Magnetorheological machining regulation and control device based on instantaneous current sensing and machining method thereof

Abstract

The invention relates to the technical field of magneto-rheological, in particular to a magneto-rheological machining regulation and control device based on instantaneous current perception and a machining method thereof.The device comprises a polishing platform, a polishing assembly, a detection circuit and a computer, and operation parameters of the polishing assembly comprise the magnetic field intensity of an electromagnet and the position of a polishing wheel; when the polishing assembly is used for polishing a test polishing element, the corresponding relation between different operation parameters of the polishing assembly and the ideal instantaneous current is collected, when the element to be polished is polished, the second instantaneous current is judged through the corresponding relation, and whether the operation parameters are adjusted or not is determined according to the judgment result. The operation parameters are adjusted in real time, the step of calibrating the parameters such as gravity compensation is not needed in the process, the precision of measured data is only limited by the current measurement precision of the second instantaneous current between the magneto-rheological polishing module and the to-be-polished element, the measurement result is more accurate, a force sensor does not need to be added, and the equipment cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetorheological technology, and particularly relates to a magnetorheological processing control device based on instantaneous current sensing and a processing method thereof. Background Art

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

[0003] At present, the force-position control method has gradually become a new type of constant force regulation and polishing control method for robots. A common application method is to place a force sensor between the processing tool and the robot. First, the gravity of the force sensor is calibrated to ensure the accuracy of the measurement. The pose error is calculated by measuring the change of force, and then the robot pose error is compensated by means of the robot body or other motion compensation mechanisms to achieve constant force control. The high-efficiency processing of large-diameter optical elements relies on the magnetorheological processing equipment of large-size polishing wheels, and the weight of the magnetorheological processing module of large-size polishing wheels is generally hundreds of kilograms. However, for a magnetorheological processing module weighing hundreds of kilograms, the force change caused by the robot pose error is only dozens of Newtons. When performing high-precision processing, the force needs to be constant at several Newtons or even a fraction of a Newton, which requires the absolute measurement accuracy of measuring equipment such as force sensors to reach one ten-thousandth, and the force sensor also needs to be in a state of variable speed and variable pose motion. Force sensors that meet these requirements are often extremely expensive, greatly increasing the cost of the equipment. Summary of the Invention

[0004] To solve the above problems, the present invention provides a magnetorheological processing regulation device and its processing method based on instantaneous current sensing, so as to solve the problem that the regulation of the polishing wheel in the prior art requires data collection by means of a high-precision force sensor, and the high-precision force sensor has a high cost.

[0005] To achieve the above object, the technical solution of the present invention is realized as follows: A magnetorheological processing regulation device based on instantaneous current sensing, comprising: A polishing platform, on which an element to be polished and a test polishing element are arranged; A polishing assembly, including an industrial robot and a magnetorheological polishing module. The industrial robot is used to drive the magnetorheological polishing module to move to the position where the test polishing element is located or the position where the element to be polished is located; the magnetorheological polishing module is used to process the element to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, an electromagnet, a liquid pump, a position adjustment mechanism, and a current intensity controller. The magnetorheological mounting frame is installed at the tool end of the industrial robot. The current intensity controller, the position adjustment mechanism, the nozzle, and the electromagnet are respectively installed on the magnetorheological mounting frame. The liquid pump is arranged on the industrial robot or on one side of the industrial robot. The liquid pump is used to pump magnetorheological fluid into the nozzle. The nozzle is used to spray magnetorheological fluid onto the polishing wheel. The electromagnet is used to change the stiffness of the magnetorheological fluid. The position adjustment mechanism is used to adjust the position of the polishing wheel. The polishing wheel is used to process the test polishing element or the element to be polished. The current intensity controller is used to control the energizing current of the electromagnet and adjust the magnetic field strength of the electromagnet; the operating parameters of the magnetorheological polishing module include the magnetic field strength of the electromagnet and the position of the polishing wheel; A detection circuit is used to output a constant voltage, form a first closed loop when the magnetorheological polishing module contacts the surface of the test polishing element, and detect the first instantaneous current in the first closed loop in real time, or form a second closed loop when the magnetorheological polishing module contacts the surface of the element to be polished, and detect the second instantaneous current in the second closed loop in real time; A computer is used to calculate the corresponding relationship between the operating parameters of the magnetorheological polishing module and the ideal instantaneous current according to the polishing data. The polishing data includes the first instantaneous current data detected by the detection circuit under different operating parameters of the magnetorheological polishing module; and the computer is used to adjust the current operating parameters when it is determined that the error between the second instantaneous current detected by the detection circuit and the ideal instantaneous current corresponding to the current operating parameters exceeds the preset error range, so that the error between the second instantaneous current detected by the detection circuit after the operating parameters are adjusted and the corresponding ideal instantaneous current is within the preset error range.

[0006] Further, the position adjustment mechanism includes a support fixing frame, a ball screw stepping motor, and a connecting plate. The ball screw stepping motor is installed on the magnetorheological mounting frame through the support fixing frame. The nut of the ball screw stepping motor is fixedly connected to the connecting plate. The polishing wheel and the magnet are both installed on the connecting plate.

[0007] Further, the magnetorheological polishing module further includes a polishing wheel driving mechanism. The polishing wheel driving mechanism includes a driving motor, 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 sleeved on the bearing. The driving wheel is sleeved on the output end of the driving motor. The synchronous belt is tensioned between the driven wheel and the driving wheel.

[0008] A magnetorheological processing control method based on magnetic field strength adjustment is realized by using the above-mentioned magnetorheological processing control device based on instantaneous current sensing. The magnetorheological processing control method includes the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different electromagnetic field strengths of the electromagnet to process the test polishing element. The detection circuit detects the first instantaneous current in the first closed loop in real time, and obtains the corresponding relationship between the liquid pump height and the first instantaneous current , represents the first instantaneous current, represents the electromagnetic field strength of the electromagnet, represents the conversion relationship between the electromagnetic field strength of the electromagnet and the first instantaneous current. Map and store multiple groups of first instantaneous currents and the corresponding electromagnetic field strengths of the electromagnets to obtain polishing data. The computer calculates the corresponding relationship between the electromagnetic field strength of the electromagnet and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current electromagnet magnetic field strength exceeds the preset error range, the current intensity controller is used to adjust the electromagnet magnetic field strength so that the error between the second instantaneous current detected by the detection circuit after the adjustment of the electromagnet magnetic field strength and the corresponding ideal instantaneous current is within the preset error range.

[0009] Further, record the sampling period for the detection circuit to collect the second instantaneous current as , and record the shortest time required to adjust the electromagnet magnetic field strength to the maximum adjustment amount as , , , and record the shortest switching time between two adjacent processing trajectory points on the element to be polished as , ; where is the fastest adjustment speed of the electromagnet magnetic field strength change, is the highest moving speed of the industrial robot, represents the distance between two adjacent processing trajectory points on the element to be polished; The adjustment method for the sampling frequency of the detection circuit includes: Judge whether the relationship between , , satisfies the formula: ; If not, adjust the sampling frequency for the detection circuit to collect the second instantaneous current until the formula is satisfied, and the sampling frequency is .

[0010] Further, the current intensity controller adjusts the electromagnet magnetic field strength at the current processing trajectory point, including: If the second instantaneous current does not exceed the allowable change range , do not control the motor of the liquid pump and keep the electromagnet magnetic field strength at the current processing trajectory point unchanged; If the second instantaneous current exceeds the allowable change range and |A i | < |A0 ± ΔA max |, then adjust the electromagnet magnetic field strength at the current processing trajectory point according to the following formula: ; Where represents the ideal instantaneous current value, represents the adjustment range of the second instantaneous current; If the second instantaneous current exceeds the allowable change range and |A i | > |A0 ± ΔA max |, then the electromagnetic field strength of the current machining trajectory point is adjusted according to the following formula as follows: ; wherein, represents the set initial electromagnetic field strength of the electromagnet.

[0011] A magnetorheological machining control method based on simultaneous adjustment of the polishing wheel position and the magnetic field strength is realized by using the above-mentioned magnetorheological machining control device based on instantaneous current sensing. The magnetorheological machining control method is characterized by comprising the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different polishing wheel positions to machine the test polishing element, and the detection circuit detects the first instantaneous current in the first closed loop in real time to obtain the corresponding relationship between the polishing wheel position and the first instantaneous current , represents the first instantaneous current, represents the polishing wheel position, represents the conversion relationship between the polishing wheel position and the first instantaneous current. Multiple groups of first instantaneous currents and the corresponding polishing wheel positions are mapped and stored to obtain polishing data. The computer calculates the corresponding relationship between the polishing wheel position and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current polishing wheel position exceeds the preset error range, the polishing wheel position is adjusted by the ball screw stepping motor and the electromagnetic field strength of the electromagnet is adjusted by the current intensity controller, so that the error between the second instantaneous current detected by the detection circuit after the adjustment of the polishing wheel position and the electromagnetic field strength of the electromagnet and the corresponding ideal instantaneous current is within the preset error range.

[0012] Further, the sampling period for the detection circuit to collect the second instantaneous current is denoted as , and the shortest time required to adjust the polishing wheel position to the maximum adjustment amount is denoted as , , and the shortest time required to adjust the electromagnetic field strength of the electromagnet to the maximum adjustment amount is denoted as , , denote the shortest switching time between two adjacent machining trajectory points on the element to be polished as , ; among them, is the fastest adjustment speed of the polishing wheel position change, is the fastest adjustment speed of the electromagnetic field strength change of the electromagnet, is the highest moving speed of the industrial robot, represents the distance between two adjacent machining trajectory points on the element to be polished; The adjustment method of the sampling frequency of the detection circuit includes: Judge whether the relationship between , , , satisfies the formula: ; If not, adjust the sampling frequency of the detection circuit for collecting the second instantaneous current until the formula is satisfied, and the sampling frequency is .

[0013] Further, adjust the polishing wheel position of the current machining trajectory point through the ball screw stepping motor and adjust the electromagnetic field strength of the electromagnet at the current machining trajectory point through the current intensity controller, including: If the second instantaneous current does not exceed the allowable change range , do not control the ball screw stepping motor and the current intensity controller, and keep the polishing wheel position and the electromagnetic field strength of the current machining trajectory point unchanged; If the second instantaneous current exceeds the allowable change range and , then adjust the polishing wheel position and the electromagnetic field strength of the current machining trajectory point according to the following formula: ; ; Among them, represents the ideal instantaneous current value, represents the adjustment amplitude of the second instantaneous current, represents the change amount of the polishing wheel position, represents the distance between the electromagnet and the working point of the polishing wheel, represents the magnetic moment, is the proportional coefficient; If the second instantaneous current exceeds the allowable change range and at this time, then the position of the polishing wheel at the current machining trajectory point and the electromagnetic field strength of the electromagnet are adjusted according to the following formula: ; ; wherein, represents the set initial position of the polishing wheel, represents the set initial electromagnetic field strength of the electromagnet.

[0014] Compared with the prior art, the present invention can achieve the following beneficial effects: When using the magnetorheological polishing module to polish the polishing test piece, different operating parameters of the magnetorheological polishing module and the corresponding first instantaneous current are collected, and then the corresponding relationship between the operating parameters and the ideal instantaneous current is calculated through the collected operating parameters and the first instantaneous current. After that, the second instantaneous current is judged through this relationship, and whether to adjust the operating parameters of the magnetorheological polishing module is decided according to the judgment result, so as to realize the real-time adjustment of the electromagnetic field strength of the electromagnet or the real-time adjustment of the polishing wheel position and the electromagnetic field strength of the electromagnet, so that the flow rate fluctuation of the magnetorheological fluid at each machining trajectory point meets the requirements of high-precision polishing and ensures the constancy of the removal function. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the operating accuracy, operating speed, posture, inertia and other factors of the equipment itself. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current between the magnetorheological polishing module and the polishing test piece to be measured. The measurement result is more accurate, and there is no need to add equipment such as high-precision force sensors, reducing the equipment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the magnetorheological processing control device based on instantaneous current sensing according to an embodiment of the present invention from one perspective; Figure 2 is a schematic structural diagram of the magnetorheological processing control device based on instantaneous current sensing according to an embodiment of the present invention from another perspective; Figure 3 is a schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention from one perspective; Figure 4 is a schematic structural diagram of the magnetorheological polishing module according to an embodiment of the present invention from another perspective; Figure 5Schematic structural diagram of the position adjustment mechanism according to the embodiment of the present invention.

[0016] Reference numerals: polishing platform 1, element to be polished 101, test polishing element 102, industrial robot 201, magnetorheological mounting bracket 202, polishing wheel 203, electromagnet 204, nozzle 205, liquid pump 206, support fixing bracket 207, ball screw stepping motor 208, connecting plate 209, drive motor 210, driving wheel 211, driven wheel 212, synchronous belt 213, lead screw 214, guide rail 215, slider 216, nut 217, current intensity controller 218, mounting plate 219, support frame 220, computer 3. Detailed implementation manners

[0017] In the following, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are denoted by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, their detailed descriptions will not be repeated.

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0019] In a first aspect, the present embodiment provides a magnetorheological processing control device based on instantaneous current sensing. The structure of the device is as Figures 1-5 shown and includes: A polishing platform 1, on which an element to be polished 101 and a test polishing element 102 are arranged; A polishing assembly, which includes an industrial robot 201 and a magnetorheological polishing module. The industrial robot 201 is used to drive the magnetorheological polishing module to move to the position where the test polishing element 102 is located or drive the magnetorheological polishing module to move to the position where the element to be polished 101 is located. The magnetorheological polishing module is used to process the element to be polished 101 or the test polishing element 102. The magnetorheological polishing module includes a magnetorheological mounting frame 202, a polishing wheel 203, an electromagnet 204, a nozzle 205, a liquid pump 206, a current intensity controller 218, a position adjustment mechanism, and a polishing wheel drive mechanism. The magnetorheological mounting frame 202 is installed at the tool end of the industrial robot 201. The polishing wheel drive mechanism is installed on the magnetorheological mounting frame 202 and is used to drive the polishing wheel 203 to rotate to process the element to be polished 101 or the test polishing element 102. The nozzle 205 is installed on the magnetorheological mounting frame 202 and is used to spray magnetorheological fluid onto the polishing wheel 203. The electromagnet 204 is installed on the mounting plate 219, near the working point of the polishing wheel 203 (the working point of the polishing wheel 203 is the closest point to the surface of the element to be polished 101 along the normal direction of the surface of the element to be polished 101), and the mounting plate 219 is installed on the magnetorheological mounting frame 202 and is used to change the stiffness of the magnetorheological fluid. The current intensity controller 218 is arranged on one side of the polishing platform 1 and is used to control the energizing current of the electromagnet 204 and adjust the magnetic field intensity of the electromagnet 204. The liquid pump 206 is installed on the industrial robot 201 or arranged on the support frame 220 on one side of the industrial robot 201. The liquid pump 206 is connected to the nozzle 205 through a pipeline and is used to pump magnetorheological fluid into the nozzle 205. The liquid pump 206 selects the DFLD vertical multistage pump of Shanghai Dongfang Pump Industry Co., Ltd. The position adjustment mechanism is installed on the magnetorheological mounting frame 202 and is used to adjust the position of the polishing wheel 203. The operating parameters of the magnetorheological polishing module include the magnetic field intensity of the electromagnet 204 and the position of the polishing wheel 203. A detection circuit, which is used to output a constant voltage, and when the magnetorheological polishing module contacts the surface of the test polishing element 102, form a first closed loop and detect the first instantaneous current in the first closed loop in real time, or when the magnetorheological polishing module contacts the surface of the element to be polished 101, form a second closed loop and detect the second instantaneous current in the second closed loop in real time. A computer 3, which is used to calculate the corresponding relationship between the operating parameters of the magnetorheological polishing module and the ideal instantaneous current according to the polishing data. The polishing data includes the first instantaneous current data detected by the detection circuit under different operating parameters of the magnetorheological polishing module. And the computer 3 is used to adjust the current operating parameters when it is determined that the error between the second instantaneous current detected by the detection circuit and the ideal instantaneous current corresponding to the current operating parameters exceeds the preset error range, so that the error between the second instantaneous current detected by the detection circuit after the operating parameters are adjusted and the corresponding ideal instantaneous current is within the preset error range.

[0020] In this embodiment, the polishing platform 1 refers to the working platform for experiments, on which there are placed a test polishing element 102, a component to be polished 101, and other polishing components. For example, the magnetorheological fluid required for polishing, the supporting tooling for the component to be polished, etc. Among them, the test polishing element 102 is a reference piece required for calculating the ideal instantaneous current corresponding to the operating parameters, and the component to be polished 101 is the component that needs to be processed by magnetorheological polishing.

[0021] In this embodiment, the industrial robot 201 can adopt a six-degree-of-freedom robotic arm or other robots with pose adjustment functions.

[0022] The position adjustment mechanism includes a support fixing frame 207, a ball screw stepping motor 208, and a connecting plate 209. The ball screw stepping motor 208 is vertically installed on the magnetorheological mounting frame 202 through the support fixing frame 207. The nut 217 of the ball screw stepping motor 208 is fixedly connected to the connecting plate 209, and the polishing wheel 203 is connected to the connecting plate 209. The polishing wheel 203 is driven by the ball screw stepping motor 208 to move for position adjustment.

[0023] The polishing wheel driving mechanism includes a driving motor 210, a driving wheel 211, a driven wheel 212, and a synchronous belt 213. The driving motor 210 is installed on the connecting plate 209. A bearing seat is installed on the connecting plate 209, and a bearing is installed in the bearing seat. The bearing is connected to the polishing wheel 203. The driven wheel 212 is sleeved on the bearing, the driving wheel 211 is sleeved on the output end of the driving motor 210, and the synchronous belt 213 is tensioned between the driven wheel 212 and the driving wheel 211. The polishing wheel 203 is driven by the driving motor 210 to rotate. Reference can be made to the Chinese patent with the publication date of July 12, 2024 and the publication number of CN118322074A. By driving the polishing wheel 203 to rotate at a high speed by the driving motor 210, the magnetorheological fluid is brought into the magnetic field action area, and the magnetorheological fluid flow forms a magnetorheological ribbon under the action of the magnetic field.

[0024] In the embodiment of the present invention, to ensure that the polishing wheel 203 and the electromagnet 204 can move stably along the lead screw 214 of the ball screw stepping motor 208, it is preferably to install a guide rail 215 on each side of the lead screw 214 on the support fixing frame 207, and the two guide rails 215 are parallel to the lead screw 214. A slider 216 is slidably connected to the two guide rails 215. At this time, the connecting plate 209 is fixedly connected to the nut 217 and the two sliders 216 at the same time. During polishing, the computer 3 sends a control signal to the ball screw stepping motor 208, and the ball screw stepping motor 208 drives the connecting plate 209 to move linearly under the sliding cooperation of the guide rail 215 and the slider 216.

[0025] It should be noted that there is a strong magnetic phenomenon in the working area where the magnetorheological polishing module is located. The connection of various circuits needs to avoid the working area to prevent the wires from being adsorbed onto the magnetorheological polishing module and affecting the normal operation. Preferably, the fixed voltage should not exceed the human safety voltage, and the instantaneous current value measured using the contact resistance should not exceed the human safety current.

[0026] In this embodiment, taking the test polishing element 102 as an example, the polishing principle is described as follows: When the polishing wheel 203 performs polishing, the magnetorheological fluid is affected by the magnetic field change and changes from a liquid state to a quasi-solid state, forming a Bingham fluid. By rotating the polishing wheel 203, the Bingham fluid applies a shear force to the outer surface of the test polishing element 102, achieving the polishing of the test polishing element 102. Different operating parameters of the magnetorheological polishing module (including different positions of the polishing wheel 203 and different magnetic field intensities of the electromagnet 204) correspond to different shear forces and different polishing effects.

[0027] Through the magnetorheological polishing module, flexible polishing of various components can be achieved, especially for optical elements with high-precision requirements on the outer surface.

[0028] In this embodiment, the detection circuit is a detection circuit built based on the principle of resistance change. There are pressures between the magnetorheological polishing module and the test polishing element 102, and between the magnetorheological polishing module and the element to be polished 101. Different polishing gaps correspond to different pressures, and the change in pressure will cause a change in the contact resistance, so the current passing through the contact resistance will change. Taking the test polishing element 102 as an example, the same applies to the element to be polished 101, as follows: The detection circuit applies a fixed voltage between the magnetorheological polishing module and the test polishing element 102. Using the relationship between the contact resistance and the pressure, the resistance value caused by the pressure change is calculated. Then, through the relationship between the fixed voltage, the contact resistance, and the instantaneous current, the instantaneous current value is calculated using Ohm's law. The instantaneous current value in the first closed loop is the first instantaneous current. The relationship between the pressure and the contact resistance can be expressed by the following formula: ; Where, is the resistance value of the contact resistance, is the material coefficient, is the pressure when the magnetorheological polishing module contacts the test polishing element 102, is the coefficient corresponding to the contact form (including point contact, surface contact, line contact, etc.). In this embodiment, is surface contact, so .

[0029] The detection circuit can be implemented by the above-mentioned current intensity controller 218. The current intensity controller 218 can adopt the DA conversion module of the Smart200 series of Siemens Corporation, which can not only sense the first instantaneous current between the test polishing element 102 and the polishing wheel 203, but also control the magnetic field intensity of the electromagnet 204.

[0030] In this embodiment, the computer 3 is used to calculate the corresponding relationship between different operating parameters of the magnetorheological polishing module and the ideal instantaneous current according to the polishing data collected by the detection circuit under different operating parameters of the magnetorheological polishing module. The polishing data includes the first instantaneous current data in the first closed loop detected by the detection circuit under different operating parameters.

[0031] Different operating parameters can be preset. Different operating parameters should cover the maximum polishing gap and the minimum polishing gap that the driving unit can move the magnetorheological polishing module to. The polishing data can be collected multiple times, and finally, the error between multiple sets of polishing data can be reduced by numerical calculation methods such as taking the mean or variance, and then the relationship between the ideal instantaneous current and the operating parameters can be calculated according to the polishing data.

[0032] In this embodiment, the computer 3 calculates the corresponding relationship between different operating parameters and the ideal instantaneous current by calculating the correlation between the first instantaneous current data in the first closed loop and its corresponding operating parameters. With this as a reference, when polishing the element 101 to be polished, by comparing whether the difference between the second instantaneous current corresponding to the operating parameters in the second closed loop of the element 101 to be polished and the ideal instantaneous current under this operating parameter is within the preset error range. If not, the operating parameters are adjusted so that the second instantaneous current is the same as or within the same preset error range as the corresponding ideal instantaneous current. This method can achieve the effect of real-time adjustment of the operating parameters during the polishing process based on the corresponding relationship between the operating parameters and the instantaneous current, thereby obtaining the function of automatically compensating the operating parameters.

[0033] When polishing the test polishing element 102 using the magnetorheological polishing module, different operating parameters and their corresponding first instantaneous currents are collected. Then, based on the collected operating parameters and the first instantaneous currents, the corresponding relationship between the operating parameters and the ideal instantaneous current is calculated. Subsequently, the second instantaneous current is judged according to this relationship, and whether to adjust the operating parameters is determined based on the judgment result, so as to realize the real-time adjustment of the operating parameters, making the flow rate fluctuation of the magnetorheological fluid at each machining trajectory point meet the requirements of high-precision polishing and ensuring the constancy of the removal function. This process does not require calibration steps for parameters such as gravity compensation and is not affected by factors such as the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy of the equipment itself, the running speed, the posture, the inertia, and other factors. The accuracy of the measured data is only limited by the current measurement accuracy of the second instantaneous current between the magnetorheological polishing module and the element to be polished. The measurement result is more accurate, and there is no need to add equipment such as high-precision force sensors, reducing the equipment cost.

[0034] In a second aspect, the present embodiment further provides a magnetorheological processing control method based on magnetic field strength adjustment, which is implemented using the above-mentioned magnetorheological processing control device based on instantaneous current sensing. The magnetorheological processing control method includes the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different electromagnetic field strengths of the electromagnet to process the test polishing element, and the detection circuit detects the first instantaneous current in the first closed loop in real time to obtain the corresponding relationship between the liquid pump height and the first instantaneous current , represents the first instantaneous current, represents the electromagnetic field strength of the electromagnet, represents the conversion relationship between the electromagnetic field strength of the electromagnet and the first instantaneous current. Multiple groups of first instantaneous currents and the corresponding electromagnetic field strengths of the electromagnet are mapped and stored to obtain polishing data. The computer calculates the corresponding relationship between the electromagnetic field strength of the electromagnet and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current electromagnetic field strength of the electromagnet exceeds the preset error range, the electromagnetic field strength of the electromagnet is adjusted through the current intensity controller so that the error between the second instantaneous current detected by the detection circuit after the adjustment of the electromagnetic field strength of the electromagnet and the corresponding ideal instantaneous current is within the preset error range.

[0035] In this embodiment, it is necessary to first obtain the correspondence between the ideal instantaneous current and the electromagnetic field strength of the electromagnet. The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The part where the polishing wheel contacts the test polishing element is recorded as the first machining trajectory point. During the process of measuring the same set of polishing data, the first machining trajectory point remains unchanged. Optionally, when measuring multiple sets of polishing data, different first machining trajectory points can be selected on the test polishing element to facilitate improving the accuracy of the correspondence between the ideal instantaneous current and the electromagnetic field strength of the electromagnet.

[0036] During the process of the polishing wheel machining the test polishing element, the computer controls the drive motor to set different electromagnetic field strengths of the electromagnet, collects the first instantaneous current in the first closed loop corresponding to different electromagnetic field strengths, maps and stores multiple sets of the first instantaneous current and the corresponding electromagnetic field strength to obtain polishing data, and the computer calculates the correspondence between the electromagnetic field strength and the ideal instantaneous current according to the polishing data.

[0037] After obtaining the correspondence between the ideal instantaneous current and the electromagnetic field strength of the electromagnet, when machining the element to be polished, the electromagnetic field strength can be adjusted according to this correspondence so that the second instantaneous current corresponding to the current electromagnetic field strength and the ideal instantaneous current are within the same preset error range.

[0038] In some embodiments, the correspondence between the electromagnetic field strength of the electromagnet and the ideal instantaneous current is a functional curve relationship, which is characterized by the correspondence between the electromagnetic field strength of the electromagnet and the first instantaneous current. The correspondence between the electromagnetic field strength of the electromagnet and the first instantaneous current is obtained by fitting based on multiple discrete values of the electromagnetic field strength of the electromagnet and the first instantaneous current.

[0039] In this embodiment, multiple electromagnetic field strengths of the electromagnet correspond to multiple first instantaneous currents, and both the electromagnetic field strength of the electromagnet and the first instantaneous current are discrete values. Therefore, it is necessary to fit the discrete values.

[0040] Fitting process: Import the discrete data into the Matlab software, and complete the data fitting with the help of the polyfit fitting instruction of the Matlab software to solve the correspondence between the electromagnetic field strength of the electromagnet and the current parameters ; The Polyfit fitting instruction is a basic general instruction of the matlab software. Finally, the correspondence between the electromagnetic field strength of the electromagnet and the first instantaneous current is: .

[0041] In this way, the corresponding relationship between the ideal instantaneous current and the electromagnetic field strength of the electromagnet can be seen more intuitively. Based on this, different components to be polished under the same polishing conditions can be processed, and the automatic compensation effect of the electromagnetic field strength of the electromagnet can be achieved.

[0042] In some embodiments, the sampling period for the detection circuit to collect the second instantaneous current is denoted as , and the shortest time required to adjust the electromagnetic field strength of the electromagnet to the maximum adjustment amount is denoted as , , and the shortest switching time between two adjacent processing trajectory points on the component to be polished is denoted as , ; where is the fastest adjustment speed of the electromagnetic field strength of the electromagnet, is the highest moving speed of the industrial robot, and represents the distance between two adjacent processing trajectory points on the component to be polished.

[0043] The method for adjusting the sampling frequency of the detection circuit includes: Judging whether the relationship between , , satisfies the formula: ; If not, adjust the sampling frequency of the detection circuit for collecting the second instantaneous current until the formula is satisfied, and the sampling frequency is .

[0044] In this embodiment, the above formula gives the corresponding relationship among three time elements, that is: within a single sampling period, the industrial robot can adjust the magnetorheological polishing module so that it moves to the electromagnetic field strength of the electromagnet corresponding to the ideal instantaneous current, and then performs the next sampling, avoiding too long a sampling period resulting in too slow a sampling frequency, making the sampling frequency not match the adjustment speed of the electromagnetic field strength of the electromagnet, and the adjustment is not timely, resulting in the inability to know the current state of the second instantaneous current and affecting the automatic compensation function of the electromagnetic field strength of the electromagnet.

[0045] In some embodiments, if the current electromagnetic field strength is adjusted to the error between the second instantaneous current and the ideal instantaneous current corresponding to the current electromagnetic field strength is equal to or greater than the upper threshold of the preset error range, the adjustment amplitude corresponding to the current electromagnetic field strength is , and the value of the second instantaneous current corresponding to the current electromagnetic field strength is , represents the ideal instantaneous current value, Indicates the adjustment amplitude of the second instantaneous current; If the current electromagnetic magnetic field strength Adjust to the second instantaneous current and the current electromagnetic magnetic field strength When the error of the corresponding ideal instantaneous current is equal to or greater than the lower limit threshold of the preset error range, the current electromagnetic magnetic field strength The corresponding adjustment range is , the current electromagnetic magnetic field strength The corresponding second instantaneous current The value of .

[0046] The current intensity controller controls the electromagnetic magnetic field intensity of the current processing trajectory point Make adjustments, including: If the second instantaneous current Does not exceed the allowable variation range When the motor of the liquid pump is not controlled, the electromagnetic magnetic field strength of the current processing trajectory point is maintained. constant; If the second instantaneous current Exceeding the allowable variation range and|A i |<|A0±ΔA max |, then the electromagnetic magnetic field strength of the current processing trajectory point is calculated according to the following formula To make adjustments: ; in, represents the ideal instantaneous current value, Indicates the adjustment amplitude of the second instantaneous current; If the second instantaneous current Exceeding the allowable variation range And |A i |>|A0±ΔA max |, then the electromagnetic magnetic field strength of the current processing trajectory point is calculated according to the following formula To make adjustments: ; in, Indicates the set initial magnetic field strength of the electromagnet.

[0047] It should be noted that the electromagnetic magnetic field strength at the current processing trajectory point and the current electromagnetic magnetic field strength have the same meaning.

[0048] The intensity of the electromagnetic magnetic field at the current processing trajectory point After adjustment, the electromagnetic field intensity of the next machining trajectory point The corresponding second instantaneous current Returns to the allowable change range to meet the requirements of the polishing gap change for magnetorheological high-precision machining.

[0049] When the above technical solution uses the magnetorheological polishing module to process the test polishing element, different electromagnetic field intensities of the electromagnet and the corresponding first instantaneous current are collected. Then, the corresponding relationship between the electromagnetic field intensity of the electromagnet and the ideal instantaneous current is calculated through the collected electromagnetic field intensity of the electromagnet and the first instantaneous current. After that, the second instantaneous current is judged through this relationship, and whether to adjust the electromagnetic field intensity of the electromagnet is determined according to the judgment result, so as to realize the real-time adjustment and compensation of the electromagnetic field intensity of the electromagnet, make the flow fluctuation of the magnetorheological fluid at each machining trajectory point meet the requirements of high-precision polishing, and ensure the constancy of the removal function. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy, running speed, posture, inertia and other factors of the equipment itself. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current between the magnetorheological polishing module and the element to be polished. The measurement result is more accurate, and there is no need to add equipment such as high-precision force sensors, reducing the equipment cost.

[0050] In a third aspect, the present embodiment further provides a magnetorheological processing control method based on the simultaneous adjustment of the polishing wheel position and the magnetic field intensity, which is realized by using the above-mentioned magnetorheological processing control device based on instantaneous current sensing. The magnetorheological processing control method is characterized in that it includes the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different polishing wheel positions to process the test polishing element, and the detection circuit detects the first instantaneous current in the first closed loop in real time to obtain the corresponding relationship between the polishing wheel position and the first instantaneous current , represents the first instantaneous current, represents the polishing wheel position, represents the conversion relationship between the polishing wheel position and the first instantaneous current. Multiple groups of first instantaneous currents and the corresponding polishing wheel positions are mapped and stored to obtain polishing data. The computer calculates the corresponding relationship between the polishing wheel position and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current polishing wheel position exceeds the preset error range, the position of the polishing wheel is adjusted by the ball screw stepping motor and the magnetic field strength of the electromagnet is adjusted by the current intensity controller, so that the error between the second instantaneous current detected by the detection circuit after the position of the polishing wheel and the magnetic field strength of the electromagnet are adjusted and the corresponding ideal instantaneous current is within the preset error range.

[0051] In this embodiment, it is necessary to first obtain the correspondence between the ideal instantaneous current and the polishing wheel position. The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The part where the polishing wheel contacts the test polishing element is recorded as the first machining trajectory point. During the process of measuring the same set of polishing data, the first machining trajectory point remains unchanged. Optionally, when measuring multiple sets of polishing data, different first machining trajectory points can be selected on the test polishing element to facilitate improving the accuracy of the correspondence between the ideal instantaneous current and the polishing wheel position.

[0052] During the process of the polishing wheel machining the test polishing element, the computer controls the drive motor to set different polishing wheel positions, collects the first instantaneous current in the first closed loop corresponding to different polishing wheel positions, maps and stores multiple sets of the first instantaneous current and the corresponding polishing wheel positions to obtain polishing data, and the computer calculates the correspondence between the polishing wheel position and the ideal instantaneous current according to the polishing data.

[0053] After obtaining the correspondence between the ideal instantaneous current and the polishing wheel position, when machining the element to be polished, the position of the polishing wheel and the magnetic field strength of the electromagnet can be adjusted simultaneously according to this correspondence, so that the second instantaneous current corresponding to the current polishing wheel position and the ideal instantaneous current are within the same preset error range.

[0054] Since when the position of the polishing wheel changes, the relative distance between the polishing wheel and the electromagnet changes, resulting in a change in the magnetic field strength acting on the magnetorheological fluid at the polishing wheel, it is necessary to adjust the magnetic field strength of the electromagnet while adjusting the position of the polishing wheel to achieve compensation for the magnetic field strength and maintain the stability of the removal function.

[0055] In some embodiments, the correspondence between the polishing wheel position and the ideal instantaneous current is a functional curve relationship, which is characterized by the correspondence between the polishing wheel position and the first instantaneous current. The correspondence between the polishing wheel position and the first instantaneous current is obtained by fitting according to the discrete values of multiple polishing wheel positions and the first instantaneous current.

[0056] In this embodiment, multiple polishing wheel positions correspond to multiple first instantaneous currents. Both the polishing wheel positions and the first instantaneous currents are discrete values. Therefore, it is necessary to fit the discrete values.

[0057] Fitting process: Import the discrete data into Matlab software, and use the polyfit fitting instruction of Matlab software to complete data fitting and solve the corresponding relationship between the polishing wheel position and the current parameter. ; The Polyfit fitting instruction is a basic general instruction in Matlab software. Finally, the corresponding relationship between the polishing wheel position LM and the first instantaneous current A is obtained as: .

[0058] In this way, the corresponding relationship between the ideal instantaneous current and the polishing wheel position can be more intuitively seen. Based on this, the component to be polished under the same polishing conditions can be processed, and the automatic compensation effect of the polishing wheel position and the electromagnetic field strength of the electromagnet can be achieved.

[0059] In some embodiments, the sampling period for the detection circuit to collect the second instantaneous current is denoted as , the shortest time required to adjust the polishing wheel position to the maximum adjustment amount is denoted as , , the shortest time required to adjust the electromagnetic field strength of the electromagnet to the maximum adjustment amount is denoted as , , the shortest time for switching between two adjacent processing trajectory points on the component to be polished is denoted as , ; where is the fastest adjustment speed of the polishing wheel position change, is the fastest adjustment speed of the electromagnetic field strength change of the electromagnet, is the highest moving speed of the industrial robot, represents the distance between two adjacent processing trajectory points on the component to be polished.

[0060] The adjustment method for the sampling frequency of the detection circuit includes: Judge , , , whether the relationship between them satisfies the formula: ; If not, adjust the sampling frequency of the detection circuit to collect the second instantaneous current until the formula is satisfied, and the sampling frequency is .

[0061] In this embodiment, the above formula gives the correspondence relationship among four time elements, that is: within a single sampling period, the industrial robot can adjust the magnetorheological polishing module so that it moves to the polishing wheel position corresponding to the ideal instantaneous current and the electromagnetic field strength of the electromagnet, and then conducts the next sampling, avoiding the sampling frequency being too slow due to too long sampling period, making the sampling frequency not match the adjustment speed of the polishing wheel position and the electromagnetic field strength of the electromagnet, and the adjustment is not timely, resulting in the inability to know the current state of the second instantaneous current and affecting the automatic compensation function of the polishing wheel position and the electromagnetic field strength of the electromagnet.

[0062] In some embodiments, if the current polishing wheel position is adjusted to the second instantaneous current and the error between the ideal instantaneous current corresponding to the current polishing wheel position is equal to or greater than the upper threshold value of the preset error range, the adjustment amplitude corresponding to the current polishing wheel position is , and the value of the second instantaneous current corresponding to the current polishing wheel position is , represents the ideal instantaneous current value, represents the adjustment amplitude of the second instantaneous current; If the current polishing wheel position is adjusted to the second instantaneous current and the error between the ideal instantaneous current corresponding to the current polishing wheel position is equal to or greater than the lower threshold value of the preset error range, the adjustment amplitude corresponding to the current polishing wheel position is , and the value of the second instantaneous current corresponding to the current polishing wheel position is .

[0063] Adjusting the polishing wheel position of the current machining trajectory point through the ball screw stepping motor and adjusting the electromagnetic field strength of the electromagnet at the current machining trajectory point through the current intensity controller includes: If the second instantaneous current does not exceed the allowable change range , do not control the ball screw stepping motor and the current intensity controller, and keep the polishing wheel position and the electromagnetic field strength of the current machining trajectory point unchanged; If the second instantaneous current exceeds the allowable change range and When it is, the polishing wheel position of the current machining trajectory point is adjusted according to the following formula and the electromagnetic field strength of the electromagnet are adjusted as follows: ; ; wherein, represents the ideal instantaneous current value, represents the adjustment amplitude of the second instantaneous current, represents the change amount of the polishing wheel position, represents the distance between the electromagnet and the working point of the polishing wheel, represents the magnetic moment, is the proportionality coefficient; If the second instantaneous current exceeds the allowable change range and When it is, the polishing wheel position of the current machining trajectory point is adjusted according to the following formula and the electromagnetic field strength of the electromagnet are adjusted as follows: ; ; wherein, represents the set initial position of the polishing wheel, represents the set initial magnetic field strength of the electromagnet.

[0064] It should be noted that the polishing wheel position of the current machining trajectory point has the same meaning as the current polishing wheel position.

[0065] After adjusting the polishing wheel position of the current machining trajectory point and the electromagnetic field strength of the electromagnet , the polishing wheel position of the next machining trajectory point and the electromagnetic field strength of the electromagnet The corresponding second instantaneous current returns to the allowable change range to meet the requirements of the polishing gap change for magnetorheological high-precision machining.

[0066] When the above technical solution uses the magnetorheological polishing module to process the test polishing element, different polishing wheel positions and the corresponding first instantaneous current are collected, and then the corresponding relationship between the polishing wheel position and the ideal instantaneous current is calculated through the collected polishing wheel position and the first instantaneous current. After that, the second instantaneous current is determined through this relationship, and whether to adjust the polishing wheel position and the electromagnetic field strength of the electromagnet is decided according to the determination result, so as to realize the real-time adjustment and compensation of the polishing wheel position and the electromagnetic field strength of the electromagnet, make the flow rate fluctuation of the magnetorheological fluid at each processing trajectory point meet the requirements of high-precision polishing, and ensure the constancy of the removal function. This process does not require calibration steps for parameters such as gravity compensation, and is not affected by factors such as the weight of the magnetorheological processing module of the robot magnetorheological processing equipment, the running accuracy, running speed, posture, inertia and other factors of the equipment itself. The accuracy of the measurement data is only limited by the current measurement accuracy of the second instantaneous current between the magnetorheological polishing module and the element to be polished. The measurement result is more accurate, and there is no need to add equipment such as high-precision force sensors, reducing the equipment cost.

[0067] It should be understood that various forms of the processes shown above can be used, with steps reordered, added or deleted. For example, the steps described in the disclosure of the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and no limitation is made herein.

[0068] The above specific embodiments do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A magnetorheological machining control device based on instantaneous current sensing, characterized in that, Comprising: A polishing platform, on which an element to be polished and a test polishing element are arranged; A polishing assembly, including an industrial robot and a magnetorheological polishing module. The industrial robot is used to drive the magnetorheological polishing module to move to the position where the test polishing element is located or the position where the element to be polished is located. The magnetorheological polishing module is used to process the element to be polished or the test polishing element. The magnetorheological polishing module includes a magnetorheological mounting frame, a polishing wheel, a nozzle, an electromagnet, a liquid pump, a position adjustment mechanism and a current intensity controller. The magnetorheological mounting frame is mounted on the tool end of the industrial robot. The current intensity controller, the position adjustment mechanism, the nozzle and the electromagnet are respectively mounted on the magnetorheological mounting frame. The liquid pump is arranged on the industrial robot or on one side of the industrial robot. The liquid pump is used to pump magnetorheological fluid into the nozzle. The nozzle is used to spray magnetorheological fluid onto the polishing wheel. The electromagnet is used to change the stiffness of the magnetorheological fluid. The position adjustment mechanism is used to adjust the position of the polishing wheel. The polishing wheel is used to process the test polishing element or the element to be polished. The current intensity controller is used to control the energizing current of the electromagnet and adjust the magnetic field intensity of the electromagnet. The operating parameters of the magnetorheological polishing module include the magnetic field intensity of the electromagnet and the position of the polishing wheel; A detection circuit, which is used to output a constant voltage, and when the magnetorheological polishing module contacts the surface of the test polishing element, form a first closed loop and detect the first instantaneous current in the first closed loop in real time, or when the magnetorheological polishing module contacts the surface of the element to be polished, form a second closed loop and detect the second instantaneous current in the second closed loop in real time; A computer, which is used to calculate the corresponding relationship between the operating parameters of the magnetorheological polishing module and the ideal instantaneous current according to the polishing data. The polishing data includes the first instantaneous current data detected by the detection circuit under different operating parameters of the magnetorheological polishing module; And the computer is used to adjust the current operating parameters when it is determined that the error between the second instantaneous current detected by the detection circuit and the ideal instantaneous current corresponding to the current operating parameters exceeds the preset error range, so that the error between the second instantaneous current detected by the detection circuit after the operating parameters are adjusted and the corresponding ideal instantaneous current is within the preset error range.

2. The magnetorheological machining control device based on instantaneous current sensing according to claim 1, wherein The position adjustment mechanism includes a support fixing frame, a ball screw stepping motor and a connecting plate. The ball screw stepping motor is mounted on the magnetorheological mounting frame through the support fixing frame. The nut of the ball screw stepping motor is fixedly connected to the connecting plate. The polishing wheel and the magnet are both mounted on the connecting plate.

3. The magnetorheological machining control device based on instantaneous current sensing according to claim 1, wherein The magnetorheological polishing module further includes a polishing wheel driving mechanism. The polishing wheel driving mechanism includes a driving motor, a driving wheel, a driven wheel and a synchronous belt. The driving motor is mounted on the connecting plate. A bearing seat is mounted on the connecting plate. A bearing is mounted in the bearing seat. The bearing is connected to the polishing wheel. The driven wheel is sleeved on the bearing. The driving wheel is sleeved on the output end of the driving motor. The synchronous belt is tensioned between the driven wheel and the driving wheel.

4. A magnetic rheological processing control method based on magnetic field strength adjustment, which is realized by using the magnetic rheological processing control device based on instantaneous current sensing described in claim 1, and is characterized in that, The magnetorheological processing regulation method includes the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different electromagnetic field intensities of the electromagnet to process the test polishing element, and the detection circuit detects the first instantaneous current in the first closed loop in real time to obtain the corresponding relationship between the height of the liquid pump and the first instantaneous current , represents the first instantaneous current, represents the electromagnetic field intensity of the electromagnet, represents the conversion relationship between the electromagnetic field intensity of the electromagnet and the first instantaneous current. Multiple groups of first instantaneous currents and the corresponding electromagnetic field intensities of the electromagnet are mapped and stored to obtain polishing data. The computer calculates the corresponding relationship between the electromagnetic field intensity of the electromagnet and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current electromagnet magnetic field strength exceeds the preset error range, the current intensity controller is used to adjust the electromagnet magnetic field strength so that the error between the second instantaneous current detected by the detection circuit after the adjustment of the electromagnet magnetic field strength and the corresponding ideal instantaneous current is within the preset error range.

5. The magnetic rheological machining control method based on magnetic field strength adjustment according to claim 4, characterized in that Denote the sampling period for the detection circuit to collect the second instantaneous current as , and denote the shortest time required to adjust the electromagnetic field strength of the electromagnet to the maximum adjustment amount as . , , and denote the shortest switching time between two adjacent machining trajectory points on the component to be polished as . ; where is the fastest adjustment speed of the change in the electromagnetic field strength of the electromagnet,[[]] is the highest moving speed of the industrial robot,[[]] represents the distance between two adjacent machining trajectory points on the component to be polished; The method for adjusting the sampling frequency of the detection circuit includes: Determine , , Whether the relationship between them satisfies the formula: ； If not satisfied, adjust the sampling frequency of the detection circuit for collecting the second instantaneous current until the formula is satisfied, and the sampling frequency is .

6. The magnetic rheological machining control method based on magnetic field strength adjustment according to claim 5, wherein Adjust the magnetic field strength of the electromagnet at the current machining trajectory point through the current intensity controller including: If the second instantaneous current does not exceed the allowable change range the motor of the liquid pump is not controlled, and the magnetic field strength of the electromagnet at the current machining trajectory point is maintained unchanged; If the second instantaneous current exceeds the allowable change range and |A i | < |A0 ± ΔA max |, then the electromagnetic field strength of the current machining trajectory point is adjusted according to the following formula as follows: ； Among them, represents the ideal instantaneous current value, represents the adjustment amplitude of the second instantaneous current; If the second instantaneous current exceeds the allowable change range and |A i | > |A0 ± ΔA max |, then the electromagnetic field strength of the current machining trajectory point is adjusted according to the following formula as follows: ； Among them, represents the set initial magnetic field strength of the electromagnet.

7. A magnetorheological machining control method based on simultaneous adjustment of the position of the polishing wheel and the magnetic field strength, which is realized by using the magnetorheological machining control device based on instantaneous current sensing described in claim 2, and is characterized in that, This magnetorheological processing control method includes the following steps: The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the test polishing element. The computer sets different positions of the polishing wheel to process the test polishing element, and the detection circuit detects the first instantaneous current in the first closed loop in real time to obtain the corresponding relationship between the polishing wheel position and the first instantaneous current. , represents the first instantaneous current, represents the polishing wheel position, represents the conversion relationship between the polishing wheel position and the first instantaneous current. Multiple groups of the first instantaneous currents and the corresponding polishing wheel positions are mapped and stored to obtain the polishing data. The computer calculates the corresponding relationship between the polishing wheel position and the ideal instantaneous current according to the polishing data; The industrial robot drives the magnetorheological polishing module to move until it contacts the surface of the element to be polished. The detection circuit detects the second instantaneous current in the second closed loop in real time. When the computer determines that the error between the second instantaneous current and the ideal instantaneous current corresponding to the current polishing wheel position exceeds the preset error range, the polishing wheel position is adjusted by the ball screw stepping motor and the electromagnet magnetic field strength is adjusted by the current intensity controller so that the error between the second instantaneous current detected by the detection circuit after the adjustment of the polishing wheel position and the electromagnet magnetic field strength and the corresponding ideal instantaneous current is within the preset error range.

8. The magnetorheological machining control method based on simultaneous adjustment of the position of the polishing wheel and the magnetic field strength according to claim 7, characterized in that Denote the sampling period for the detection circuit to collect the second instantaneous current as , and denote the shortest time required to adjust the position of the polishing wheel to the maximum adjustment amount as ; denote the shortest time required to adjust the magnetic field intensity of the electromagnet to the maximum adjustment amount as , , and denote the shortest switching time between two adjacent machining trajectory points on the component to be polished as ; where , , ; among them, ; where is the fastest adjustment speed of the position change of the polishing wheel, is the fastest adjustment speed of the magnetic field intensity change of the electromagnet, is the highest moving speed of the industrial robot, represents the distance between two adjacent machining trajectory points on the component to be polished; The method for adjusting the sampling frequency of the detection circuit includes: Determine , , , Whether the relationship between them satisfies the formula: ； If not satisfied, adjust the sampling frequency of the detection circuit for collecting the second instantaneous current until the formula is satisfied, and the sampling frequency is .

9. The magnetorheological machining control method based on simultaneous adjustment of the position of the polishing wheel and the magnetic field strength according to claim 8, wherein Adjust the position of the polishing wheel at the current machining trajectory point through a ball screw stepper motor Adjust the magnetic field strength of the electromagnet at the current machining trajectory point through a current intensity controller The adjustment includes: If the second instantaneous current does not exceed the allowable change range the ball screw stepper motor and the current intensity controller are not controlled, and the position of the polishing wheel at the current machining trajectory point and the magnetic field intensity of the electromagnet remain unchanged; If the second instantaneous current exceeds the allowable change range and at this time, then the polishing wheel position of the current machining trajectory point and the electromagnetic field strength of the electromagnet are adjusted according to the following formula: ； ； Among them, represents the ideal instantaneous current value, represents the adjustment amplitude of the second instantaneous current, represents the change amount of the polishing wheel position, represents the distance between the electromagnet and the working point of the polishing wheel, represents the magnetic moment, is the proportionality coefficient; If the second instantaneous current exceeds the allowable change range and at this time, then the polishing wheel position of the current machining trajectory point and the electromagnetic field strength of the electromagnet are adjusted according to the following formula: ； ； Among them, represents the set initial position of the polishing wheel, represents the set initial magnetic field intensity of the electromagnet.

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