Polishing method and system

Abstract

The invention relates to the technical field of polishing processing of optical elements and semiconductor materials, and particularly provides a polishing method and system.The method comprises the steps that a to-be-polished element is placed at a preset position, the to-be-polished element is polished according to a polishing path, and the polishing path is determined according to surface structure parameters of the to-be-polished element; in the polishing process, the position information of the polishing equipment and the acting force of the polishing equipment on the to-be-polished element are obtained, and the position information is used for adjusting the acting force; and feedback control is conducted on the polishing equipment according to the acting force and the position information till the polishing equipment completes the polishing path. The problems that in the prior art, the polishing precision is low, and the polishing quality is unstable are solved.

Description

Technical Field

[0001] The invention relates to the technical field of polishing processing of optical elements and semiconductor materials, and in particular to a polishing method and system. Background Art

[0002] As optical components and semiconductor materials develop towards high precision, higher requirements are placed on polishing processing technology.

[0003] Polishing methods are primarily divided into mechanical polishing and plasma polishing. Mechanical polishing relies on traditional equipment and processes, making it difficult to meet high-precision requirements and prone to scratches and subsurface damage. While plasma polishing offers higher polishing accuracy than mechanical polishing, it has stricter requirements for material and surface properties, and the technology is still immature, resulting in inconsistent polishing quality.

[0004] Currently, no effective solution has been proposed to address the problems of low polishing precision and unstable polishing quality in related technologies. Summary of the Invention

[0005] The present invention provides a polishing method and system that at least solve the problems of low polishing precision and unstable polishing quality in related technologies.

[0006] A polishing method provided by an embodiment of the present invention includes: placing an element to be polished at a preset position, and polishing the element to be polished according to a polishing path, wherein the polishing path is determined based on surface structural parameters of the element to be polished; during the polishing process, obtaining position information of a polishing device and the force exerted by the polishing device on the element to be polished, wherein the position information is used to adjust the force; and performing feedback control on the polishing device based on the force and position information until the polishing device completes the polishing path.

[0007] The polishing method provided by the embodiment of the present invention performs feedback control on the polishing equipment according to the applied force and position information until the polishing equipment completes the polishing path, including: determining the error force according to the applied force and the expected force, wherein the expected force is determined according to the process requirements of the element to be polished; determining the force control signal based on the error force, the proportional gain, and the differential gain, wherein the proportional gain and the differential gain are adjusted by adaptive parameters, and the adaptive parameters are related to the polishing environment; determining the force adjustment signal according to the position information and the expected position, wherein the position information is the actual position of the end effector of the robotic arm of the polishing equipment, and the expected position is determined according to the polishing path; controlling the force applied by the robotic arm to the element to be polished based on the force control signal, and adjusting the applied force through the force adjustment signal until the polishing equipment completes the polishing path.

[0008] The polishing method provided by the embodiment of the present invention places the element to be polished at a preset position, and before polishing the element to be polished according to the polishing path, the method further includes: obtaining the current surface shape data and ideal surface shape parameters of the element to be polished, wherein the surface structure parameters of the element to be polished include the current surface shape data and the ideal surface shape parameters; determining the material removal distribution function of the target processing cycle based on the current surface shape data and the ideal surface shape parameters; determining the polishing path, the dwell points on the polishing path, and the dwell time corresponding to the dwell points based on the preset polishing parameters and the material removal distribution function, so as to polish the element to be polished within the target processing cycle.

[0009] The polishing method provided by the embodiment of the present invention determines the polishing path, the dwell points on the polishing path, and the dwell times corresponding to the dwell points based on preset polishing parameters and a material removal distribution function. The method further includes: performing simulated polishing based on the polishing path, the dwell points, and the dwell time to obtain a simulated polishing result; when the simulated polishing result meets the qualified conditions determined based on the ideal surface parameters, the preset polishing parameters, the polishing path, the dwell points, and the dwell time are used to polish the to-be-polished component within a target processing cycle; when the simulated polishing result does not meet the qualified conditions, new preset polishing parameters are set, and new polishing paths, new dwell points, and new dwell times are determined based on the new preset polishing parameters and the material removal distribution function to obtain a new simulated polishing result, and it is determined whether the new simulated polishing result meets the qualified conditions.

[0010] The polishing method provided by the embodiment of the present invention determines the polishing path, the dwell points on the polishing path, and the dwell time corresponding to the dwell points based on preset polishing parameters and a material removal distribution function, including: determining a tool influence function based on the preset polishing parameters, and planning an initial path, wherein the convolution of the tool influence function and the dwell time is related to the material removal distribution function; determining a vector representation corresponding to the dwell time based on the tool influence function and the material removal distribution function; parameterizing the dwell time graph corresponding to the vector representation into a B-spline surface based on a B-spline basis function algorithm, obtaining a surface expression for the dwell time, and a target function corresponding to the surface expression; solving the target function based on an optimization algorithm, obtaining the coordinates of the dwell points and the corresponding dwell time, wherein the coordinates of the dwell points are coordinates in a workpiece coordinate system determined based on the element to be polished; and determining the polishing path based on the initial path and the coordinates of the dwell points.

[0011] The polishing method provided by the embodiment of the present invention has an optimization algorithm including a least squares method and a node position optimization algorithm, and an objective function including a residence time smoothing function and a curvature fitting function; the objective function is solved based on the optimization algorithm to obtain the coordinates of the residence point and the corresponding residence time, including: solving the residence time smoothing function based on the least squares method to obtain a global mapping value, wherein the global mapping value is related to the control vertex vector of the B-spline surface and is used to characterize the global fitting accuracy of the residence time graph; solving the curvature fitting function based on the node position optimization algorithm to obtain a local mapping value, wherein the local mapping value is related to the node vector of the B-spline surface and is used to characterize the local fitting accuracy of the residence time graph; determining the coordinates of the residence point and the corresponding residence time based on the global mapping value and the local mapping value.

[0012] The polishing method provided by the embodiment of the present invention performs feedback control on the polishing equipment according to the applied force and position information until the polishing equipment completes the polishing path. The above method also includes: detecting the surface accuracy of the target element, wherein the target element is the element obtained by polishing the polishing element by the polishing equipment according to the polishing path; if the surface accuracy of the target element does not reach a preset threshold, the target element is placed in a preset position, the target element is polished through a new polishing path to obtain a new target element, and the surface accuracy of the new target element is detected.

[0013] The polishing method provided by the embodiment of the present invention comprises an element to be polished including an initial polishing element and a mechanical polishing element, a polishing path including a mechanical polishing path and a plasma polishing path, and a polishing device including a mechanical polishing device and a plasma polishing device; the element to be polished is placed in a preset position, and the element to be polished is polished according to the polishing path, comprising: placing the initial polishing element in a mechanical polishing position, and using the mechanical polishing device to mechanically polish the initial polishing element according to the mechanical polishing path to obtain a mechanical polishing element, wherein the mechanical polishing path is determined based on the surface structure parameters of the initial polishing element; placing the mechanical polishing element in a plasma polishing position, and using the plasma polishing device to plasma polish the mechanical polishing element according to the plasma polishing path, wherein the plasma polishing path is determined based on the surface structure parameters of the mechanical polishing element, and the element obtained after the plasma polishing is completed is the target element.

[0014] The present invention provides a polishing system according to an embodiment of the present invention, including a workpiece clamping device, a collection device, a polishing device and a control system; the workpiece clamping device is controlled by the control system to place the element to be polished at a preset position; the collection device obtains the surface structure parameters of the element to be polished, obtains the position information of the polishing device and the force exerted by the polishing device on the element to be polished during the polishing process, and transmits the surface structure parameters, position information and force to the control system; wherein the position information is used to adjust the force; the polishing device is controlled by the control system to polish the element to be polished according to the polishing path; the control system generates a polishing path according to the surface structure parameters, and performs feedback control on the polishing device according to the force and position information until the polishing device completes the polishing path.

[0015] The polishing system provided by the embodiment of the present invention comprises elements to be polished including initial polishing elements, mechanical polishing elements and intermediate polishing elements, and the polishing equipment comprises mechanical polishing equipment and plasma polishing equipment. The polishing system further comprises a cleaning and drying device; the mechanical polishing equipment mechanically polishes the initial polishing elements to obtain mechanical polishing elements; the cleaning and drying device is controlled by a control system to clean and dry the mechanical polishing elements to obtain intermediate polishing elements; and the plasma polishing equipment performs plasma polishing on the intermediate polishing elements.

[0016] The present invention provides a polishing method and system that, during the polishing process, obtains the position information of the polishing equipment and the force exerted by the polishing equipment on the element to be polished, and performs feedback control on the polishing equipment based on the force and position information until the polishing equipment polishes the element to be polished into the target element, wherein the position information is used to adjust the force. Constant force polishing can be achieved by outputting the force through force feedback control, thereby achieving a balanced and stable polishing effect; adjusting the force through position feedback control to achieve smooth control is conducive to further improving polishing stability, thereby improving polishing accuracy and maintaining relatively stable polishing quality. This solves the problems of low polishing accuracy and unstable polishing quality in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive effort.

[0018] Figure 1 It is a step flow chart of a polishing method in an embodiment of the present invention.

[0019] Figure 2It is a logical diagram of constant force control in an embodiment of the present invention.

[0020] Figure 3 It is a module schematic diagram of a polishing system in an embodiment of the present invention.

[0021] Figure 4 It is a schematic diagram of the positions of the cleaning and drying device and the mechanical polishing equipment in the embodiment of the invention.

[0022] Figure 5 It is a schematic diagram of the positions of the mother disc that is not grasped by the male disc and the loading platform in the embodiment of the present invention.

[0023] Figure 6 It is a schematic diagram of the male disc grabbing the female disc in the embodiment of the present invention.

[0024] Figure 7 It is a structural diagram of an electronic device in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0026] Polishing methods are primarily divided into mechanical polishing and plasma polishing. Mechanical polishing relies on traditional equipment and processes, making it difficult to meet high-precision requirements and prone to scratches and subsurface damage. While plasma polishing offers higher polishing accuracy than mechanical polishing, it has stricter requirements for material and surface properties, and the technology is still immature, resulting in inconsistent polishing quality.

[0027] To do this, please refer to Figure 1 As shown, the present invention provides an embodiment of a polishing method, including steps S101 to S103.

[0028] In step S101 , a component to be polished is placed at a preset position, and the component to be polished is polished according to a polishing path, wherein the polishing path is determined according to surface structural parameters of the component to be polished.

[0029] Step S102 : During the polishing process, position information of the polishing device and the force exerted by the polishing device on the element to be polished are obtained, wherein the position information is used to adjust the force.

[0030] Step S103 , performing feedback control on the polishing device according to the force and position information until the polishing device completes the polishing path.

[0031] The component to be polished may be, but is not limited to, an optical component or a semiconductor material.

[0032] For example, glass and gallium nitride materials.

[0033] The preset position can be determined by those skilled in the art according to actual conditions.

[0034] For example, when the polishing method is mechanical polishing, the preset position is a position within the action area of ​​the mechanical polishing equipment, which needs to be determined in combination with the specific positions of the mechanical arm and polishing head of the mechanical polishing equipment.

[0035] The polishing path provided in this embodiment is determined before polishing and does not need to be adjusted during the polishing process, which helps to improve polishing efficiency and reduce control difficulty.

[0036] When applied to actual polishing processing, the above polishing path can be understood as corresponding to the polishing cycle.

[0037] For example, one polishing path corresponds to one polishing cycle, or one polishing path corresponds to multiple polishing cycles. This embodiment will be described below using one polishing path corresponding to one polishing cycle as an example.

[0038] In addition, compared with the related polishing path determination method, the method of determining the polishing path according to the surface structure parameters of the element to be polished in this embodiment helps to improve the polishing efficiency and polishing accuracy by parameterizing the dwell time diagram and improving the fitting accuracy of the dwell time diagram, which will be described in detail later.

[0039] The position information of the polishing device can be obtained by, but is not limited to, a displacement sensor, an angle sensor, a visual sensor, or an optical interferometer.

[0040] The force exerted by the polishing device on the element to be polished can be obtained through, but is not limited to, a pressure sensor or a torque sensor.

[0041] It should be noted that the movement of the polishing device is performed according to the polishing path. The above position information is used to adjust the force, rather than to control the movement of the polishing device.

[0042] The information collection frequency and control time interval for feedback control of the polishing device based on the force and position information can be set by those skilled in the art according to the material properties and machining accuracy requirements of the component to be polished.

[0043] The polishing method can be a composite polishing method. For example, the component to be polished is first subjected to a rough polishing process and then subjected to one or more fine polishing processes.

[0044] The distinction between rough polishing and fine polishing can refer to the conventional understanding of those skilled in the art, for example, based on the thickness of the material removed by polishing.

[0045] Whether it is rough polishing or fine polishing, polishing is performed according to the corresponding polishing path within the corresponding polishing cycle, and the polishing equipment is feedback controlled according to the corresponding force and position information, which helps to meet high precision requirements.

[0046] At the same time, it is also feasible for those skilled in the art to first perform a rough polishing according to relevant techniques, and then use the above polishing method provided in this embodiment to perform one or more fine polishings, which will not be described in detail in this embodiment.

[0047] In addition, this embodiment is subsequently described by taking the example of first performing mechanical polishing and then performing plasma polishing.

[0048] Among them, mechanical polishing can be understood as rough polishing, which helps to improve polishing efficiency, while plasma polishing can be understood as fine polishing, which helps to improve polishing accuracy and adaptability to components to be polished of different shapes.

[0049] By performing feedback control on the polishing equipment based on the applied force and position information, constant force and flexible polishing can be achieved, which can ensure relatively stable polishing quality for both mechanical polishing and plasma polishing, help reduce the number of polishing times and further improve polishing efficiency.

[0050] In summary, the polishing method provided in this embodiment obtains the position information of the polishing equipment and the force exerted by the polishing equipment on the element to be polished during the polishing process, and performs feedback control on the polishing equipment based on the force and position information until the polishing equipment polishes the element to be polished into the target element, wherein the position information is used to adjust the force. Constant force polishing by outputting the force through force feedback control can achieve a balanced and stable polishing effect; adjusting the force through position feedback control to achieve smooth control is conducive to further improving polishing stability, thereby improving polishing accuracy and maintaining relatively stable polishing quality. The above method can solve the problems of low polishing accuracy and unstable polishing quality in related technologies.

[0051] Preferably, in step S101, placing the component to be polished at a preset position and polishing the component to be polished according to the polishing path, the method further includes steps S001 to S003.

[0052] Step S001 : obtaining current surface shape data and ideal surface shape parameters of a component to be polished, wherein the surface structure parameters of the component to be polished include the current surface shape data and the ideal surface shape parameters.

[0053] The current topographic data is microscopic data at the micrometer or nanometer level, which can reflect the surface microscopic defects of the component to be polished.

[0054] For example, the scale of the current surface shape data is 1-100 nanometers, but it is obviously not limited to this.

[0055] The ideal surface parameters can be determined by those skilled in the art based on actual processing requirements of the component to be polished or data in a standard database.

[0056] Step S002 : determining a material removal distribution function of a target machining cycle based on current surface shape data and ideal surface shape parameters.

[0057] A workpiece coordinate system is established with the component to be polished, and the current surface shape data and the ideal surface shape parameters are expressed as coordinate points in the workpiece coordinate system. The workpiece coordinate system is provided with an x-direction and a y-direction.

[0058] Based on the information of the above coordinate points, a material removal distribution function is constructed to characterize the surface sampling points of the component to be polished. Material removal height at , the polishing head of the polishing equipment is at the residence point Dwell sampling point Material removal contribution at , polishing head at the dwell point Dwell time The corresponding relationship between them is shown in the following formula: ; in, Indicates the number of dwell points, Indicates the number of sampling points.

[0059] Step S003 , based on preset polishing parameters and the material removal distribution function, determining a polishing path, dwell points on the polishing path, and dwell times corresponding to the dwell points, for polishing the component to be polished within a target processing cycle.

[0060] The preset polishing parameters include, but are not limited to, polishing equipment type, path type, and working distance.

[0061] Those skilled in the art can determine the polishing path based on preset polishing parameters, and calculate the coordinates of each dwell point and the dwell time corresponding to each dwell point based on the material removal distribution function and the associated dwell time calculation method. Determining the polishing path and then calculating the dwell time can be accomplished by referring to existing techniques and will not be further described in this embodiment.

[0062] Steps S001 to S003 reflect a path planning method that takes dwell time into consideration. Compared with a path planning method based on fixed parameters and an adaptive path planning method based on real-time feedback, this method helps to perform targeted polishing and reduce the microscopic peak-to-valley value (PV value) and overall root mean square value (RMS value) of the component to be polished.

[0063] This embodiment further preferably determines the polishing path and the dwell time in a coordinated manner, rather than first determining the polishing path and then calculating the dwell time. For details, please refer to the following preferred manner of step S003.

[0064] Preferably, step S003, based on preset polishing parameters and material removal distribution function, determines the polishing path, the dwell points on the polishing path, and the dwell times corresponding to the dwell points, including steps S0031 to S0035.

[0065] Step S0031 : determining a tool influence function based on preset polishing parameters and planning an initial path, wherein the convolution of the tool influence function and the dwell time is related to the material removal distribution function.

[0066] Tool influence function TIF and polishing head at the dwell point Dwell sampling point Material removal contribution at Related.

[0067] The initial path may be, but is not limited to, a raster path or a pseudo-random path.

[0068] Step S0032: determining a vector representation corresponding to the dwell time based on the tool influence function and the material removal distribution function.

[0069] Step S0033: Based on the B-spline basis function algorithm, the dwell time graph corresponding to the vector representation is parameterized into a B-spline surface to obtain a surface expression for the dwell time and an objective function corresponding to the surface expression.

[0070] The surface expression for the dwell time is: ; in, is the residence time surface function, used to represent the residence time graph; Indicates the number of control vertices in the x direction, Indicates the number of control vertices in the y direction; represents the B-spline basis function on the knot vector X, express The order of represents the B-spline basis function on the knot vector Y, express The order of represents the control vertex that is located at the i-th in the x-direction and the j-th in the y-direction.

[0071] The objective function corresponding to the surface expression can be determined by those skilled in the art with reference to existing objective function determination methods, and can be used to solve the residence time. The objective function provided in this embodiment is preferably a residence time smoothing function and a curvature fitting function, which can take into account both global accuracy and local accuracy, as described in detail later.

[0072] Step S0034 , solving the objective function based on the optimization algorithm to obtain the coordinates of the dwell point and the corresponding dwell time, wherein the coordinates of the dwell point are coordinates in the workpiece coordinate system determined based on the component to be polished.

[0073] Step S0035 : determining the polishing path based on the initial path and the coordinates of the dwell point.

[0074] Preferably, the optimization algorithm includes a least squares method and a node position optimization algorithm, and the objective function includes a residence time smoothing function and a curvature fitting function.

[0075] Step S0034, solving the objective function based on the optimization algorithm to obtain the coordinates of the dwell point and the corresponding dwell time, including steps S00341 to S00343.

[0076] Step S00341 , solving the dwell time smoothing function based on the least squares method to obtain a global mapping value, wherein the global mapping value is related to the control vertex vector of the B-spline surface and is used to characterize the global fitting accuracy of the dwell time graph.

[0077] The dwell time smoothing function is: ; ; ; in, Represents the control vertex vector; Represents the balance parameter, which is used to adjust the weight of accuracy and smoothness; represents any real number, represents the target material removal distribution vector, represents the basis function matrix, represents the norm, represents the surface coverage area, represents the second-order partial derivative of the surface in the x direction, Represents the second-order partial derivative of the surface in a mixed direction based on the x-direction and the y-direction, Represents the second-order partial derivative of the surface in the y direction.

[0078] Step S00342: Solve the curvature fitting function based on the node position optimization algorithm to obtain a local mapping value, wherein the local mapping value is related to the node vector of the B-spline surface and is used to characterize the local fitting accuracy of the residence time graph.

[0079] The curvature fitting function is: ; ; ; in, represents the nodes in the node vector X; represents the nodes in the node vector Y; Represents the cumulative curvature and mean of each subdomain The sum of squared deviations of is used to minimize the complexity difference between subdomains; represents the average value of the cumulative curvature of all subdomains; and Indicates a subdomain mid-surface point The principal curvature of the surface is used to characterize the surface points The geometric complexity of .

[0080] The least squares method and the node position optimization algorithm belong to existing optimization algorithms. Solving the corresponding objective function based on the least squares method and the node position optimization algorithm belongs to the existing technology and will not be described in detail in this embodiment.

[0081] Step S00343: Determine the coordinates of the dwell point and the corresponding dwell time based on the global mapping value and the local mapping value.

[0082] The above solution provided in this embodiment can suppress high-frequency fluctuations of the dwell time surface and improve polishing stability by solving the dwell time smoothing function; and can optimize matching geometric features, reduce edge residuals, and improve polishing accuracy by solving the curvature fitting function.

[0083] Preferably, in step S003, after determining the polishing path, the dwell points on the polishing path, and the dwell times corresponding to the dwell points based on the preset polishing parameters and the material removal distribution function, the method further comprises: performing simulated polishing based on the polishing path, the dwell points, and the dwell times to obtain simulated polishing results.

[0084] When the simulated polishing result meets the qualification conditions determined based on the ideal surface parameters, the preset polishing parameters, polishing path, dwell point, and dwell time are used to polish the component to be polished within the target processing cycle.

[0085] When the simulated polishing result does not meet the qualification conditions, new preset polishing parameters are set, and based on the new preset polishing parameters and the material removal distribution function, a new polishing path, a new dwell point, and a new dwell time are determined to obtain a new simulated polishing result, and it is determined whether the new simulated polishing result meets the qualification conditions.

[0086] It is understandable that applying the preset polishing parameters, polishing path, dwell point and dwell time obtained through simulated polishing to actual polishing can improve the accuracy of actual polishing, help reduce the number of actual polishing passes, and thus improve polishing efficiency.

[0087] Preferably, the element to be polished includes an initial polishing element and a mechanical polishing element, the polishing path includes a mechanical polishing path and a plasma polishing path, and the polishing equipment includes a mechanical polishing equipment and a plasma polishing equipment.

[0088] Step S101 , placing a component to be polished at a preset position, and polishing the component to be polished according to a polishing path, including steps S1011 to S1012 .

[0089] Step S1011 , placing the initial polishing element in a mechanical polishing position, and using a mechanical polishing device to mechanically polish the initial polishing element according to a mechanical polishing path to obtain a mechanical polishing element, wherein the mechanical polishing path is determined according to surface structure parameters of the initial polishing element.

[0090] Step S1012: placing the mechanical polishing element in a plasma polishing position, and using a plasma polishing device to perform plasma polishing on the mechanical polishing element according to a plasma polishing path, wherein the plasma polishing path is determined according to surface structure parameters of the mechanical polishing element.

[0091] It can be understood that, in the above preferred embodiment, the component obtained after plasma polishing is the target component.

[0092] During the mechanical polishing process, the first position information of the mechanical polishing device and the first force of the mechanical polishing device on the initial polishing element are obtained, and the mechanical polishing device is feedback controlled according to the first force and the first position information until the mechanical polishing device completes the mechanical polishing path.

[0093] During the plasma polishing process, the second position information of the plasma polishing equipment and the second force of the plasma polishing equipment on the mechanical polishing element are obtained, and the plasma polishing equipment is feedback controlled according to the second force and the second position information until the plasma polishing equipment completes the plasma polishing path.

[0094] On the basis of the above-mentioned polishing method provided in this embodiment, by adopting a composite polishing method of first performing mechanical polishing and then performing plasma polishing, the advantages of high polishing efficiency, good surface adaptability, high polishing accuracy and relatively stable polishing quality can be taken into account.

[0095] Preferably, step S103 is to perform feedback control on the polishing device according to the force and position information until the polishing device completes the polishing path, including steps S1031 to S1034. Figure 2 The control logic block diagram is shown.

[0096] Step S1031, according to the force and expectation Determine the error force , where expectation It is determined according to the process requirements of the component to be polished.

[0097] Step S1032, based on the error force , proportional gain , differential gain , determine the force control signal , where the proportional gain and differential gain Affected by adaptive parameters Adjustment, adaptive parameters Related to the polishing environment.

[0098] ; in, Indicates time.

[0099] By setting the proportional gain Can improve response speed.

[0100] By setting the differential gain It can suppress overshoot and improve control accuracy.

[0101] In the actual polishing environment, there will be interference sources that affect the control and adjustment of polishing force. It can reduce the impact of interference sources. Adaptive parameters , The specific value of can be determined by those skilled in the art according to the actual polishing environment.

[0102] By using the polishing method provided in this embodiment, the root mean square value (RMS value) of the entire component to be polished can be reduced to 5 nanometers.

[0103] Please refer to Figure 2 As shown, in order to suppress noise, the error force Filter and get the force error , based on the force error The force control signal Make adjustments.

[0104] Step S1033: Based on the location information and desired location Determine force adjustment signal , where location information is the actual position of the end effector of the polishing equipment's robotic arm, the expected position It is determined according to the polishing path.

[0105] Specifically, based on location information and desired location The position deviation can be obtained .

[0106] According to position deviation Determine force adjustment signal The method can refer to the above error-based Determine force control signal It can also be a proportional control method or a proportional-integral-differential control method.

[0107] In addition, based on positive kinematics, the actual position of the end effector can be calculated by the joint states corresponding to the robotic arm of the polishing device, which will not be described in detail in this embodiment.

[0108] Step S1034: Based on the force control signal Control the force applied by the robot arm to the component to be polished and adjust the signal through the force The applied force is adjusted until the polishing equipment completes the polishing path.

[0109] The force applied by the robot arm to the component to be polished is controlled by a force control signal Main, force adjustment signal Supplementary.

[0110] For example, based on the force control signal The control is carried out continuously while the polishing equipment moves along the polishing path, and the force adjustment signal is Adjustment is done on position deviation This is done when a preset deviation threshold is reached.

[0111] Alternatively, the force adjustment signal Multiplying with the adjustment factor to obtain the force influence signal, based on the force influence signal and the force control signal Continuous control is performed as the polishing equipment moves along the polishing path. The adjustment factor is determined based on the material of the component being polished and the type of polishing equipment, and is greater than 0 and less than 1. For components of the same material being polished, the adjustment factor for mechanical polishing is greater than that for plasma polishing.

[0112] It is understandable that the force control signal The specific control object and force adjustment signal The specific adjustment objects may be, but are not limited to, the magnitude of the force, the magnitude of the torque, the joint angle of the robotic arm, and the movement speed.

[0113] The control or adjustment method based on the above signal can be, but is not limited to: converting the above signal into joint angle / speed instructions of a polishing device such as a robot based on inverse kinematics, and the joint motor of the robot executes the above instructions to drive the robot arm to move.

[0114] Furthermore, when mechanical polishing is used, the aforementioned force directly contacts the component in the form of polishing force. When plasma polishing is used, the aforementioned force indirectly contacts the component in the form of polishing energy. The difference in the force's manifestation does not materially affect the execution of the method provided in this embodiment.

[0115] Preferably, in step S103, feedback control is performed on the polishing device according to the applied force and position information until the polishing device completes the polishing path. The above method further includes: detecting the surface accuracy of the target element, wherein the target element is an element obtained by polishing the element to be polished by the polishing device according to the polishing path; if the surface accuracy of the target element does not reach a preset threshold, the target element is placed in a preset position, the target element is polished through a new polishing path to obtain a new target element, and the surface accuracy of the new target element is detected.

[0116] The above-mentioned preset threshold value can be set by those skilled in the art according to actual process requirements or data in a standard database.

[0117] When the polishing of the element to be polished needs to be achieved through multiple polishing cycles, the target element obtained in the previous polishing cycle is the element to be polished in the adjacent polishing cycle after the above-mentioned previous polishing cycle. At the end of each polishing cycle, the corresponding target element obtained is subjected to surface accuracy detection until the target element whose surface accuracy reaches the preset threshold is obtained.

[0118] It is understandable that precision testing of target components can ensure that the components obtained by polishing meet process requirements and improve the yield rate.

[0119] Please refer to Figure 3 As shown, an embodiment of the present invention further provides a polishing system, including a workpiece clamping device 31 , a collection device 32 , a polishing device 33 and a control system 34 .

[0120] The workpiece clamping device 31 is controlled by the control system 34 to place the component to be polished at a preset position.

[0121] The acquisition device 32 obtains the surface structural parameters of the element to be polished; obtains the position information of the polishing equipment during the polishing process, and the force exerted by the polishing equipment on the element to be polished; transmits the surface structural parameters, position information and force to the control system 34; wherein the position information is used to adjust the force.

[0122] The polishing device 33 is controlled by the control system 34 and polishes the component to be polished according to the polishing path.

[0123] The control system 34 generates a polishing path according to the surface structure parameters; and performs feedback control on the polishing device 33 according to the force and position information until the polishing device 33 completes the polishing path.

[0124] The collecting device 32 and the polishing device 33 can be integrated into an integrated polishing device.

[0125] The acquisition device 32 includes but is not limited to a displacement sensor and a pressure sensor.

[0126] The polishing device 33 includes but is not limited to a mechanical arm equipped with a polishing head, a polishing wheel, or a polishing nozzle, a drive motor, and a force control module. The force control module receives a control signal from the control system 34 and controls the mechanical arm and / or the drive motor.

[0127] In the polishing system provided in this embodiment, during the polishing process, an acquisition device 32 acquires position information of a polishing device 33 and the force applied by the polishing device 33 to the element being polished. A control system 34 provides feedback control over the polishing device 33 based on the force and position information until the element being polished is polished to the target element. The position information is used to adjust the force. Constant-force polishing achieved by outputting force through force feedback control achieves a balanced and stable polishing effect. Adjusting the force through position feedback control achieves compliant control, further improving polishing stability, thereby increasing polishing accuracy and maintaining relatively stable polishing quality.

[0128] The polishing system provided in this embodiment can be understood with reference to the polishing method described above.

[0129] Preferably, the element to be polished includes an initial polishing element, a mechanical polishing element and an intermediate polishing element, the polishing equipment 33 includes a mechanical polishing equipment and a plasma polishing equipment, and the above-mentioned polishing system also includes a cleaning and drying device.

[0130] Mechanical polishing equipment is used to mechanically polish the initial polishing element to obtain a mechanical polishing element.

[0131] The cleaning and drying device is controlled by the control system 34 to clean and dry the mechanical polishing element to obtain an intermediate polishing element.

[0132] Plasma polishing equipment, plasma polishing of intermediate polishing components.

[0133] Specifically, mechanical polishing is performed in a cerium oxide solution and is considered wet polishing. Plasma polishing, performed under a plasma flame, is considered dry polishing. Therefore, during the combined mechanical and plasma polishing process, the surface of the mechanically polished component must be cleaned and dried before plasma polishing can proceed.

[0134] For example, the polishing wheel of the mechanical polishing device has a rotation speed of 1000-3000 rpm. The plasma polishing device uses argon as the working gas, and the plasma power is 200-500W.

[0135] Furthermore, the above-mentioned plasma polishing equipment is an atmospheric plasma polishing equipment, which does not require the assistance of vacuum equipment and has the advantages of relatively simple operation and high processing efficiency.

[0136] Furthermore, the cleaning and drying device includes a rinsing nozzle and a drying nozzle. The rinsing nozzle is used to clean the surface of the mechanical polishing element, and the drying nozzle is used to dry the cleaned mechanical polishing element to obtain the intermediate polishing element. Please refer to the positional relationship between the grinding head of the polishing wheel of the mechanical polishing equipment and the rinsing nozzle and the drying nozzle. Figure 4 shown.

[0137] Preferably, the workpiece clamping device 31 includes a male disc and a female disc, the female disc is provided with a zero point positioning fixture, and the male disc is provided with a gripper for locking with the female disc.

[0138] Please refer to Figure 5 and Figure 6 As shown in the figure, before polishing, the operator clamps the component to be polished on the zero-point positioning fixture of the master plate and then places the master plate on the loading platform. The robot arm locks with the master plate through the gripper of the male plate to grab the component to be polished and place it in the preset position.

[0139] Optionally, the control system 34 is an electronic device comprising: at least one processor; and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, and when executed by the at least one processor, the computer program causes the electronic device to perform the control method of the control system 34 provided in an embodiment of the present invention.

[0140] like Figure 7 As shown, the electronic device includes a computing unit 701, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 702 or a computer program loaded from a storage unit 708 into a random access memory (RAM) 703. RAM 703 can also store various programs and data required for the operation of the electronic device. The computing unit 701, ROM 702, and RAM 703 are interconnected via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0141] Multiple components within the electronic device are connected to the I / O interface 705, including an input unit 706, an output unit 707, a storage unit 708, and a communication unit 709. The input unit 706 can be any type of device capable of inputting information into the electronic device. The input unit 706 can receive input digital or character information and generate key signal inputs related to user settings and / or function control of the electronic device. The output unit 707 can be any type of device capable of presenting information and can include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 708 can include, but is not limited to, a magnetic disk or an optical disk. The communication unit 709 allows the electronic device to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks and can include, but is not limited to, a modem, a network card, an infrared communication device, and / or a wireless communication transceiver, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0142] The computing unit 701 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Examples of the computing unit 701 include, but are not limited to, a CPU, a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing units, various computing units for running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, and the like.

[0143] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, they should be understood as "one or more". The descriptions of the terms "first", "second", etc. are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0144] The various steps described in the method implementation methods provided by the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0145] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0146] The above-described embodiments merely represent several implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A polishing method, characterized in that: include: Placing the element to be polished at a preset position, and polishing the element to be polished according to a polishing path, wherein the polishing path is determined according to surface structural parameters of the element to be polished; During the polishing process, obtaining position information of the polishing device and the force exerted by the polishing device on the element to be polished, wherein the position information is used to adjust the force; Feedback control is performed on the polishing device according to the applied force and the position information until the polishing device completes the polishing path.

2. The method according to claim 1, characterized in that Feedback controlling the polishing device according to the applied force and the position information until the polishing device completes the polishing path includes: determining an error force based on the applied force and an expected force, wherein the expected force is determined based on a process requirement of the component to be polished; determining a force control signal based on the error force, a proportional gain, and a differential gain, wherein the proportional gain and the differential gain are adjusted by adaptive parameters, and the adaptive parameters are related to the polishing environment; determining a force adjustment signal according to the position information and a desired position, wherein the position information is an actual position of an end effector of a robotic arm of the polishing device, and the desired position is determined according to the polishing path; The force applied by the robot arm to the component to be polished is controlled based on the force control signal, and the applied force is adjusted by the force adjustment signal until the polishing device completes the polishing path.

3. The method according to claim 1, characterized in that Before placing the element to be polished at a preset position and polishing the element to be polished according to the polishing path, the method further comprises: Acquiring current surface shape data and ideal surface shape parameters of the component to be polished, wherein the surface structure parameters of the component to be polished include the current surface shape data and the ideal surface shape parameters; Determining a material removal distribution function for a target machining cycle based on the current surface shape data and the ideal surface shape parameters; Based on preset polishing parameters and the material removal distribution function, the polishing path, dwell points on the polishing path, and dwell times corresponding to the dwell points are determined for polishing the component to be polished within the target processing cycle.

4. The method according to claim 3, characterized in that After determining the polishing path, dwell points on the polishing path, and dwell times corresponding to the dwell points based on preset polishing parameters and the material removal distribution function, the method further includes: Performing simulated polishing based on the polishing path, the dwell point, and the dwell time to obtain a simulated polishing result; When the simulated polishing result meets the qualification condition determined based on the ideal surface shape parameter, the preset polishing parameters, the polishing path, the dwell point, and the dwell time are used to polish the component to be polished within the target processing cycle; If the simulated polishing result does not meet the qualification conditions, new preset polishing parameters are set, and based on the new preset polishing parameters and the material removal distribution function, a new polishing path, a new dwell point, and a new dwell time are determined to obtain a new simulated polishing result, and it is determined whether the new simulated polishing result meets the qualification conditions.

5. The method according to claim 3, characterized in that Determining the polishing path, dwell points on the polishing path, and dwell times corresponding to the dwell points based on preset polishing parameters and the material removal distribution function includes: Determining a tool influence function based on the preset polishing parameters and planning an initial path, wherein a convolution of the tool influence function and the dwell time is related to the material removal distribution function; determining a vector representation corresponding to the dwell time based on the tool influence function and the material removal distribution function; Based on a B-spline basis function algorithm, the dwell time graph corresponding to the vector representation is parameterized into a B-spline surface, and a surface expression for the dwell time and an objective function corresponding to the surface expression are obtained; Solving the objective function based on an optimization algorithm to obtain the coordinates of the dwell point and the corresponding dwell time, wherein the coordinates of the dwell point are coordinates in a workpiece coordinate system determined based on the component to be polished; The polishing path is determined based on the initial path and the coordinates of the dwell point.

6. The method according to claim 5, characterized in that The optimization algorithm includes the least square method and the node position optimization algorithm, and the objective function includes the residence time smoothing function and the curvature fitting function; Solving the objective function based on an optimization algorithm to obtain the coordinates of the dwell point and the corresponding dwell time includes: Solving the dwell time smoothing function based on the least squares method to obtain a global mapping value, wherein the global mapping value is related to the control vertex vector of the B-spline surface and is used to characterize the global fitting accuracy of the dwell time graph; Solving the curvature fitting function based on the node position optimization algorithm to obtain a local mapping value, wherein the local mapping value is related to the node vector of the B-spline surface and is used to characterize the local fitting accuracy of the dwell time graph; The coordinates of the dwell point and the corresponding dwell time are determined based on the global mapping value and the local mapping value.

7. The method according to claim 1, characterized in that Feedback controlling the polishing device according to the applied force and the position information until the polishing device completes the polishing path, the method further comprising: Detecting the surface accuracy of a target element, wherein the target element is an element obtained by polishing the element to be polished by the polishing device according to the polishing path; When the surface accuracy of the target element does not reach a preset threshold, the target element is placed in the preset position, polished through a new polishing path to obtain a new target element, and the surface accuracy of the new target element is tested.

8. The method according to claim 1, characterized in that The element to be polished includes an initial polishing element and a mechanical polishing element, the polishing path includes a mechanical polishing path and a plasma polishing path, and the polishing equipment includes a mechanical polishing equipment and a plasma polishing equipment; Placing a component to be polished at a preset position and polishing the component to be polished according to a polishing path, comprising: placing the initial polishing element in a mechanical polishing position, and using the mechanical polishing equipment to mechanically polish the initial polishing element according to the mechanical polishing path to obtain the mechanical polishing element, wherein the mechanical polishing path is determined according to the surface structure parameters of the initial polishing element; The mechanical polishing element is placed in a plasma polishing position, and the plasma polishing equipment is used to perform plasma polishing on the mechanical polishing element according to the plasma polishing path, wherein the plasma polishing path is determined according to the surface structure parameters of the mechanical polishing element.

9. A polishing system, characterized in that: Including workpiece clamping device, collection device, polishing equipment and control system; The workpiece clamping device is controlled by the control system to place the component to be polished at a preset position; The acquisition device acquires the surface structural parameters of the element to be polished; Acquiring position information of the polishing device during the polishing process, and the force exerted by the polishing device on the element to be polished; Transmitting the surface structure parameters, the position information and the action force to the control system; wherein the position information is used to adjust the action force; The polishing device is controlled by the control system to polish the element to be polished according to the polishing path; The control system generates the polishing path according to the surface structure parameters; and performs feedback control on the polishing device according to the force and the position information until the polishing device completes the polishing path.

10. The polishing system according to claim 9, characterized in that The elements to be polished include initial polishing elements, mechanical polishing elements and intermediate polishing elements; the polishing equipment includes mechanical polishing equipment and plasma polishing equipment; and the polishing system further includes a cleaning and drying device; The mechanical polishing device mechanically polishes the initial polishing element to obtain the mechanical polishing element; The cleaning and drying device is controlled by the control system to clean and dry the mechanical polishing element to obtain the intermediate polishing element; The plasma polishing equipment performs plasma polishing on the intermediate polishing element.

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