Space-time regulation and control grinding and polishing method and device for anisotropic thin-wall curved surface workpiece

Abstract

The invention relates to a space-time regulation and control grinding and polishing method and device for an anisotropic thin-wall curved-surface workpiece, and belongs to the field of ultra-precision polishing. The method comprises the steps that the anisotropic thin-wall curved-surface workpiece is fixed to a multi-axis parallel motion platform; based on the machining postures of the flexible machining tool at all the machining points and the machining crystal face of the anisotropic thin-wall curved surface workpiece, the space displacement regulation and control amount and the material removal rate of the flexible machining tool at the machining points are calculated; deconvolution is carried out on the basis of the material removal rate and the target removal volume to calculate the residence time of the flexible machining tool at the corresponding machining point; the flexible machining tool is regulated and controlled on the basis of the space displacement regulation and control amount and the residence time of the flexible machining tool, the removal difference of the anisotropic thin-wall curved surface workpiece under different machining postures and machining crystal faces is adaptively eliminated, high-precision controllable grinding and polishing are achieved, the uniform material removal rate is guaranteed, controllable material removal is achieved, and the machining precision of the anisotropic thin-wall curved surface workpiece is improved. The workpiece is fixed in a mode of only constraining the boundary, so that stress deformation generated after the workpiece is separated from the tool is avoided.

Description

Technical Field

[0001] The invention belongs to the field of ultra-precision polishing, and in particular relates to a time-space controlled polishing method and a device for anisotropic thin-wall curved surface workpieces. Background Art

[0002] Anisotropic thin-walled curved workpieces are widely used in the automotive industry, aerospace, military field, medical equipment, shipbuilding and other fields; due to the special shape of anisotropic thin-walled curved workpieces, their surface quality directly affects their function and appearance, so surface quality control is one of the key issues in the processing process. However, for this type of original parts, the curvature change and the anisotropic characteristics of material removal lead to different material removal in different processing postures and processing crystal surfaces during the processing process. There are still many difficulties in achieving the process requirements of controllable processing and high surface integrity.

[0003] Due to the material and structural characteristics of anisotropic thin-walled curved workpieces, traditional grinding wheel processing methods are very likely to cause workpiece fragmentation and uneven material removal. Therefore, the current traditional processing method for anisotropic thin-walled curved workpieces is to remove materials by combining mechanical force or chemical modification, such as ultra-precision cutting, ion beam polishing, electron beam polishing, magnetorheological polishing and other grinding and polishing methods. In ultra-precision grinding, in order to adapt to the curvature changes and thin-wall features of the workpiece, one way is to completely fit the workpiece on the tooling for cutting at a fixed depth. Due to hard contact, the tooling will apply residual stress to the workpiece, resulting in surface changes after the workpiece is separated from the tooling; similarly, since the material will recover elastically after processing, this processing method still cannot avoid the processing differences of anisotropic materials on different processing crystal surfaces. Although non-contact processing methods such as ion beam polishing, electron beam polishing and magnetorheological polishing have sub-nanometer processing accuracy and can adapt to the curvature changes and overload-prone breakage characteristics of such workpieces, this method is usually used as the last processing step. The reason is that the equipment of this processing method is expensive, the processing efficiency is low, and the material removal difference during the anisotropic material removal process cannot be predicted.

[0004] Therefore, for the processing of anisotropic thin-walled surfaces, it is necessary to consider the anisotropy of material load deformation and removal, as well as the curvature change of the surface at the processing point and the fragility of thin-walled materials. The flexible contact polishing method can achieve adaptive flexible processing of the surface due to the deformation of the tool, avoid the fragility of overloaded materials, and the equipment is simple and has high-precision processing capabilities. However, the removal difference of anisotropic materials in polishing is still unpredictable, and stress deformation caused by hard tooling contact will still occur. Summary of the invention

[0005] The purpose of the present invention is to provide a time-space controlled grinding and polishing method and device for anisotropic thin-walled curved surface workpieces, so as to solve the problems of anisotropy in material removal, easy breakage of thin-wall features, difficult processing of curved surfaces, and difficulty in easily achieving high-precision controllable surface forming during the processing of anisotropic thin-walled curved surface workpieces.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is: The present invention relates to a time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces, which comprises the following steps: The crystal orientation and crystal plane orientation of the anisotropic thin-walled curved surface workpiece are measured, and the anisotropic thin-walled curved surface workpiece is fixed on a multi-axis parallel motion platform, and a corresponding processing posture is selected to make the processing linear velocity direction of the flexible processing tool consistent with the crystal orientation of the processing point position of the anisotropic thin-walled curved surface workpiece; Based on the machining posture of the flexible machining tool at each machining point and the machining crystal surface of the anisotropic thin-walled curved workpiece, the spatial displacement control amount and material removal rate of the flexible machining tool at the machining point are calculated; Deconvolution is performed based on the material removal rate and the target removal volume of the corresponding processing point to calculate the residence time of the flexible processing tool at the corresponding processing point; Based on the spatial displacement control amount and dwell time of the flexible machining tool at the corresponding machining point, the flexible machining tool is controlled to adaptively eliminate the removal differences of anisotropic thin-walled curved workpieces under different machining postures and machining crystal surfaces, thereby achieving high-precision controllable grinding and polishing.

[0007] Preferably, it comprises the following steps: S1: Detect and obtain the initial surface shape, crystal plane orientation and crystal direction orientation of the anisotropic thin-walled curved surface workpiece, fix the anisotropic thin-walled curved surface workpiece on a multi-axis parallel motion platform, select the processing posture of the flexible processing tool at each processing point based on the crystal direction orientation of the anisotropic thin-walled curved surface workpiece, and make the processing linear velocity direction of the flexible processing tool consistent with the crystal direction of the processing point position of the anisotropic thin-walled curved surface workpiece; S2: Based on the contact pressure field distribution of the flexible machining tool in the target machining area and the machining crystal surface, the spatial displacement control amount required after the flexible machining tool and the anisotropic thin-walled curved surface workpiece are deformed at each machining point is calculated; S3: setting the target surface shape result, determining the target material removal volume based on the initial surface shape and the target surface shape, and calculating the material removal rate when the flexible machining tool removes material from the machining crystal surface under the machining posture in combination with the contact pressure field and the machining parameters; S4: Calculate the residence time of the flexible machining tool at each machining point in the full-area grinding and polishing by deconvolution based on the target material removal volume and material removal rate; S5: The flexible machining tool is driven according to the spatial displacement control amount and the dwell time of the flexible machining tool at each machining point, and then the anisotropic thin-walled curved surface workpiece is subjected to full-area grinding and polishing.

[0008] Preferably, in S1, the anisotropic thin-walled curved workpiece is fixed on the multi-axis parallel motion platform by only constraining the boundaries. The only constraining boundaries fixation method refers to no support in the middle, and the edges are fixedly supported, simply supported, with set boundary conditions or freely clamped boundaries.

[0009] Preferably, the displacement control amount of the flexible processing tool in the space domain in S2 is The calculation formula is: (1) (2) (3) in, is the equivalent Young's modulus of the anisotropic thin-walled curved workpiece when the flexible machining tool removes material on the corresponding machining crystal surface. is the tool Poisson’s ratio, and are the distance and azimuth between the calculation point and the pressure position, respectively. is the equivalent radius of the flexible machining tool, Indicates the distance between the point in the pressure area and the processing point The distance is the pressure distribution at the processing point, The displacement control amount of the flexible machining tool is set to ensure a uniform pressure field distribution by considering the deformation of the workpiece and the tool. For processing point The deformation of the flexible processing tool, is the maximum deformation of the flexible processing tool, It is the deformation of the anisotropic thin-walled curved workpiece at the maximum deformation position of the flexible machining tool.

[0010] Preferably, the material removal rate calculation formula of the flexible processing tool in S3 is: (4) (5) (6) in, is the yield limit of the processed crystal direction, It is the material removal rate of a single abrasive grain on the machined crystal surface. It is the penetration depth of a single abrasive grain on the machined crystal surface to remove material. is the flexible machining tool speed, is the material removal rate of all abrasive particles at the processing point, is the number of abrasive particles, To set the abrasive radius.

[0011] Preferably, the residence time of the flexible processing tool in the full-area grinding and polishing in S4 at each processing point that needs to be regulated in the time domain is The calculation formula is: (7) in, For processing point The processing time at For processing point The target removal volume at is the deconvolution calculation symbol, For processing point The pressure exerted on the abrasive particles at the

[0012] Preferably, in S2, the maximum deformation of the flexible machining tool is set to be less than 20% of the thickness of the machined workpiece.

[0013] Preferably, in S2, the pressure exerted by the flexible processing tool on the anisotropic thin-walled curved surface workpiece is set to be no greater than three times the yield stress limit of the flexible processing tool and the processing crystal surface material under the selected processing posture.

[0014] The present invention also relates to a time-space controlled grinding and polishing device for anisotropic thin-walled curved surface workpieces, which includes a multi-axis parallel motion platform, a controller, a calculator and a flexible processing tool; The multi-axis parallel motion platform is used to fix anisotropic thin-walled curved surface workpieces and flexible processing tools; The calculator calculates the spatial displacement control amount and material removal rate of the flexible machining tool at each machining point based on the machining posture of the flexible machining tool at each machining point and the machining crystal surface of the anisotropic thin-walled curved workpiece, calculates the residence time of the flexible machining tool at the corresponding machining point based on the material removal rate and the target removal volume of the corresponding machining point by deconvolution, and transmits the calculated spatial displacement control amount and residence time to the controller; The controller is used to drive the multi-axis parallel motion platform based on the spatial displacement control amount and dwell time of the flexible processing tool at the corresponding processing point, so that the linear velocity direction of the processing of the flexible processing tool is consistent with the crystal direction of the processing point position of the anisotropic thin-walled curved surface workpiece. At the same time, the flexible processing tool is controlled to adaptively eliminate the removal difference of the anisotropic thin-walled curved surface workpiece under different processing postures and processing crystal planes, thereby realizing high-precision controllable grinding and polishing.

[0015] Preferably, the multi-axis parallel motion platform includes a base, an X-axis motion platform, a Y-axis motion platform, a fixed tool, a frame, a crossbeam, a Z-axis motion platform, and a rotating axis. The flexible processing tool is fixed on the rotating axis and is used to grind and polish anisotropic thin-walled curved surface workpieces; the X-axis motion platform is connected above the base, the Y-axis motion platform is connected above the X-axis motion platform, the X-axis motion platform and the Y-axis motion platform are perpendicular to each other, the fixed tool is installed on the Y-axis motion platform, the fixed tool is used to fix the anisotropic thin-walled curved surface workpiece, and the linkage of the anisotropic thin-walled curved surface workpiece in the X-axis direction and the Y-axis direction is realized through the X-axis motion platform and the Y-axis motion platform, the crossbeam is installed on the base through the frame, the rotating axis is installed on the crossbeam, the Z-axis motion platform is installed on the rotating axis, the flexible processing tool is installed on the Z-axis motion platform, and the adjustment of the flexible processing tool on the Z-axis and the adjustment of the processing angle are respectively realized through the Z-axis motion platform and the rotating axis.

[0016] The flexible processing tool is a flexible tool such as an air bag.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows: 1. The time-space controlled grinding and polishing method for anisotropic thin-walled curved workpieces involved in the present invention is based on the processing posture of the flexible processing tool at each processing point and the processing crystal surface of the anisotropic thin-walled curved workpiece, calculates the spatial displacement control amount and material removal rate of the flexible processing tool at the processing point, and then deconvolutes the material removal rate and the target removal volume of the corresponding processing point to calculate the residence time of the flexible processing tool at the corresponding processing point. The spatial displacement control amount and the residence time are used as the basis for controlling the flexible processing tool to achieve controllable grinding and polishing; in the spatial domain, this method can adapt to the differences in the deformation of anisotropic materials on different crystal surfaces, and achieve a stable contact pressure field distribution in the entire domain, thereby ensuring a uniform material removal rate; in the time domain, the material removal differences of anisotropic materials during the processing process are adapted to by regulating the processing time, and controllable material removal is achieved.

[0018] 2. The time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces involved in the present invention fixes the anisotropic thin-walled curved surface workpiece on the tooling by only constraining the boundaries during the grinding and polishing process, thereby avoiding stress deformation caused by separation of the workpiece and the tooling, making the processed surface shape more accurate.

[0019] 3. The time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces uses flexible processing tools during the grinding and polishing process. The flexible processing tools can adapt to the processing difficulties of anisotropic thin-walled curved surface workpieces, such as difficult surface processing and easy breakage of thin-wall features. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a structural schematic diagram of a multi-axis parallel motion platform for realizing the time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces according to the present invention; Figure 2 It is a flow chart of the time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces; Figure 3 It is a schematic diagram of the fixing method of anisotropic thin-walled curved surface workpiece; Figure 4 It is a schematic diagram of spatial displacement control of different crystal surface processing tools; Figure 5 This is a schematic diagram of the processing time displacement control under different crystal planes and different processing postures.

[0021] In the figure: 1-base, 2-X-axis motion platform, 3-Y-axis motion platform, 4-fixed tooling, 5-frame, 6-beam, 7-Z-axis motion platform, 8-rotation axis, 9-flexible processing tool, 10-controller, 11-calculator. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention is further specifically described below through specific embodiments. The embodiments are for the purpose of explaining the present invention, not for limiting the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] The present invention relates to a method for time-space controlled grinding and polishing for anisotropic thin-walled curved workpieces. The method fixes the anisotropic thin-walled curved workpiece on a fixed tooling by only constraining the boundaries; in the spatial domain, the spatial displacement control amount of the flexible processing tool at the processing point is calculated; the material removal rate under the processing posture of the flexible processing tool is calculated; in the time domain, the residence time of the flexible processing tool at each processing point is calculated based on the material removal rate and the target removal volume of the processing point by deconvolution; based on the spatial displacement control amount and residence time of the flexible processing tool at the processing point, the flexible processing tool is driven to move by a multi-axis parallel motion platform, and the removal differences of the anisotropic thin-walled curved workpiece under different processing postures and processing crystal planes are adaptively eliminated to achieve high-precision controllable grinding and polishing. The specific structure of the time-space controlled grinding and polishing device for anisotropic thin-walled curved workpieces is as follows: Figure 1As shown, it includes a multi-axis parallel motion platform, a controller, a calculator and a flexible processing tool; the multi-axis parallel motion platform is used to fix the anisotropic thin-walled curved workpiece and the flexible processing tool 9; the calculator 11 calculates the spatial displacement control amount and material removal rate of the flexible processing tool at each processing point based on the processing posture of the flexible processing tool at each processing point and the processing crystal surface of the anisotropic thin-walled curved workpiece, and calculates the residence time of the flexible processing tool at the corresponding processing point by deconvolution based on the material removal rate and the target removal volume of the corresponding processing point, and transmits the calculated spatial displacement control amount and residence time to the controller; the controller 10 is used to drive the multi-axis parallel motion platform based on the spatial displacement control amount and residence time of the flexible processing tool at the corresponding processing point, so that the linear velocity direction of the flexible processing tool is consistent with the crystal direction of the processing point position of the anisotropic thin-walled curved workpiece, and at the same time adjusts the flexible processing tool to adaptively eliminate the removal difference of the anisotropic thin-walled curved workpiece under different processing postures and processing crystal surfaces, so as to achieve high-precision controllable grinding and polishing.

[0024] The multi-axis parallel motion platform includes a base 1, an X-axis motion platform 3, a Y-axis motion platform 2, a fixed tool 4, a frame 5, a beam 6, a Z motion platform 7, and a rotating shaft 8. The flexible processing tool 9 is fixed on the rotating shaft 8, and the flexible processing tool 9 is used to grind and polish anisotropic thin-walled curved surface workpieces; the X-axis motion platform 3 is connected above the base 1, and the Y-axis motion platform 2 is connected above the X-axis motion platform 3, and the X-axis motion platform 3 and the Y-axis motion platform 2 are perpendicular to each other. The fixed tool 4 is installed on the Y-axis motion platform 2, and the fixed tool 4 is used to fix the anisotropic thin-walled curved surface workpiece, and realize the linkage of the anisotropic thin-walled curved surface workpiece in the X-axis direction and the Y-axis direction through the X-axis motion platform and the Y-axis motion platform. The fixing method of the anisotropic thin-walled curved surface workpiece is a fixing method that only constrains the boundary. The fixing method that only constrains the boundary means that there is no support in the middle, and the edge is a fixed support, a simple support, a conditional boundary or a free clamping boundary. The crossbeam 6 is installed on the base 1 through the frame 5, the rotating shaft 8 is installed on the crossbeam 6, the Z-axis motion platform 7 is installed on the rotating shaft 8, and the flexible processing tool 9 is installed on the Z-axis motion platform 7. The adjustment of the flexible processing tool 9 on the Z-axis and the adjustment of the processing angle are respectively realized through the Z-axis motion platform 7 and the rotating shaft 8.

[0025] See attached Figure 2 The time-space controlled grinding and polishing method for anisotropic thin-walled curved surface workpieces specifically comprises the following steps: S0: Determine the processing parameters and parameters of anisotropic thin-walled curved workpieces, including the radius of the flexible processing tool, Young's modulus, Poisson's ratio, processing speed, processing posture, workpiece thickness, curvature change, processing crystal surface, polishing liquid particle size and concentration, etc.

[0026] S1: The initial surface shape, crystal plane orientation and crystal direction orientation of the anisotropic thin-walled curved surface workpiece are detected, and the anisotropic thin-walled curved surface workpiece is fixed on the fixed fixture of the multi-axis parallel motion platform by only constraining the boundary, such as Figure 3 As shown, the fixing method of the anisotropic thin-walled curved surface workpiece is that the middle is unsupported, and the edges are fixedly supported, simply supported, conditionally bounded, or freely clamped. The processing posture of the flexible processing tool at each processing point is selected based on the crystal orientation of the anisotropic thin-walled curved surface workpiece, so that the processing linear velocity direction of the flexible processing tool is consistent with the crystal orientation of the processing point of the anisotropic thin-walled curved surface workpiece. S2: Refer to the attached Figure 4 As shown, the contact pressure field distribution and processing crystal surface of the flexible processing tool in the target processing area are set, and the spatial displacement control amount that needs to be controlled in the spatial domain after the flexible processing tool and the anisotropic thin-walled curved surface workpiece are contacted and deformed at each processing point is calculated based on the contact pressure field distribution, the material and structural parameters of the anisotropic thin-walled curved surface workpiece, so as to compensate for the uneven pressure field distribution caused by the deformation of the thin-walled workpiece. In this step, the pressure of the flexible processing tool on the anisotropic thin-walled curved surface workpiece is not greater than 3 times the yield stress limit of the processing posture and the processing crystal surface material, and the deformation of the flexible processing tool on the workpiece should be in the elastic deformation range, that is, the maximum deformation is less than 20% of the thickness of the processed workpiece; Spatial displacement control of flexible processing tools The calculation formula is: (1) (2) (3) in, is the equivalent Young's modulus of the anisotropic thin-walled curved workpiece when the flexible machining tool removes material on the corresponding machining crystal surface. is the tool Poisson’s ratio, and are the distance and azimuth between the calculation point and the pressure position, respectively. is the equivalent radius of the flexible machining tool, Indicates the distance between the point in the pressure area and the processing point The distance is the pressure distribution at the processing point, The displacement control amount of the flexible machining tool is set to ensure a uniform pressure field distribution by considering the deformation of the workpiece and the tool. For processing point The deformation of the flexible processing tool, is the maximum deformation of the flexible processing tool, It is the deformation of the anisotropic thin-walled curved workpiece at the maximum deformation position of the flexible machining tool.

[0027] S3: Refer to the attached Figure 5 As shown in the figure, the target surface shape result is set, and the target material removal volume H is determined based on the initial surface shape and the target surface shape. The material removal rate when the flexible processing tool removes material from the processed crystal surface is calculated according to the initial surface shape, contact pressure field and processing parameters (such as processing posture and processing crystal surface, polishing liquid concentration, polishing liquid particle size, etc.). The calculation formula is: (4) (5) (6) in is the yield limit of the processed crystal direction, It is the material removal rate of a single abrasive grain on the machined crystal surface. It is the penetration depth of a single abrasive grain on the machined crystal surface to remove material. is the flexible machining tool speed, is the material removal rate of all abrasive particles at the processing point, To set the abrasive radius.

[0028] S4: Calculate the residence time of the flexible machining tool that needs to be regulated in the time domain at each machining point in the full-area grinding and polishing based on the target material removal volume and material removal rate , in order to compensate for the material removal differences of different crystal planes and crystal directions of different anisotropic thin-walled curved workpieces, the calculation formula is: (7) in, For processing point The processing time at for The target removal volume at is the deconvolution calculation symbol, For processing point The pressure exerted on the abrasive particles at the

[0029] S5: The calculator constructs a spatiotemporal control cloud map based on the spatial displacement control amount of the flexible machining tool in the spatial domain and the residence time of the flexible machining tool in the time domain. The controller starts the multi-axis parallel motion platform according to the spatiotemporal control cloud map, so that the multi-axis parallel motion platform drives the flexible machining tool according to the spatial displacement control amount of the flexible machining tool in the spatial domain and the residence time of the flexible machining tool in the time domain at each machining point, and then performs full-domain grinding and polishing on the anisotropic thin-walled curved surface workpiece.

[0030] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A time-space controlled grinding and polishing method for anisotropic thin-walled curved workpieces, characterized in that: It includes the following steps: The crystal orientation and crystal plane orientation of the anisotropic thin-walled curved surface workpiece are measured, and the anisotropic thin-walled curved surface workpiece is fixed on a multi-axis parallel motion platform, and a corresponding processing posture is selected to make the processing linear velocity direction of the flexible processing tool consistent with the crystal orientation of the processing point position of the anisotropic thin-walled curved surface workpiece; Based on the machining posture of the flexible machining tool at each machining point and the machining crystal surface of the anisotropic thin-walled curved workpiece, the spatial displacement control amount and material removal rate of the flexible machining tool at the machining point are calculated; Deconvolution is performed based on the material removal rate and the target removal volume of the corresponding processing point to calculate the residence time of the flexible processing tool at the corresponding processing point; Based on the spatial displacement control amount and dwell time of the flexible machining tool at the corresponding machining point, the flexible machining tool is controlled to adaptively eliminate the removal differences of anisotropic thin-walled curved workpieces under different machining postures and machining crystal surfaces, thereby achieving high-precision controllable grinding and polishing.

2. The time-space controlled grinding and polishing method for anisotropic thin-walled curved workpieces according to claim 1, characterized in that: It includes the following steps: S1: Detect and obtain the initial surface shape, crystal plane orientation and crystal direction orientation of the anisotropic thin-walled curved surface workpiece, fix the anisotropic thin-walled curved surface workpiece on a multi-axis parallel motion platform, select the processing posture of the flexible processing tool at each processing point based on the crystal direction orientation of the anisotropic thin-walled curved surface workpiece, and make the processing linear velocity direction of the flexible processing tool consistent with the crystal direction of the processing point position of the anisotropic thin-walled curved surface workpiece; S2: Based on the contact pressure field distribution of the flexible machining tool in the target machining area and the machining crystal surface, the spatial displacement control amount required after the flexible machining tool and the anisotropic thin-walled curved surface workpiece are deformed at each machining point is calculated; S3: setting the target surface shape result, determining the target material removal volume based on the initial surface shape and the target surface shape, and calculating the material removal rate when the flexible machining tool removes material from the machining crystal surface under the machining posture in combination with the contact pressure field and the machining parameters; S4: Calculate the residence time of the flexible machining tool at each machining point in the full-area grinding and polishing by deconvolution based on the target material removal volume and material removal rate; S5: The flexible machining tool is driven according to the spatial displacement control amount and the dwell time of the flexible machining tool at each machining point, and then the anisotropic thin-walled curved surface workpiece is subjected to full-area grinding and polishing.

3. The time-space controlled grinding and polishing method for anisotropic thin-walled curved workpieces according to claim 2, characterized in that: In S1, the anisotropic thin-walled curved workpiece is fixed on the multi-axis parallel motion platform by only constraining the boundaries. The only constraining boundaries fixation method means that there is no support in the middle, and the edges are fixed, simply supported, conditional boundaries or free clamping boundaries.

4. The time-space controlled polishing method for anisotropic thin-walled curved workpiece according to claim 2, characterized in that: The displacement control amount of the flexible processing tool in S2 in the spatial domain The calculation formula is: (1)， (2)， (3)， in, is the equivalent Young's modulus of the anisotropic thin-walled curved workpiece when the flexible machining tool removes material on the corresponding machining crystal surface. is the tool Poisson’s ratio, and are the distance and azimuth between the calculation point and the pressure position, respectively. is the equivalent radius of the flexible machining tool, Indicates the distance between the point in the pressure area and the processing point The distance is the pressure distribution at the processing point, The displacement control amount of the flexible machining tool is set to ensure a uniform pressure field distribution by considering the deformation of the workpiece and the tool. For processing point The deformation of the flexible processing tool, is the maximum deformation of the flexible processing tool, It is the deformation of the anisotropic thin-walled curved workpiece at the maximum deformation position of the flexible machining tool.

5. The time-space controlled polishing method for anisotropic thin-walled curved workpiece according to claim 4, characterized in that: The material removal rate calculation formula of the flexible machining tool in S3 is: (4)， (5)， (6)， in, is the yield limit of the processed crystal direction, It is the material removal rate of a single abrasive grain on the machined crystal surface. It is the penetration depth of a single abrasive grain on the machined crystal surface to remove material. is the flexible machining tool speed, is the material removal rate of all abrasive particles at the processing point, is the number of abrasive particles, To set the radius of the abrasive particles.

6. The time-space controlled polishing method for anisotropic thin-walled curved workpiece according to claim 5, characterized in that: The residence time of the flexible processing tool in the full-area grinding and polishing in S4 at each processing point that needs to be regulated in the time domain The calculation formula is: (7)， in, For processing point The processing time at For processing point The target removal volume at is the deconvolution calculation symbol, For processing point The pressure exerted on the abrasive particles at the 7. The time-space controlled polishing method for anisotropic thin-walled curved workpiece according to claim 4, characterized in that: In S2, the maximum deformation of the flexible processing tool is set to be less than 20% of the thickness of the processed workpiece.

8. The time-space controlled polishing method for anisotropic thin-walled curved workpiece according to claim 4, characterized in that: In the S2, it is set that the pressure exerted by the flexible processing tool on the anisotropic thin-walled curved surface workpiece is not greater than 3 times the yield stress limit of the flexible processing tool and the processing crystal surface material under the selected processing posture.

9. A time-space controlled grinding and polishing device for anisotropic thin-walled curved workpieces, characterized in that: It includes a multi-axis parallel motion platform, a controller, a calculator and a flexible processing tool; The multi-axis parallel motion platform is used to fix anisotropic thin-walled curved surface workpieces and flexible processing tools; The calculator calculates the spatial displacement control amount and material removal rate of the flexible machining tool at each machining point based on the machining posture of the flexible machining tool at each machining point and the machining crystal surface of the anisotropic thin-walled curved workpiece, calculates the residence time of the flexible machining tool at the corresponding machining point based on the material removal rate and the target removal volume of the corresponding machining point by deconvolution, and transmits the calculated spatial displacement control amount and residence time to the controller; The controller is used to drive the multi-axis parallel motion platform based on the spatial displacement control amount and dwell time of the flexible processing tool at the corresponding processing point, so that the linear velocity direction of the processing of the flexible processing tool is consistent with the crystal direction of the processing point position of the anisotropic thin-walled curved surface workpiece. At the same time, the flexible processing tool is controlled to adaptively eliminate the removal difference of the anisotropic thin-walled curved surface workpiece under different processing postures and processing crystal planes, thereby realizing high-precision controllable grinding and polishing.

10. The time-space controlled polishing device for anisotropic thin-walled curved workpieces according to claim 9, characterized in that: The multi-axis parallel motion platform includes a base, an X-axis motion platform, a Y-axis motion platform, a fixed tool, a frame, a crossbeam, a Z-axis motion platform, and a rotating axis. The flexible processing tool is fixed on the rotating axis and is used to grind and polish anisotropic thin-walled curved surface workpieces; the X-axis motion platform is connected above the base, the Y-axis motion platform is connected above the X-axis motion platform, the X-axis motion platform and the Y-axis motion platform are perpendicular to each other, the fixed tool is installed on the Y-axis motion platform, the fixed tool is used to fix the anisotropic thin-walled curved surface workpiece, and the anisotropic thin-walled curved surface workpiece is linked in the X-axis direction and the Y-axis direction through the X-axis motion platform and the Y-axis motion platform, the crossbeam is installed on the base through the frame, the rotating axis is installed on the crossbeam, the Z-axis motion platform is installed on the rotating axis, the flexible processing tool is installed on the Z-axis motion platform, and the adjustment of the flexible processing tool on the Z-axis and the adjustment of the processing angle are respectively realized through the Z-axis motion platform and the rotating axis.

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