Ultra-precision time-controlled grinding method and system for planar mechanical parts

Abstract

The present invention discloses a method and system for ultra-precision time-controlled grinding of planar mechanical parts. The method comprises: measuring the surface shape data of the current plane of a workpiece using a non-contact profilometer, calculating error data of the current plane based on the surface shape data, and setting time-controlled grinding parameters based on the error data; processing a sample using a time-controlled grinding machine under the time-controlled grinding parameters to obtain a removal function, and performing time-controlled grinding and shaping of the current plane based on the error data and the removal function using a one-dimensional convolution algorithm; measuring the surface shape data of the current plane after processing using a non-contact profilometer, and calculating error data of the current plane based on the surface shape data. If the error data accuracy does not meet the standard, executing the step of measuring the error data of the current plane of the workpiece using the non-contact profilometer until the measurement accuracy meets the standard. The present invention can process planar mechanical parts with high efficiency and high shape and position accuracy.

Description

Technical Field

[0001] The present invention relates to the field of ultra-precision machining of mechanical parts, and in particular to an ultra-precision time-controlled grinding method and system for planar mechanical parts. Background Art

[0002] Flat mechanical parts are widely used in the machinery industry, including components such as valves, adjustment platforms, and turntables. Spacers and thrust bearings in ultra-precision hydrostatic spindles and turntables require extremely high-precision flat surfaces to ensure accurate rotation. For example, thrust bearing spacers in ultra-precision hydrostatic shafting systems are currently mostly made of alloy steel with a flat, circular ring structure and high mechanical strength. These parts must achieve submicron flatness and micron-level parallelism on surfaces with a diameter of 150-200 mm. Due to the limitations of single-point diamond ultra-precision turning, these parts are often processed using ultra-precision surface grinders. Traditional ultra-precision grinding machines adhere to the "maternal principle" and are limited by factors such as machine tool motion accuracy and clamping deformation. Further improvements in grinding accuracy are extremely difficult, and the economical machining accuracy of existing ultra-precision surface grinders remains at 1-2 microns for flatness and 2-3 microns for parallelism. At present, subsequent precision improvements often rely on technicians to use measurement data and perform manual grinding. This is inefficient and highly dependent on the technicians' operating experience, which is not conducive to the automated and high-precision production of high-precision planar mechanical parts.

[0003] Time-controlled grinding technology is based on CCOS technology. Through the computer, the grinding head precisely controls the quantitative removal of each position on the workpiece surface, removing more points with high errors and less points with low errors, thereby achieving convergence with sub-micron precision. The non-contact profilometer solves the problems of insufficient measurement accuracy of traditional three-dimensional coordinate machines, insufficient measurement and leveling accuracy of cylindricity meters, and inability of laser interferometers to form images, providing high-precision measurement data guarantee for high-precision time-controlled grinding of mechanical parts.

[0004] How to apply the high-precision machining of time-controlled grinding technology and the high-precision measurement of non-contact profilometers to the machining of planar mechanical parts is a topic worthy of study. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to design a new method for processing planar mechanical parts, which can realize high-efficiency automatic processing of workpieces with submicron flatness and micron-level parallelism.

[0006] In view of the technical problems existing in the prior art, the present invention provides an ultra-precision time-controlled grinding method and system for planar mechanical parts, which can perform high-efficiency and high-precision machining.

[0007] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0008] An ultra-precision time-controlled grinding method for planar mechanical parts comprises the following steps:

[0009] S1) measuring the surface shape data of the current plane of the workpiece with a non-contact profilometer, calculating error data of the current plane based on the surface shape data, and setting time-controlled grinding parameters based on the error data;

[0010] S2) processing the sample with a time-controlled grinding machine under the time-controlled grinding parameters to obtain a removal function, and performing time-controlled grinding and shaping of the current plane according to the error data of the current plane and the removal function using a one-dimensional convolution algorithm;

[0011] S3) Using a non-contact profilometer to measure the surface data of the processed current plane, and calculating the error data of the current plane based on the surface data, if the error data accuracy does not meet the standard, return to step S1 until the measurement accuracy meets the standard, if the error data accuracy meets the standard, the current plane is processed.

[0012] Furthermore, the workpiece is a circular planar workpiece including a surface A and a surface B. When the current plane is surface A, step S1 specifically includes the following steps:

[0013] Place surface A upward, control the probe of the non-contact profilometer to move in a circular trajectory, and obtain the surface shape data of surface A;

[0014] The surface shape data of surface A is de-tilted and filtered to obtain the flatness error of surface A. If the flatness error of surface A is greater than the preset threshold, the time-controlled grinding parameters with high removal efficiency are selected. If the flatness error of surface A is less than the preset threshold, the time-controlled grinding parameters with low removal efficiency are selected.

[0015] Furthermore, when the current plane is plane B, step S1 specifically includes:

[0016] Place surface A downward and in contact with the reference plane of the reference flat crystal, control the probe of the non-contact profilometer to move in a circular trajectory and obtain the surface shape data SB(ρ,θ) of surface B;

[0017] Control the probe of the non-contact profilometer to move to the inside of the circular contour of the metal circular planar part, measure the reference plane of the reference flat crystal, and reconstruct the tilted plane SBt(ρ,θ) based on the measurement results;

[0018] The surface shape data SB(ρ,θ) is filtered and then subtracted from the inclined plane SBt(ρ,θ) to obtain the error data of the B surface.

[0019] Furthermore, the flatness of the reference plane of the reference flat crystal is λ / 100RMS, where λ=632.8 nm.

[0020] Furthermore, in step S2, the step of using a one-dimensional convolution algorithm to perform time-controlled grinding and shaping on the current plane according to the error data of the current plane and the removal function specifically includes:

[0021] Select the target contour on the surface data of the current plane, calculate the average value of the error distribution of the target contour, and obtain the measured contour;

[0022] Selecting a target removal function profile on the removal function, calculating an average value of the target removal function profile, and obtaining a one-dimensional profile of the removal function;

[0023] Use the dwell time calculation algorithm, input the one-dimensional profile of the removal function and the measured profile, perform a one-dimensional convolution operation, solve the dwell time distribution of each position on the current plane, and generate the processing code;

[0024] Fix the workpiece on the time-controlled grinding machine, input the processing code into the time-controlled grinding machine, and perform the shaping process.

[0025] Furthermore, the specific steps of fixing the workpiece on the time-controlled grinding machine include: fixing the processing head position of the time-controlled grinding machine, concentrically arranging the workpiece and the C-axis turntable of the time-controlled grinding machine, and then fixing the workpiece on the C-axis turntable.

[0026] Furthermore, the step of measuring the surface shape data of the processed current plane using a non-contact profilometer in step S3 and calculating the error data of the current plane based on the surface shape data specifically includes:

[0027] With the current plane facing upward, the probe of the non-contact profilometer is controlled to move in a circular trajectory and obtain the surface shape data of the current plane;

[0028] The surface data of the current plane is de-tilted and filtered to obtain the flatness error of the current plane. If the flatness error of the current plane is less than or equal to the target accuracy, the error data accuracy meets the standard.

[0029] Furthermore, the target accuracy is 1 μm.

[0030] The present invention also provides an ultra-precision time-controlled grinding processing system for planar mechanical parts, comprising a computer, wherein the computer is programmed or configured to execute any of the ultra-precision time-controlled grinding processing methods for planar mechanical parts.

[0031] The present invention also provides a computer-readable storage medium, which stores a computer program programmed or configured to execute any of the aforementioned ultra-precision time-controlled grinding methods for planar mechanical parts.

[0032] Compared with the prior art, the advantages of the present invention are:

[0033] Before processing each side of a planar mechanical part, the present invention uses a non-contact profile measuring instrument to measure error data, then sets corresponding time-controlled grinding processing parameters based on the error data, and uses a one-dimensional convolution algorithm to perform time-controlled grinding and shaping in combination with the structural characteristics of the metal circular planar part, thereby reducing the edge effect problem in the current two-dimensional convolution process used in time-controlled grinding and shaping; and considering that both the flatness error of the B side of the planar mechanical part and the parallelism error of the B side relative to the A side need to be controlled, when measuring the B side with a non-contact profile measuring instrument, a reference flat crystal is also used to measure the parallelism, thereby providing accurate data basis for high-precision processing of the B side. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of processing annular planar parts in an embodiment of the present invention.

[0035] Figure 2 Schematic diagram of the measurement trajectory of the annular planar workpiece in an embodiment of the present invention.

[0036] Figure 3 Schematic diagram of the extraction and processing of single plane surface data of an annular planar workpiece in an embodiment of the present invention.

[0037] Figure 4 Schematic diagram of the extraction and processing of the time-controlled grinding removal function for a circular planar workpiece in an embodiment of the present invention.

[0038] Figure 5 Schematic diagram of the time-controlled grinding process of a single plane of an annular planar workpiece in an embodiment of the present invention.

[0039] Figure 6 Schematic diagram of the reference plane measurement of the parallelism of the annular planar workpiece in an embodiment of the present invention.

[0040] Figure 7 Schematic diagram of the oblique plane reconstruction of the annular planar workpiece reference flat crystal in an embodiment of the present invention.

[0041] Figure 8 Schematic diagram of parallelism error data extraction and processing of annular planar workpieces in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby.

[0043] To apply the high-precision machining of time-controlled grinding technology and the high-precision measurement of non-contact profilometers to the machining of planar mechanical parts, we propose an ultra-precision time-controlled grinding method for planar mechanical parts. The machining of each side includes the following steps:

[0044] S1) measuring the surface shape data of the current plane of the workpiece with a non-contact profilometer, calculating error data of the current plane based on the surface shape data, and setting time-controlled grinding parameters based on the error data;

[0045] S2) processing the sample with a time-controlled grinding machine under the time-controlled grinding parameters to obtain a removal function, and performing time-controlled grinding and shaping of the current plane according to the error data of the current plane and the removal function using a one-dimensional convolution algorithm;

[0046] S3) Using a non-contact profilometer to measure the surface data of the processed current plane, and calculating the error data of the current plane based on the surface data, if the error data accuracy does not meet the standard, return to step S1 until the measurement accuracy meets the standard, if the error data accuracy meets the standard, the current plane is processed.

[0047] In the above steps, when using a non-contact profilometer to measure the surface shape data of the current plane of the workpiece, for the first processed plane, only the flatness error needs to be calculated. For the subsequently processed plane, the error data includes not only its own flatness error but also the parallelism error between it and the first processed plane. The common scenario of non-contact profilometers is to measure the surface topography error of a single plane / sphere / aspheric surface, and is not used to measure parallelism. We consider using a non-contact profilometer with a reference flat crystal to measure flatness and parallelism, which solves the problems of insufficient measurement accuracy of traditional three-dimensional coordinate machines, insufficient leveling accuracy of cylindricity meters, and inability of laser interferometers to form images, providing high-precision measurement data guarantee for high-precision time-controlled grinding of mechanical parts.

[0048] Furthermore, given the large aspect ratio of planar mechanical parts, surface shape errors are primarily distributed along the planar direction, while radial error gradients are relatively small. Therefore, the error distribution across the entire plane can be roughly considered as the error distribution along a single contour. Therefore, based on the time-controlled grinding method, we employed a one-dimensional convolution algorithm for time-controlled grinding and shape correction, mitigating the edge effects that currently exist in two-dimensional convolution processes used in time-controlled grinding and shape correction.

[0049] The following takes the processing of annular planar workpieces as an example to specifically explain the ultra-precision time-controlled grinding method for planar mechanical parts.

[0050] For a circular plane workpiece, it includes surface A and surface B, where surface A is the first processed plane and surface B is the reverse side of surface A. Figure 1 As shown, the processing of annular planar workpieces using the ultra-precision time-controlled grinding method of planar mechanical parts includes the following steps:

[0051] 1) Use a non-contact profilometer to measure the flatness error data of surface A, pre-process the flatness error data, select appropriate time-controlled grinding parameters to configure a time-controlled grinding machine to process the sample;

[0052] 2) Calculate the one-dimensional profile of the removal function and the measured profile of surface A, and use the one-dimensional convolution algorithm to perform grinding and shaping of surface A during flatness control;

[0053] 3) Use a non-contact profilometer to measure the processed A surface to obtain new flatness error data. If the measurement accuracy of the flatness error data does not meet the standard, return to step 1); if the accuracy meets the standard, proceed to step 4);

[0054] 4) Use a non-contact profilometer and a reference flat crystal to measure surface B to obtain the flatness of surface B and the parallelism error data of surface B relative to surface A. After pre-processing the data, select appropriate time-controlled grinding parameters to configure the time-controlled grinding machine to process the sample;

[0055] 5) Calculate the one-dimensional profile of the removal function and the measured profile of the B surface, and use the one-dimensional convolution algorithm to perform grinding and shaping of the B surface during flatness control;

[0056] 6) Use a non-contact profilometer to measure the processed B surface to obtain new flatness error data. If the measurement accuracy of the flatness error data does not meet the standard, return to step 4). If the processing result accuracy meets the standard, the processing is completed.

[0057] In this embodiment, step 1) is the specific steps of step S1 described above when the current plane is plane A, and includes the following steps:

[0058] 1.1) Place the workpiece on the workpiece table of the non-contact profilometer with surface A facing upwards. Control the probe of the non-contact profilometer to move in a circular trajectory and obtain the surface shape data of surface A.

[0059] In this embodiment, since the form and position tolerances of the processed parts reach the submicron level, and the measurement accuracy of the commonly used three-dimensional coordinate measuring machine can only reach the 1μm level, it is impossible to accurately obtain the surface data of the workpiece; the cylindricity meter can be used to measure the flatness of the spacer ring, but the surface of the circular workpiece has many holes, and the probe will mechanically interfere with them. In addition, the leveling accuracy of the cylindricity meter (0.5μm) has a significant impact on the parallelism measurement of the circular workpiece; the wavefront interferometer can achieve subnanometer plane measurement accuracy, but it has high requirements for the size, surface roughness, and surface steepness of the workpiece. The surface roughness after grinding is large, and the interferometer cannot obtain sufficient reflected signal. Therefore, the wavefront interferometer is not suitable for surface measurement of mechanical parts after grinding. The non-contact profilometer uses a spectral confocal displacement probe, which has good adaptability to the roughness of the part surface. The linear motion axis of the entire measuring device is driven by an air-bearing guide rail. The overall plane measurement accuracy of the device is approximately 100nm, which meets the processing requirements of submicron mechanical parts.

[0060] In this embodiment, Figure 2 As shown in the figure, the probe axis of the non-contact profilometer is orthogonal to the workpiece surface, and the probe trajectory is a circle of concentric circles. Under the control of the CNC system, the non-contact profilometer completes the movement of the above concentric circle trajectory relative to the workpiece, and at the same time collects the measurement data of the probe. After that, the surface error data on the concentric circle contour can be fitted into a circular plane.

[0061] 1.2) De-tilting and filtering the surface shape data of surface A to obtain the flatness error of surface A. If the flatness error of surface A is greater than a preset threshold, a time-controlled grinding parameter with high removal efficiency is selected. If the flatness error of surface A is less than the preset threshold, a time-controlled grinding parameter with low removal efficiency is selected.

[0062] In this embodiment, due to the non-parallelism between the workpiece's A and B surfaces, and the fact that the workpiece platform tilts after placement, the raw data measured by the probe contains the flatness of surface A itself and a tilt component. Therefore, the measured data needs to be de-tilted to obtain the flatness error distribution of workpiece surface A. Furthermore, since the measurement process is a line scan process, some high-frequency noise is coupled into the measurement process. Therefore, a low-pass filtering method can be used to filter out high-frequency system noise and retain valid surface error data. It should be noted that de-tilting and filtering are conventional methods well known to those skilled in the art, and this solution does not involve improvements in their implementation, so the specific operation process will not be described in detail here.

[0063] Step 2) of this embodiment, i.e., when the current plane is plane A, the specific steps of using the one-dimensional convolution algorithm in step S2 described above to perform time-controlled grinding and shaping of the current plane according to the error data of the current plane and the removal function, specifically include:

[0064] 2.1) Select the target contour on the surface data of the current plane, calculate the average value of the error distribution of the target contour, and obtain the measured contour;

[0065] In this embodiment, Figure 3 As shown, since the workpiece has a relatively large length (circumferential direction) and width (annular width), the surface error distribution is mainly along the circumferential direction, while the radial error gradient of the annulus is relatively small. Therefore, the error distribution on the entire annular surface can be approximately regarded as the error distribution on a single circular contour. Averaging multiple contour data can reduce the impact of accidental errors and improve the reliability of error sampling. Therefore, in this step, 2-3 circular contours are selected from the surface data of surface A generated in step 1), and the error distribution on each contour is extracted. The data on these contours are averaged to obtain the contour error distribution to be corrected, i.e., the measured contour.

[0066] 2.2) Obtaining a removal function, selecting a target removal function profile on the removal function, calculating an average of the target removal function profile, and obtaining a one-dimensional profile of the removal function;

[0067] In this embodiment, the removal function is obtained by processing a sample with the same size as the workpiece on a time-controlled grinding machine under the time-controlled grinding parameter configuration. When the current plane is surface A, the removal function is obtained by processing surface A of the sample. When the current plane is surface B, the removal function is obtained by processing surface B of the sample. The morphology of the removal function is as follows: Figure 4 As shown, the main shape of the removal function is distributed in the circumferential direction, and the contours of the removal function in the radial direction are basically the same. Therefore, the removal function can also be represented by extracting the one-dimensional contour of the removal function in the circumferential direction as in step 2.1);

[0068] 2.3) Using the dwell time calculation algorithm, input the one-dimensional profile of the removal function and the measured profile, perform a one-dimensional convolution operation, solve the dwell time distribution of each position on the current plane, and generate the processing code;

[0069] In this embodiment, as described in 2.1), the workpiece error distribution is approximated as a contour in the circumferential direction. As described in 2.2), the contour of the removal function along the circumferential direction is basically the same, and is also approximated as a contour in the circumferential direction. Therefore, the shaping of the entire annular part becomes a process of convolution solution of a one-dimensional removal function and a one-dimensional dwell time. Compared with the traditional two-dimensional convolution solution, the dwell time solution and processing efficiency of this processing method are higher, and there is no edge effect. Therefore, it is suitable for the processing of annular planar parts.

[0070] 2.4) Fix the workpiece on the time-controlled grinding machine, input the processing code into the time-controlled grinding machine, and perform the shaping process.

[0071] In this embodiment, in order to realize the time-controlled grinding and shaping of the annular surface, the workpiece is fixed on the time-controlled grinding machine. Figure 5 As shown, the position of the machining head of the time-controlled grinding machine is fixed, and the center of the circular workpiece and the C-axis turntable of the time-controlled grinding machine are set concentrically by dialing, and then the workpiece is fixed on the C-axis turntable to realize the circular motion of the time-controlled grinding head relative to the workpiece, thereby achieving quantitative removal of each position on the workpiece surface.

[0072] Step 3) in this embodiment is the specific steps of step S3 described above when the current plane is plane A, wherein the steps of measuring the error data of the current plane, i.e., plane A, are substantially the same as step 1), and specifically include:

[0073] Similar to step 1), the current plane is turned upward, and the probe of the non-contact profilometer is controlled to move in a circular trajectory to obtain the surface data of the current plane;

[0074] The surface data of the current plane is de-tilted and filtered to obtain the flatness error of the current plane. If the flatness error of the current plane is less than or equal to the target accuracy, the error data accuracy meets the standard.

[0075] In step 3), if the error data accuracy meets the target, proceed to step 4), otherwise return to step 1) for iterative processing. In this embodiment, the target accuracy is 1 μm, and the value of the target accuracy can be adjusted according to actual conditions.

[0076] Step 4) of this embodiment is the specific steps of step S1 described above when the current plane is plane B, and includes the following steps:

[0077] 4.1) Place a high-precision reference flat crystal on the workpiece table of a non-contact profilometer with the reference plane facing upward. Then, place surface A facing downward and contacting the reference plane of the reference flat crystal. Control the probe of the non-contact profilometer to move in a circular trajectory and obtain the surface shape data SB(ρ,θ) of surface B. This data only needs to be filtered and no de-tilting is performed.

[0078] In this embodiment, the flatness of the reference plane of the reference flat crystal is λ / 100RMS, λ = 632.8nm, and it can be considered a surface with no flatness error. In this step, the reference flat crystal is placed on the workpiece platform of the non-contact profilometer with the reference plane facing upward. At this time, the A surface of the workpiece is a well-processed surface, so the newly processed A surface is placed downward in contact with the reference plane of the flat crystal. The B surface is facing upward, which is the side to be measured. The measured raw data SB(ρ,θ) can be expressed as follows:

[0079] SB(ρ,θ)=SBc(ρ,θ)+SBt(ρ,θ)+Sp(ρ,θ) (1)

[0080] Where SBc(ρ,θ) is the least squares flatness error of the ring workpiece B surface itself, SBt(ρ,θ) is the measurement error caused by the tilted placement of the ring workpiece, and Sp(ρ,θ) is the parallelism error distribution of the B surface relative to the A surface (reference flat crystal reference plane), as shown in Figure 8 As shown;

[0081] 4.2) Control the probe of the non-contact profilometer to move to the inside of the circular contour of the metal circular planar part, measure the reference plane of the reference flat crystal, and reconstruct the tilted plane SBt(ρ,θ) based on the measurement results;

[0082] In this embodiment, Figure 6 As shown, the annular plane workpiece is a hollow structure. When the position coordinates of the probe in the horizontal plane are located inside the ring, there is no object blocking the probe and the reference flat crystal, and the surface of the reference flat crystal can be directly measured to obtain the surface data of the reference plane. Due to installation errors, parallelism errors between the two planes of the reference flat crystal, etc., the reference plane of the reference flat crystal has a certain inclination relative to the absolute plane. In order to accurately evaluate the parallelism error later, the inclination needs to be separated and eliminated. The surface data of the reference plane can be fitted into an ideal inclined plane by least squares. An ideal inclined plane SBt(ρ,θ) with a size comparable to that of the annular plane workpiece can be obtained by geometric scaling, as shown in Figure 7 shown.

[0083] 4.3) After filtering the surface data SB(ρ,θ), the surface data is subtracted from the tilted plane SBt(ρ,θ) to obtain the error data of surface B. The error distribution to be corrected for surface B of the workpiece is obtained by subtracting the reconstructed tilted plane SBt(ρ,θ) from the unde-tilted data SB(ρ,θ). This error distribution includes the least squares flatness error of the workpiece itself and the parallelism error of surface B relative to surface A. Both errors need to be controlled.

[0084] In step 4) of this embodiment, after obtaining the error data of surface B, the error data of surface B is also compared with the preset threshold. If the error data of surface B is greater than the preset threshold, the time-controlled grinding parameters with high removal efficiency are selected. If the error data of surface B is less than the preset threshold, the time-controlled grinding parameters with low removal efficiency are selected.

[0085] Step 5) of this embodiment is the specific step of using the one-dimensional convolution algorithm in step S2 described above to perform time-controlled grinding and shaping on the current plane according to the error data and removal function of the current plane when the current plane is surface B. The specific steps are the same as step 2) and will not be repeated here.

[0086] Step 6) of this embodiment is the specific step of step S3 mentioned above when the current plane is surface B, wherein the specific step of measuring the error data of the current plane, i.e., surface B, is the same as step 3) and will not be repeated here. If the accuracy of the error data meets the standard, the processing process is completed, otherwise it returns to step 4) for iterative processing.

[0087] This embodiment also provides an ultra-precision time-controlled grinding processing system for planar mechanical parts, including a computer, wherein the computer is programmed or configured to execute the ultra-precision time-controlled grinding processing method for planar mechanical parts described in this embodiment.

[0088] This embodiment further provides a computer-readable storage medium, which stores a computer program programmed or configured to execute the ultra-precision time-controlled grinding method for planar mechanical parts described in this embodiment.

[0089] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed above with reference to the preferred embodiment, it is not intended to limit the present invention. Therefore, any simple modifications, equivalent variations, and modifications to the above embodiment that do not depart from the technical solution of the present invention and are based on the technical essence of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for ultra-precision time-controlled grinding of planar mechanical parts, characterized in that: The following steps are involved: S1) measuring the surface shape data of a current plane of a workpiece using a non-contact profilometer, calculating error data of the current plane based on the surface shape data, and setting time-controlled grinding parameters based on the error data, wherein the workpiece is a circular planar workpiece including a first processed surface A and a subsequently processed surface B, and when the current plane is surface B, measuring the surface shape data of the current plane of the workpiece using a non-contact profilometer, and calculating the error data of the current plane based on the surface shape data, specifically comprises the following steps: Place the reference flat crystal on the workpiece table of the non-contact profilometer with the reference plane facing upward, and place surface A facing downward and in contact with the reference plane of the reference flat crystal. Control the probe of the non-contact profilometer to move in a circular trajectory and obtain the surface shape data SB(ρ,θ) of surface B; Control the probe of the non-contact profilometer to move to the inside of the circular contour of the metal circular planar part, measure the reference plane of the reference flat crystal, and reconstruct the tilted plane SBt(ρ,θ) based on the measurement results; After filtering, the surface shape data SB(ρ,θ) is subtracted from the tilted plane SBt(ρ,θ) to obtain the error data of surface B. S2) processing the sample with a time-controlled grinding machine under the time-controlled grinding parameters to obtain a removal function, and performing time-controlled grinding and shaping of the current plane according to the error data of the current plane and the removal function using a one-dimensional convolution algorithm; S3) Using a non-contact profilometer to measure the surface data of the processed current plane, and calculating the error data of the current plane based on the surface data, if the error data accuracy does not meet the standard, return to step S1 until the measurement accuracy meets the standard, if the error data accuracy meets the standard, the current plane is processed.

2. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 1, characterized in that: When the current plane is plane A, the specific steps of step S1 include: Place surface A upward, control the probe of the non-contact profilometer to move in a circular trajectory, and obtain the surface shape data of surface A; The surface shape data of surface A is de-tilted and filtered to obtain the flatness error of surface A. If the flatness error of surface A is greater than the preset threshold, the time-controlled grinding parameters with high removal efficiency are selected. If the flatness error of surface A is less than the preset threshold, the time-controlled grinding parameters with low removal efficiency are selected.

3. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 1, characterized in that: The flatness of the reference plane of the reference flat crystal is λ / 100 RMS, where λ=632.8 nm.

4. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 1, characterized in that: In step S2, the steps of using a one-dimensional convolution algorithm to perform time-controlled grinding and shaping of the current plane according to the error data and removal function of the current plane specifically include: Select the target contour on the surface data of the current plane, calculate the average value of the error distribution of the target contour, and obtain the measured contour; Selecting a target removal function profile on the removal function, calculating an average value of the target removal function profile, and obtaining a one-dimensional profile of the removal function; Use the dwell time calculation algorithm, input the one-dimensional profile of the removal function and the measured profile, perform a one-dimensional convolution operation, solve the dwell time distribution of each position on the current plane, and generate the processing code; Fix the workpiece on the time-controlled grinding machine, input the processing code into the time-controlled grinding machine, and perform the shaping process.

5. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 4, characterized in that: The specific steps of fixing the workpiece on the time-controlled grinding machine include: fixing the processing head position of the time-controlled grinding machine, setting the workpiece and the C-axis turntable of the time-controlled grinding machine concentrically, and then fixing the workpiece on the C-axis turntable.

6. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 1, characterized in that: The step of measuring the surface shape data of the processed current plane using a non-contact profilometer in step S3 and calculating the error data of the current plane based on the surface shape data specifically includes: With the current plane facing upward, the probe of the non-contact profilometer is controlled to move in a circular trajectory and obtain the surface shape data of the current plane; The surface data of the current plane is de-tilted and filtered to obtain the flatness error of the current plane. If the flatness error of the current plane is less than or equal to the target accuracy, the error data accuracy meets the standard.

7. The ultra-precision time-controlled grinding method for planar mechanical parts according to claim 6, characterized in that: The target accuracy is 1 μm.

8. An ultra-precision time-controlled grinding system for planar mechanical parts, characterized in that: The method comprises a computer, wherein the computer is programmed or configured to execute the ultra-precision time-controlled grinding method for planar mechanical parts according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that The storage medium stores a computer program programmed or configured to execute the ultra-precision time-controlled grinding method for planar mechanical parts according to any one of claims 1 to 7.

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