracker to measure the actual Z-axis spatial coordinates of the target ball at each polishing track point in real time, and calculate the distance error between the actual Z-axis spatial coordinates of the target ball at each polishing track point and the theoretical Z-axis spatial coordinates ; Among them, 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; S4: Set the error range in the computer to , Indicates the maximum value of the distance error, and judges whether the distance error of each polishing track point exceeds the set error range; if not, according to Calculate the removal function corresponding to the polishing trajectory point If exceeded, the distance error ,according to Removal function corresponding to polishing trajectory points ; The removal function corresponding to each polishing trajectory point The new processing parameters are input into the industrial robot control instruction generation program so that the change of the removal function of each polishing trajectory point is consistent with the removal function caused by the actual polishing gap change.

18. The magnetorheological polishing method based on removal function adjustment according to claim 17, 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.

19. The magnetorheological polishing method based on removal function regulation according to claim 17, 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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