Machine tool spindle rotation error measurement method based on installation error correction

Abstract

The invention provides a machine tool spindle rotation error measurement method based on installation error correction, and the method comprises the steps: fixedly installing a high-precision plane mirror at the central position of the bottom of a spindle cutterhead through a bolt, and fixedly installing a laser interferometer below the high-precision plane mirror; before measurement, corresponding relation data of different installation error values and residual synchronization errors caused by the installation error values are quantitatively calculated; then, calculating an installation error control range required for enabling the residual synchronization error caused by the installation error to be within the required measurement precision; during detection, the installation error of the measuring device is obtained; adjusting the installation error by adjusting the installation position of the laser interferometer until the maximum amplitude (namely the installation error) of the basic synchronous rotation error extracted from the measurement data reaches the required installation error range; and after the installation error adjustment of the measuring device is completed, data acquisition is carried out to obtain the total axial rotation error data of the main shaft, and the axial synchronous and asynchronous rotation errors of the main shaft are calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-precision machine tool spindle rotation error measurement, and in particular to a machine tool spindle rotation error measurement method based on installation error correction. Background Art

[0002] As a core component of machine tools, the spindle's rotational error is a crucial indicator of machine tool performance and precision. According to the American Society of Mechanical Engineers (ASME) standard, spindle rotational error can be classified based on frequency into synchronous error and asynchronous error. Synchronous error, also known as average error, refers to the sum of components whose frequencies are integer multiples of the spindle's rotational frequency. Asynchronous error, also known as random error, refers to the sum of components whose frequencies are non-integer multiples of the spindle's rotational frequency. This classification is of practical significance for engineering evaluation and tracing the source of spindle rotational error. Synchronous error recurs in the same pattern with each rotation, making it easy to predict and compensate for. Synchronous rotational error is further divided into fundamental error and residual error. Fundamental error refers to the component that rotates synchronously with the spindle speed, namely the first harmonic. Residual error refers to the synchronous error component beyond the fundamental error, namely the second, third, and higher-order harmonics. Asynchronous error, on the other hand, is generally considered random and difficult to predict and compensate. Synchronous error often corresponds to periodic, low-frequency ripple errors in the machined surface, while asynchronous error more often causes high-frequency surface roughness errors. In vertical ultra-precision fly-cutting machines, the axial direction is a sensitive machining direction, significantly impacting workpiece quality. Therefore, high-precision measurement of the synchronous and asynchronous axial rotation errors of the spindle is required to monitor machine accuracy and workpiece quality.

[0003] The traditional spindle rotation error measurement method is limited by the accuracy of the detection means used and the accuracy of the standard measured parts, and cannot be used for the detection of nanometer-level precision spindle rotation errors. In addition, some high-precision detection methods are not suitable for the measurement of high-speed rotating spindle rotation errors due to their limited response frequency. Moreover, among the existing spindle rotation error detection methods, most only measure the total spindle rotation error, and do not separate the spindle synchronous rotation error and asynchronous rotation error, which limits the tracing of the spindle rotation error and the further improvement of the rotation accuracy. In the measurement method of the axial asynchronous rotation error of the spindle of a vertical ultra-precision fly-cutting machine tool by An et al., a capacitive displacement sensor is used to measure the motion trajectory of the standard ball installed on the top of the spindle as the spindle rotates, thereby obtaining the axial synchronous and asynchronous rotation errors of the spindle. However, there are the following deficiencies in this method, which will lead to certain measurement errors: (1) Since the standard ball to be measured is installed on the top of the spindle, away from the cutter head end of the spindle, the tilt motion error of the spindle will be transmitted to the measurement data of the spindle axial rotation error. The measured axial rotation error data will have a certain deviation from the actual axial motion trajectory of the spindle tool.

[0004] (2) Since the object to be measured is a high-precision standard sphere, the shape error of the standard sphere will be transmitted to the measurement result, and the radial rotation error of the spindle will also be transmitted to the measurement data of the axial rotation error through the radial runout of the standard sphere, introducing a certain measurement error.

[0005] Moreover, existing measurement methods generally assume that there is no installation error in the measuring device, or that the measurement error caused by the installation error of the measuring device can be ignored. For example, in the measurement of the spindle axial error, a conic mirror or a reference object is horizontally installed at the end of the spindle to measure the spindle axial error. However, in the actual measurement process, a certain installation error will inevitably be generated, and the installed reference object will have a small angle of inclination. When the rotation error of the spindle is in the micron or millimeter level, the measurement error caused by the installation error can be ignored. However, for ultra-precision spindles, when the rotation error of the spindle is in the nanometer level, the measurement error caused by the installation error cannot be ignored. Therefore, there is an urgent need to quantitatively calculate the measurement error caused by the installation error of the measuring device in the measurement of the axial synchronous and asynchronous rotation error of the spindle of a vertical ultra-precision machine tool, and to correct and regulate it, so as to achieve high-precision measurement of the axial synchronous and asynchronous rotation error of the spindle of an ultra-precision machine tool, so as to monitor the operation accuracy of the machine tool and the quality of the processed workpiece. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a method for measuring the rotation error of a machine tool spindle based on installation error correction.

[0007] The present invention is achieved through the following technical solutions: A method for measuring a machine tool spindle rotation error based on installation error correction comprises the following steps: Step 1: Install a high-precision plane reflector at the center of the bottom of the spindle cutter head with bolts, and fix the laser interferometer on the workbench below the high-precision plane reflector; Step 2: Quantitatively calculate the measurement error values ​​introduced by the installation error under different installation error conditions, and calculate the corresponding basic synchronous rotation error and residual synchronous error based on the measurement error values, wherein the value of the installation error is equal to the maximum amplitude of the basic synchronous rotation error caused by the installation error, thereby obtaining the corresponding relationship data between different installation error values ​​and the residual synchronous error caused by them; then calculate the installation error control range required to keep the residual synchronous error caused by the installation error within the required measurement accuracy; Step 3: Rotate the spindle at a low speed to obtain the data measured by the laser interferometer. Extract the basic synchronous rotation error and thus the installation error of the measuring device. Then, adjust the installation error by adjusting the installation position of the laser interferometer until the maximum amplitude of the basic synchronous rotation error extracted from the measurement data (i.e., the installation error) reaches the required installation error range determined in step 2. Step 4: After completing the installation error adjustment of the measuring device, adjust the sampling frequency of the laser interferometer so that its sampling frequency matches the spindle speed to avoid sampling point aliasing; then start the spindle and laser interferometer to collect data and obtain the total axial rotation error data of the spindle.

[0008] In the above technical solution, in step 1, the fine-tuning bolts of the laser interferometer optical bracket are adjusted to obtain sufficient reflected light signal intensity; when adjusting, the fine-tuning bolts on one side are first adjusted until the reflected light signal intensity is the highest, and then the fine-tuning bolts on the other side are adjusted until the reflected light signal intensity is the highest, and then the above adjustment steps are repeated until the reflected light signal intensity can no longer be enhanced, at which point the laser interferometer is basically perpendicular to the high-precision plane mirror.

[0009] In the above technical solution, in step 2, the measurement error X is expressed as:

[0010] Where e is the distance that the laser interferometer measurement position deviates from the spindle rotation center, θ is the tilt angle of the plane mirror relative to the spindle axis, and φ is the angular position of the spindle rotation.

[0011] In the above technical solution, in step 4, when the spindle speed is 360 rpm and 480 rpm, the number of sampling points per spindle rotation is set to 10,000 and 6,250 respectively.

[0012] In the above technical solution, after the total spindle axial rotation error data is obtained in step 4, the total spindle axial rotation error data is processed to separate the synchronous rotation error and the asynchronous rotation error.

[0013] In the above technical solution, the sampled data is segmented, and the length of each data segment corresponds to the number of sampling points per spindle rotation, and a total of data for 100 spindle rotations is extracted; then the sampling time domain averaging method is used to calculate the spindle synchronous rotation error; the 100 extracted rotations of data are summed and averaged to obtain the synchronous rotation error at the current spindle speed; the synchronous rotation error of the spindle is subtracted from the total rotation error data of each spindle rotation to obtain the asynchronous rotation error of the spindle.

[0014] The advantages and beneficial effects of the present invention are: The present invention quantitatively calculates the measurement error caused by the installation error of the measuring device, and proposes a control standard and adjustment method for the installation error of the measuring device to meet the required measurement accuracy. A high-precision laser interferometer is used to collect data with high sampling frequency and sampling accuracy. Sufficient sampling data can be obtained when the spindle is working at a high speed, which is suitable for measuring the axial rotation accuracy of high-speed rotating ultra-precision spindles. A high-precision plane reflector installed at the end of the spindle cutter head is used as a measurement reference to avoid additional errors introduced into the spindle axial rotation error measurement data due to the spindle tilt motion error and the radial runout of the standard ball. In addition, the synchronous rotation error and the asynchronous rotation error in the spindle rotation error are separated to meet the high-precision measurement requirements of the spindle axial synchronous and asynchronous rotation errors of the vertical ultra-precision fly-cutting machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the installation structure of the measuring device; Figure 2 It is a schematic diagram of the installation error of the measuring device; Figure 3 This is a data graph of the measurement error amplitude introduced by the installation error of the measuring device; Figure 4 This is a data diagram of measurement error introduced by the installation error of the measuring device under different numbers of sampling points per circle; Figure 5 This is a graph showing the maximum installation error required to keep the residual synchronization error within 1nm at different numbers of sampling points per revolution. Figure 6 This is the data diagram of the total axial rotation error of the spindle at a spindle speed of 300 rpm; Figure 7 This is the data diagram of the total axial rotation error of the spindle at a spindle speed of 480 rpm; Figure 8 This is the spindle axial synchronous rotation error data diagram at a spindle speed of 300 rpm; Figure 9 This is the spindle axial synchronous rotation error data diagram at a spindle speed of 480 rpm; Figure 10 This is the data diagram of the basic synchronous rotation error of the spindle axial direction at a spindle speed of 300 rpm; Figure 11 This is the data diagram of the basic synchronous rotation error of the spindle axial direction at the spindle speed of 480rpm; Figure 12 This is the data diagram of the spindle axial residual synchronous rotation error at a spindle speed of 300 rpm; Figure 13 This is the data diagram of the spindle axial residual synchronous rotation error at a spindle speed of 480 rpm; Figure 14This is the spindle axial asynchronous rotation error data diagram at a spindle speed of 300 rpm; Figure 15 This is the spindle axial asynchronous rotation error data diagram at a spindle speed of 480 rpm.

[0016] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0017] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions of the present invention are further described below with reference to specific embodiments.

[0018] This embodiment provides a method for measuring a machine tool spindle rotation error based on installation error correction, which includes the following steps.

[0019] Step 1: If Figure 1 As shown, a high-precision plane mirror is fixedly installed at the center of the bottom of the spindle cutter head by bolts, and a laser interferometer is fixedly installed on the workbench below the high-precision plane mirror. The fine-tuning bolts of the laser interferometer optical bracket are adjusted to obtain sufficient reflected light signal intensity.

[0020] Because the high-precision flat reflector used is highly accurate and can be considered a standard plane, the requirements for mounting coaxial accuracy are low. This also prevents the influence of spindle radial runout on the spindle axial rotation error measurement data when the reference object is a standard sphere. Furthermore, compared to mounting the reference object at the top of the spindle, mounting it at the center of the cutterhead minimizes the additional error introduced by spindle tilt.

[0021] Specifically, when adjusting the optical bracket of the laser interferometer, first adjust the fine-tuning bolt on one side until the reflected light signal intensity is the highest, then adjust the fine-tuning bolt on the other side until the reflected light signal intensity is the highest, and then repeat the above adjustment steps until the reflected light signal intensity can no longer be increased. At this time, the laser interferometer is basically perpendicular to the high-precision plane mirror.

[0022] Step 2: Quantitatively calculate the measurement error introduced by the measurement device's installation error and analyze its impact on the spindle's basic axial synchronization error and residual synchronization error using simulation. It should be noted that this step is intended to illustrate the impact of installation error on the spindle's basic axial synchronization error and residual synchronization error. This step can be skipped during the actual implementation of the present invention.

[0023] Ideally, the plane mirror is perpendicular to the spindle axis. When the spindle drives the plane mirror to rotate, the data measured by the laser interferometer is the spindle axial error. However, in actual measurement, Figure 2As shown in the figure, the plane mirror cannot be completely perpendicular to the spindle axis and there will be a certain tilt. Moreover, the position measured by the laser interferometer cannot completely coincide with the spindle rotation axis. This will cause the spindle axial rotation error measured by the laser interferometer to include the measurement error caused by the installation error of the measuring instrument (i.e., the installation error of the plane mirror and the laser interferometer). The measurement error X can be expressed as:

[0024] Where e is the distance the laser interferometer measurement position deviates from the spindle's center of rotation, θ is the plane mirror's tilt angle relative to the spindle's axis, and φ is the spindle's angular position. Because this measurement error varies with spindle rotation, and theoretically its frequency of change is the same as the spindle's rotation frequency, it is theoretically present primarily in the fundamental synchronization error—that is, the first-order harmonic of the spindle synchronization error. The magnitude of this error is determined by the product of the plane mirror's mounting tilt angle and the distance the laser interferometer measurement point deviates from the spindle's axis of rotation.

[0025] In order to analyze the influence of the installation error of the measuring device on the synchronous rotation error of the spindle, a simulation calculation is carried out. The amplitude of each order synchronization error of the spindle is calculated when the plane reflector is tilted at an angle of θ = 1°, the measurement position of the laser interferometer deviates from the spindle rotation center by e = 5mm, and 10,000 samples are taken per spindle rotation. Figure 3 As shown in the figure, only the amplitudes of the 1st-50th order harmonics are shown. It can be seen that while the measurement error introduced by this installation error primarily exists in the spindle's axial fundamental synchronization error (first-order harmonic), reaching 87nm, measurement error introduced by the installation error also exists in the residual synchronization error (second-order and higher harmonics). For spindles with general precision, their rotational accuracy is in the micron range, and the residual synchronization error introduced by this is negligible. However, for ultra-precision spindles, their rotational error is required to be in the nanometer range, and the residual synchronization error introduced by this is on the same order of magnitude as the spindle rotation error. Therefore, it is necessary to minimize the impact of this residual synchronization error.

[0026] In addition to the plane mirror tilt angle and the eccentricity of the laser interferometer measurement position, the measurement sampling frequency also affects the magnitude of the residual synchronization error. The simulation calculated the residual synchronization error introduced by the plane mirror tilt angle θ = 1° and the laser interferometer measurement position deviating from the spindle rotation center e = 5mm under different sampling points per spindle rotation. The calculation results are shown in Figure 2. Figure 4As shown in the figure, as the number of measurement sampling points increases, the residual synchronization error introduced by the measurement instrument installation error decreases from 40nm at 2500 sampling points per revolution to less than 5nm at 25,000 sampling points per revolution. The maximum amplitude of the basic synchronization error, as shown in the formula, is 87nm. This is because frequency sampling causes periodic extension of the time domain signal, resulting in aliasing distortion of the spectrum.

[0027] Step 3: Quantitatively calculate the measurement error value introduced by the installation error under different installation error conditions, and calculate the corresponding basic synchronous rotation error and residual synchronous error based on the measurement error value, where the value of the installation error is equal to the maximum amplitude of the basic synchronous rotation error caused by the installation error (i.e. , representing the combined maximum impact of the plane mirror installation tilt and the laser interferometer measurement eccentricity), thereby obtaining the corresponding relationship data between different installation error values ​​and the residual synchronization error caused by them; then calculating the installation error control range required to keep the residual synchronization error caused by the installation error within the required measurement accuracy.

[0028] This step is to reduce the impact of the installation error on the residual synchronization error to an acceptable range in the future. Therefore, the installation error required to control the residual synchronization error caused by the installation error within the required measurement accuracy is calculated. In this embodiment, taking the requirement of achieving a measurement accuracy of 1nm as an example, the maximum installation error required to control the residual synchronization error within 1nm under different numbers of sampling points per circle is calculated. The calculation results are shown as follows: Figure 5 As shown in the figure, it can be seen from the calculation results that increasing the measurement sampling frequency is conducive to reducing the difficulty of installing the measuring device (that is, the maximum allowable installation error is increased).

[0029] Step 4: Let the spindle rotate at a low speed. After obtaining the data measured by the laser interferometer, extract its basic synchronous rotation error, and thus obtain the installation error of the measuring device (the value of the installation error is equal to the maximum amplitude of the basic synchronous rotation error caused by the installation error); then adjust the installation error by adjusting the installation position of the laser interferometer (since the installation tilt error of the plane mirror is difficult to adjust, the influence of the installation error is reduced by adjusting the measurement position of the laser interferometer) until the maximum amplitude of the basic synchronous rotation error extracted from the measurement data (i.e., the installation error) reaches the required measurement device installation error range determined in step 3.

[0030] Step 5: After completing the measurement device installation error adjustment, adjust the laser interferometer sampling frequency to match the spindle speed to avoid sampling point aliasing. Start the spindle and laser interferometer to collect data and obtain the total spindle axial rotation error data.

[0031] After completing the installation error adjustment of the measuring device, the spindle rotation error can be measured. Since the laser interferometer performs discrete sampling in actual measurement, the spindle synchronous rotation error is the average value of multiple-turn measurements. Therefore, it is necessary to ensure that the sampling points are consistent during each spindle rotation. For example, when the spindle speed is 300rpm, the spindle rotates 5 times per second. At this time, if the laser interferometer sampling frequency is set to 50,000Hz, the spindle will be sampled 10,000 times during each rotation. The position of the sampling points is consistent for each rotation, and there will be no aliasing of the sampling points. If the spindle speed is 360rpm, if the laser interferometer sampling frequency is still set to 50,000Hz, the spindle will be sampled 8,333.33 times during each rotation. The position of the sampling points is inconsistent for each rotation, resulting in aliasing of the sampling points, which will cause errors in the calculation of the spindle synchronous rotation error. After setting the spindle speed and laser interferometer sampling frequency, start the spindle and laser interferometer to collect data. In the measurement of the synchronous rotation error of the spindle, it is necessary to measure a sufficient number of circles of data and then perform time domain averaging to ensure the accuracy of the calculation. Generally, the number of sampling circles should be at least 40 circles. In this embodiment, the sampling number of circles is 100 circles, and the sampling time of the spindle at a speed of 300rpm and 480rpm is at least 20 seconds and 12.5 seconds. Since the number of sampling points for each rotation of the spindle is at least 6250 times under different spindle speeds, the installation error of the measuring device needs to be controlled within 6μm. For ultra-precision spindles, the rotation error is generally within the order of hundreds of nanometers, and the installation error is generally in the order of microns, so it can be approximately considered that the maximum rotation error amplitude in the total spindle rotation error measurement data is approximately equal to the size of the installation error of the measuring device. The total spindle rotation error obtained by sampling at spindle speeds of 300rpm and 480rpm is as follows Figure 6 As shown in the figure, the installation error of the measuring device is controlled within 4μm, which is smaller than the required installation error of 6μm. The measurement error of the spindle residual synchronization error introduced by the installation error can be controlled within 1nm.

[0032] Step 6: Process the total spindle axial rotation error data to separate the synchronous rotation error and the asynchronous rotation error.

[0033] In this embodiment, when the spindle speed is 360rpm and 480rpm, the number of sampling points per spindle rotation is 10000 and 6250 respectively. Therefore, the sampled data is segmented, and the length of each data segment corresponds to the number of sampling points per spindle rotation. A total of 100 spindle rotation data is extracted. Then, the time domain averaging method is used to calculate the spindle synchronous rotation error. The 100 extracted data are summed and averaged to obtain the synchronous rotation error at the current spindle speed. The result is as follows: Figure 7 The first-order harmonic in the synchronous error is extracted, which is the basic synchronous rotation error of the main shaft. The measurement results are shown as follows: Figure 8 As shown. Figure 6-Figure 8 The results show that the maximum amplitudes of the total spindle rotation error, synchronous rotation error, and basic synchronous rotation error are all close to 4μm. It also verifies that the maximum amplitude of the total spindle rotation error can be approximately regarded as the installation error of the measuring device. Then, the second-order and above harmonics in the synchronous error are extracted, which are the residual synchronous rotation error of the spindle. The measurement results are as follows Figure 9 As shown, it can be seen that the residual synchronous rotation error of the ultra-precision spindle in this embodiment is within 50nm. It is necessary to control the measurement error of the spindle residual synchronous error introduced by the installation error.

[0034] Then, the synchronous rotation error of the spindle is subtracted from the total rotation error data of each spindle revolution, that is, the asynchronous rotation error of the spindle. In this embodiment, the asynchronous rotation error of the spindle is measured at a spindle speed of 360 rpm and 480 rpm respectively. The measurement results are shown in FIG. Figure 10 As shown in Figure 2, the peak-to-peak value of the asynchronous rotation error of the spindle at a speed of 300 rpm is approximately 35 nm, and at a speed of 480 rpm, the peak-to-peak value of the asynchronous rotation error is approximately 65 nm. The measurement examples presented in this invention demonstrate that the installation accuracy control standards and measurement methods for the spindle axial synchronous and asynchronous rotation accuracy measurement device proposed in this invention can meet the requirements for measuring synchronous and asynchronous spindle rotation errors with nanometer-level rotational accuracy.

[0035] For ease of explanation, spatial relative terms such as "upper", "lower", "left", and "right" are used in the embodiments to illustrate the relationship between one element or feature shown in the figures and another element or feature. It should be understood that, in addition to the orientation shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "above" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0036] Moreover, relational terms such as “first” and “second” are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any actual relationship or order between these components.

[0037] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by other skilled in the art without expending creative labor falls within the scope of protection of the present invention.

Claims

1. A method for measuring the rotation error of a machine tool spindle based on installation error correction, characterized in that: The following steps are involved: Step 1: Install a high-precision plane reflector at the center of the bottom of the spindle cutter head with bolts, and fix the laser interferometer on the workbench below the high-precision plane reflector; Step 2: Quantitatively calculate the measurement error values ​​introduced by the installation error under different installation error conditions, and calculate the corresponding basic synchronous rotation error and residual synchronous error based on the measurement error values, wherein the value of the installation error is equal to the maximum amplitude of the basic synchronous rotation error caused by the installation error, thereby obtaining the corresponding relationship data between different installation error values ​​and the residual synchronous error caused by them; then calculate the installation error control range required to keep the residual synchronous error caused by the installation error within the required measurement accuracy; Step 3: After rotating the spindle at a low speed and obtaining the data measured by the laser interferometer, extract its basic synchronous rotation error, thereby obtaining the installation error of the measuring device; then, adjust the installation error by adjusting the installation position of the laser interferometer until the maximum amplitude of the basic synchronous rotation error extracted from the measurement data reaches the required installation error range determined in step 2; Step 4: After completing the installation error adjustment of the measuring device, adjust the sampling frequency of the laser interferometer so that its sampling frequency matches the spindle speed to avoid sampling point aliasing; then start the spindle and laser interferometer to collect data and obtain the total axial rotation error data of the spindle.

2. The method for measuring the rotation error of a machine tool spindle based on installation error correction according to claim 1, characterized in that: In step 1, adjust the fine-tuning bolts of the laser interferometer optical bracket to obtain sufficient reflected light signal intensity. When adjusting, first adjust the fine-tuning bolts on one side until the reflected light signal intensity is the highest, then adjust the fine-tuning bolts on the other side until the reflected light signal intensity is the highest, and then repeat the above adjustment steps until the reflected light signal intensity can no longer be increased.

3. The method for measuring the rotation error of a machine tool spindle based on installation error correction according to claim 1, characterized in that: In step 2, the measurement error X is expressed as:

4. Where e is the distance that the laser interferometer measurement position deviates from the spindle rotation center, θ is the tilt angle of the plane reflector relative to the spindle axis, and φ is the angular position of the spindle rotation.

5. The method for measuring the rotation error of a machine tool spindle based on installation error correction according to claim 1, characterized in that: In step 4, when the spindle speed is 360 rpm and 480 rpm, the number of sampling points per spindle rotation is set to 10,000 and 6,250 respectively.

6. The method for measuring machine tool spindle rotation error based on installation error correction according to claim 1, characterized in that: After obtaining the total spindle axial rotation error data in step 4, the total spindle axial rotation error data is processed to separate the synchronous rotation error and the asynchronous rotation error.

7. The method for measuring the rotation error of a machine tool spindle based on installation error correction according to claim 5, characterized in that: The sampled data is segmented, and the length of each data segment corresponds to the number of sampling points per spindle rotation. A total of 100 spindle rotation data are extracted. Then, the time domain averaging method is used to calculate the spindle synchronous rotation error. The 100 extracted rotation data are summed and averaged to obtain the synchronous rotation error at the current spindle speed. The synchronous rotation error of the spindle is subtracted from the total rotation error data of each spindle rotation to obtain the asynchronous rotation error of the spindle.

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