A spindle motion tilt error compensation method and system for a numerical control machine tool

Abstract

The application discloses a kind of main shaft movement inclination error compensation method and system for numerical control machine tool, the method includes: determining the installation position of the first section and the second section of numerical control machine tool and non-contact laser displacement sensor, obtains numerical control machine tool radial error data;To numerical control machine tool radial error data in turn is filtered, parameterization and reconstruction processing, obtain the numerical control machine tool radial error data after pre-processing;According to the numerical control machine tool radial error data after pre-processing, the feed rate of numerical control machine tool cutting tool is adaptively compensated, and the feed rate of numerical control machine tool cutting tool after compensation is obtained.By using the application, the output angle of machine tool can be standardized, and the machining precision of numerical control machine tool for parts can be improved.The application is a kind of main shaft movement inclination error compensation method and system for numerical control machine tool, which can be widely applied in the field of intelligent manufacturing technology.

Description

Technical Field

[0001] This invention relates to the field of intelligent manufacturing technology, and in particular to a method and system for compensating for spindle motion tilt error in CNC machine tools. Background Technology

[0002] The spindle is a key functional component of a machine tool, and its accuracy (the spatial positional accuracy of the spindle's axis of rotation) largely determines the machining accuracy of a CNC machine tool. The spindle's axis of rotation serves as the mounting and positioning reference for the tool or workpiece; its spatial accuracy ensures that the machine tool can produce relatively perfect parts. Manufacturing errors exist in the spindle, and under the combined influence of complex working conditions, its axis of rotation will inevitably deviate from the ideal position, resulting in machining errors. This makes testing and real-time compensation technologies indispensable tools for spindle accuracy and error analysis.

[0003] Modern machine tools are primarily precision machine tools. During machining, eliminating human error, errors such as roundness and end-face flatness of the machined parts originate from spindle rotation errors. It's important to note that if the spindle motion is ideal, its axis of rotation remains constant in space relative to the tool holder (a specific reference point). However, in actual use, the position of the spindle's axis of rotation will always change due to the machine tool itself or various external factors; that is, rotational error is always present. Furthermore, the higher the precision level of the machine tool, the greater the proportion of spindle motion error's influence. In real-world scenarios, improper operation can cause the machine tool's output angle to fail to meet actual requirements, thereby reducing the precision of the machined parts. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a method and system for compensating for spindle motion tilt error in CNC machine tools, which can standardize the output angle of the machine tool and thereby improve the machining accuracy of parts by the CNC machine tool.

[0005] The first technical solution adopted in this invention is: a method for compensating for spindle motion tilt error in CNC machine tools, comprising the following steps:

[0006] Determine the first and second cross sections of the CNC machine tool and the installation position of the non-contact laser displacement sensor to obtain the radial error data of the CNC machine tool;

[0007] The radial error data of CNC machine tools is filtered, parameterized and reconstructed sequentially to obtain the preprocessed radial error data of CNC machine tools.

[0008] The feed rate of the CNC machine tool cutting tool is adaptively compensated based on the preprocessed radial error data of the CNC machine tool, and the compensated feed rate of the CNC machine tool cutting tool is obtained.

[0009] Furthermore, the step of measuring the spindle rotation axis trajectory of the CNC machine tool using the point measurement method based on a non-contact laser displacement sensor to obtain the spindle axial machining error data under CNC machine tool load conditions specifically includes:

[0010] Determine the first section and the second section of the CNC machine tool. The first section represents the spindle section at the motor end of the CNC machine tool, and the second section represents the spindle section at the motor end of the CNC machine tool.

[0011] The first non-contact laser displacement sensor and the second non-contact laser displacement sensor are installed at a 90° angle on the first section of the CNC machine tool, and the third non-contact laser displacement sensor and the fourth non-contact laser displacement sensor are installed at a 90° angle on the second section of the CNC machine tool.

[0012] Furthermore, the step of sequentially filtering, parameterizing, and reconstructing the radial error data of the CNC machine tool to obtain the preprocessed radial error data specifically includes:

[0013] Based on the fact that the CNC machine tool is running under no-load conditions, the radial error data of the CNC machine tool is obtained by a non-contact laser displacement sensor. The radial error data of the CNC machine tool includes the installation eccentricity error of the CNC machine tool, the spindle shape error of the CNC machine tool, and the radial rotation error of the spindle of the CNC machine tool.

[0014] The radial error data of CNC machine tool is filtered by the first harmonic signal filtering method to obtain the radial error data of CNC machine tool after eliminating the eccentricity error.

[0015] The spindle shape error of the CNC machine tool in the radial error data of the CNC machine tool after eliminating the eccentricity error is parameterized to obtain the parameterized spindle shape error of the CNC machine tool.

[0016] The least squares circular error evaluation method is used to reconstruct the radial rotation error of the CNC machine tool spindle in the radial error data of the CNC machine tool after eliminating the eccentricity error, and the reconstructed radial rotation error of the CNC machine tool spindle is obtained.

[0017] By combining the CNC machine tool spindle shape error after parameterization with the reconstructed CNC machine tool spindle radial rotation error, the preprocessed CNC machine tool radial error data is obtained.

[0018] Furthermore, the step of filtering the radial error data of the CNC machine tool using the first harmonic signal filtering method to obtain the radial error data of the CNC machine tool after eliminating the eccentricity error specifically includes:

[0019] The radial error data of CNC machine tools is divided into intervals and data anomalies are removed to obtain preprocessed radial error data of CNC machine tools.

[0020] Based on the eccentricity of the non-contact laser displacement sensor, the residual error of the pre-processed radial error data of the CNC machine tool is obtained;

[0021] The first Fourier coefficient of the residual error of the preprocessed radial error data of the CNC machine tool is obtained and combined with the preprocessed radial error data of the CNC machine tool for elimination processing to obtain the radial error data of the CNC machine tool after eliminating the eccentricity error.

[0022] Furthermore, the expression for parameterizing the spindle shape error of the CNC machine tool is as follows:

[0023] ;

[0024] In the above formula, The outer contour of the measured section of the CNC machine tool spindle is represented by the first... Shape error of each sampling point This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. Indicates the number of sampling points. This indicates the number of revolutions a CNC machine tool can continuously operate under no-load conditions. This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. This indicates the number of data collected by the sensor under spindle no-load conditions. One data point, Indicates the first Each sampling point is Data collected by the circle , Indicates in All sampling points collected within the circle were the first... Data .

[0025] Furthermore, the step of reconstructing the radial rotation error of the CNC machine tool spindle from the radial error data after eliminating eccentricity error using the least squares circular error evaluation method to obtain the reconstructed radial rotation error of the CNC machine tool spindle specifically includes:

[0026] Construct the absolute coordinate system of the CNC machine tool based on the average line of the spindle rotation axis;

[0027] A vector is set to rotate clockwise around the X-axis and the Y-axis of the absolute coordinate system of the CNC machine tool in sequence to obtain the deflection angle;

[0028] The radial rotation error of the CNC machine tool spindle is reconstructed based on the deflection angle to obtain the reconstructed radial rotation error of the CNC machine tool spindle.

[0029] Furthermore, the step of adaptively compensating the feed rate of the CNC machine tool cutting tool based on the preprocessed radial error data of the CNC machine tool to obtain the compensated feed rate of the CNC machine tool cutting tool specifically includes:

[0030] Construct a Cartesian rectangular coordinate system for the CNC machine tool based on the average line of the spindle rotation axis;

[0031] Based on the Cartesian rectangular coordinate system of CNC machine tool space, determine the coordinate position of CNC machine tool cutting tool, the mapping relationship expression between the first section axis offset and the second section axis offset;

[0032] The feed compensation amount of the CNC machine tool cutting tool is determined based on the mapping relationship expression, and the compensation threshold is preset.

[0033] If the feed compensation amount of the CNC machine tool cutting tool does not meet the preset compensation threshold, adaptive compensation will not be performed;

[0034] If the feed compensation of the CNC machine tool cutting tool meets the preset compensation threshold, the feed of the CNC machine tool cutting tool is adaptively compensated by the preprocessed radial error data of the CNC machine tool to obtain the compensated feed of the CNC machine tool cutting tool.

[0035] Furthermore, the mapping relationship between the coordinate position of the CNC machine tool cutting tool, the axis offset of the first section, and the axis offset of the second section is specifically shown below:

[0036] ;

[0037] In the above formula, This indicates the axial distance between the first and second measured sections. This indicates the axial distance between the tool position and the measured second cross-section, which changes in real time during the machining process. and These represent the first and second cross-sections being measured, respectively. Radial rotation error in the axial direction, The adaptive compensation amount of the tool feed rate is indicated in Components in the axial direction.

[0038] Furthermore, it also includes constructing a mapping relationship data table based on the load size of the CNC machine tool, the feed rate of the CNC machine tool cutting tool, and the radial error data of the CNC machine tool, so as to realize the self-prediction of the adaptive compensation amount of the feed rate of the CNC machine tool cutting tool.

[0039] The second technical solution adopted in this invention is: a spindle motion tilt error compensation system for CNC machine tools, comprising:

[0040] The first module is used to determine the first and second cross sections of the CNC machine tool and the installation position of the non-contact laser displacement sensor, and to obtain the radial error data of the CNC machine tool.

[0041] The second module is used to sequentially filter, parameterize and reconstruct the radial error data of the CNC machine tool to obtain the preprocessed radial error data of the CNC machine tool.

[0042] The third module is used to adaptively compensate the feed rate of the CNC machine tool cutting tool based on the pre-processed radial error data of the CNC machine tool, so as to obtain the compensated feed rate of the CNC machine tool cutting tool.

[0043] The beneficial effects of the method and system of this invention are as follows: This invention obtains radial error data of the CNC machine tool by determining the first and second cross sections and the installation position of the non-contact laser displacement sensor. The radial error data is then filtered, parameterized, and reconstructed sequentially to obtain pre-processed radial error data. Based on the data analysis, the tilting condition of the spindle under cutting load is determined, and the rotation axis position of the CNC machine tool is reconstructed. This solves the problems of data loss, data mutation, and non-standard machine tool output angle affecting the results in actual scenarios. Finally, the feed rate of the CNC machine tool cutting tool is adaptively compensated based on the pre-processed radial error data. This allows for the prediction of the adaptive compensation amount of the cutting tool feed rate and comparison with the actual compensation amount, thereby improving the machining accuracy of the CNC machine tool on the parts. Attached Figure Description

[0044] Figure 1 This is a flowchart of the steps of a spindle motion tilt error compensation method for CNC machine tools according to the present invention;

[0045] Figure 2 This is a structural block diagram of a spindle motion tilt error compensation system for CNC machine tools according to the present invention;

[0046] Figure 3 This is a schematic diagram of real-time compensation for spindle motion tilt error of a CNC machine tool provided in a specific embodiment of the present invention;

[0047] Figure 4This is a schematic diagram of the installation of a laser displacement sensor based on the working principle of the measuring point method provided in a specific embodiment of the present invention;

[0048] Figure 5 This is a schematic diagram illustrating the real-time information interaction principle between a CNC machine tool and a sensor, provided in a specific embodiment of the present invention.

[0049] Figure 6 This is a schematic diagram illustrating the principle of the CNC machine tool spindle rotation trajectory testing method provided in a specific embodiment of the present invention;

[0050] Figure 7 This is a schematic diagram of spindle tilt error calculation provided in a specific embodiment of the present invention. Detailed Implementation

[0051] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The step numbers in the following embodiments are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

[0052] Reference Figure 1 This invention provides a method for compensating for spindle motion tilt error in CNC machine tools, the method comprising the following steps:

[0053] S100. Determine the first and second sections of the CNC machine tool and the installation position of the non-contact laser displacement sensor, and obtain the radial error data of the CNC machine tool;

[0054] Specifically, a first section (measuring point A) and a second section (measuring point B) of the CNC machine tool are determined. The first section represents the spindle section at the motor end of the CNC machine tool, and the second section represents the spindle section at the motor end of the CNC machine tool. A first non-contact laser displacement sensor and a second non-contact laser displacement sensor are installed at 90° angles on the first section of the CNC machine tool, and a third non-contact laser displacement sensor and a fourth non-contact laser displacement sensor are installed at 90° angles on the second section of the CNC machine tool.

[0055] Furthermore, it should be noted that in this embodiment, the real-time measurement method for the machining error generated by the CNC machine tool spindle under cutting force load is first determined to be the point measurement method based on a non-contact laser displacement sensor, referring to... Figure 4 The measurement principle is as follows: Four non-contact laser displacement sensors are used: two pairs of mutually perpendicular displacement sensors are used at different cross-sectional positions of the spindle. The first and second non-contact laser displacement sensors measure the spindle error at the first cross-section (far from the motor end); the third and fourth non-contact laser displacement sensors measure the spindle error at the second cross-section (near the motor end).

[0056] Furthermore, determine the required hardware measurement equipment and its data transmission path, such as... Figure 5 As shown, the hardware measurement equipment includes: a CNC machine tool system, a programmable logic controller (PLC), a network switch, a non-contact laser displacement sensor, a sensor bracket, a power-to-voltage converter, an AI-powered machine, and I / O modules. Under load, to achieve adaptive compensation of the CNC machine tool tool, it relies on data collected in real-time by four sensors: the axial position coordinates of the tool during operation, and the angular position information of the machine tool spindle—three parameters that change over time. Therefore, the AI-powered machine receives the dynamic data provided by the sensors, the tool coordinate position, and the spindle angular position information output by the CNC machine tool in real time, performs instant data processing and calculation internally, ultimately derives the compensation amount, and feeds it back to the compensation interface of the CNC machine tool to optimize machining accuracy.

[0057] Secondly, it is necessary to determine the sensor installation method, position parameters, and geometric parameters of the CNC machine tool spindle. The installation of the laser displacement sensor needs to ensure stability, with two sensors located on the same cross section distributed at 90°. In order to avoid eccentricity errors during the measurement process, the intersection of the two sensors should be located at the spindle axis as much as possible. Therefore, a sensor bracket that can be precisely adjusted in the measurement direction needs to be designed. The geometric parameters include the axial distance between the two measured cross sections, the radius of the spindle, the length of the spindle, and the rotation speed and direction of the spindle.

[0058] Finally, a laser displacement sensor is used to measure the rotation axis trajectory of the CNC machine tool spindle, such as... Figure 6 As shown, based on the spindle spatial error analysis, the spindle axial error is spatially distributed into radial error, axial error, and tilt error. The radial error of the first section can be measured using a first non-contact laser displacement sensor and a second non-contact laser displacement sensor; the radial error of the second section can be measured using a third non-contact laser displacement sensor and a fourth non-contact laser displacement sensor; the spindle axial tilt error is obtained by coupling the radial runout errors of the first and second sections; the axial error is negligible and therefore ignored. Based on the machine tool spindle error measurement principle of the measuring point method, the radial error measured by the sensors can be divided into four parts: sensor installation eccentricity error, spindle measured section shape error, radial rotation error, and random errors caused by external factors. To minimize the influence of the environment, the systematic errors of sensor installation eccentricity error and spindle measured section shape error are separated using data processing methods to obtain the spindle radial rotation error that varies with time.

[0059] S200: The radial error data of the CNC machine tool is filtered, parameterized and reconstructed in sequence to obtain the preprocessed radial error data of the CNC machine tool.

[0060] S210. Based on the CNC machine tool operating under no-load conditions, radial error data of the CNC machine tool is obtained through a non-contact laser displacement sensor. The radial error data of the CNC machine tool includes CNC machine tool installation eccentricity error, CNC machine tool spindle shape error, and CNC machine tool spindle radial rotation error.

[0061] S220. The radial error data of the CNC machine tool is filtered by the first harmonic signal filtering method to obtain the radial error data of the CNC machine tool after eliminating the eccentricity error.

[0062] Specifically, the radial error data of the CNC machine tool is divided into intervals and data anomaly removal is performed to obtain preprocessed radial error data of the CNC machine tool; the residual error of the preprocessed radial error data of the CNC machine tool is obtained based on the eccentricity of the non-contact laser displacement sensor; the first Fourier coefficient of the residual error of the preprocessed radial error data of the CNC machine tool is obtained and combined with the preprocessed radial error data of the CNC machine tool for elimination processing to obtain radial error data of the CNC machine tool after eliminating eccentricity error.

[0063] In this embodiment, the sensor installation eccentricity error is separated using the "first harmonic signal filtering" method under machine tool no-load conditions. This error separation is achieved during the initial data acquisition phase, ensuring the machine tool operates under no-load conditions. First, the machine tool spindle rotates continuously. During the lap, the data acquisition system will read data at 10ms intervals. Under this setting, theoretically, the system will collect data after each lap. This means that every 10ms, the AI ​​will receive a set of comprehensive information including data from four sensors, the rotation angle of the machine tool spindle, and the specific position coordinates of the cutting tool. The entire acquisition process will generate a total of... Group data.

[0064] After data acquisition is completed, packet loss during data transmission and the misalignment of the machine tool spindle rotation angle during each revolution (theoretically, each revolution should have...) are considered. Each spindle angle should correspond one-to-one, but this cannot be guaranteed in practical applications. (Reset) And divide 360° into equal parts The collected data will be distributed according to these intervals. The data is divided into intervals, and the collected values ​​within the same interval are counted as one sampling point, ensuring that there is at least one sampling point in each angle interval. At the same time, any data that has a sudden change in the data collected by the sensor is removed.

[0065] Since the sensor needs to be manually installed when measuring the spindle rotation error, this manual operation will inevitably introduce installation eccentricity error. However, since the installation eccentricity error is a first harmonic signal, its impact on the measurement results can be minimized by filtering the first harmonic. Assuming a first non-contact laser displacement sensor is located at the first cross-section... Measurements are taken along the X-axis (the direction of tool feed during machining), and the data collected by the sensor is... for: .

[0066] Where O is the theoretical axis determined by two laser displacement sensors, A is the actual axis, and OA represents the eccentricity.

[0067] by Taking the data collected by the sensor as an example The residual error is calculated using the following expression:

[0068] ;

[0069] The expression for the first-order Fourier coefficients is:

[0070] ;

[0071] ;

[0072] The expression for eliminating eccentricity error is:

[0073] ;

[0074] That is The sensor's acquired data after eliminating installation eccentricity errors is the value at this point. It represents the sum of the radial rotation error of the machine tool spindle and the shape error of the measured section of the spindle.

[0075] S230. Perform parameterization processing on the CNC machine tool spindle shape error in the radial error data of the CNC machine tool after eliminating eccentricity error, and obtain the parameterized CNC machine tool spindle shape error.

[0076] In this embodiment, the parameterization of the CNC machine tool spindle shape error is completed by processing the data collected by the sensor under the machine tool's no-load state. The expression is as follows:

[0077] ;

[0078] In the above formula, The outer contour of the measured section of the CNC machine tool spindle is represented by the first... Shape error of each sampling point This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. Indicates the number of sampling points. This indicates the number of revolutions a CNC machine tool can continuously operate under no-load conditions. This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. This indicates the number of data collected by the sensor under spindle no-load conditions. One data point, Indicates the first Each sampling point is Data collected by the circle , Indicates in All sampling points collected within the circle were the first... Data .

[0079] Utilizing this continuity By fitting the principal axis shape error and principal axis radius of each sampling point, the complete shape curve of the measured section of the principal axis and the shape error parameters of each point can be obtained.

[0080] S240. The radial rotation error of the CNC machine tool spindle in the radial error data of the CNC machine tool after eliminating the eccentricity error is reconstructed by the least squares circular error evaluation method to obtain the reconstructed radial rotation error of the CNC machine tool spindle.

[0081] Specifically, an absolute coordinate system for the CNC machine tool is constructed based on the average line of the spindle rotation axis; a vector is set to rotate clockwise around the X-axis and Y-axis of the absolute coordinate system of the CNC machine tool in sequence to obtain the deflection angle; the radial rotation error of the CNC machine tool spindle is reconstructed based on the deflection angle to obtain the reconstructed radial rotation error of the CNC machine tool spindle.

[0082] In this embodiment, based on the "least squares circular error evaluation method" theory, the position reconstruction of the CNC machine tool spindle rotation axis is completed, such as... Figure 7 As shown, based on the uniqueness of the average line of the spindle rotation axis, an absolute coordinate system is established using the average line of the axis. The first section is selected as the reference plane, and the radial rotation error measured by this section is used as the reference. The spindle tilt angle rotation error can be obtained from the radial rotation error measured by the second section.

[0083] Based on the aforementioned absolute coordinate system, assume there is a vector Let its starting coordinates be The endpoint coordinates are Then the vector First rotate clockwise around the X-axis Then rotate clockwise around the Y-axis After the transformation, let the new vector be... . The starting point of the coordinates is The endpoint coordinates are New vector for:

[0084] ;

[0085] in , The coordinate transformation matrix (curl) representing the clockwise rotation of a vector around the X and Y axes can be expressed by the following formula:

[0086] ;

[0087] ;

[0088] The deflection angle, after being adjusted, is expressed as follows:

[0089] ;

[0090] ;

[0091] Analysis shows that when When the size is sufficiently large, the effect of the rotation sequence of the vector around the axis on the deflection angle can be ignored, while the radial rotation error of a high-precision spindle is at the micrometer or even sub-micrometer level. Since it's at the millimeter level, the calculation result for the deflection angle can be simplified to:

[0092] ;

[0093] ;

[0094] In the above formula, This indicates the angle of clockwise rotation around the X-axis. This indicates the angle of clockwise rotation around the Y-axis.

[0095] S250. By combining the CNC machine tool spindle shape error after parameterization with the reconstructed CNC machine tool spindle radial rotation error, the preprocessed CNC machine tool radial error data is obtained.

[0096] S300. Based on the pre-processed radial error data of the CNC machine tool, adaptive compensation is performed on the feed rate of the CNC machine tool cutting tool to obtain the compensated feed rate of the CNC machine tool cutting tool.

[0097] Specifically, a Cartesian coordinate system for the CNC machine tool is constructed based on the average line of the spindle rotation axis. Based on this Cartesian coordinate system, the coordinate position of the CNC machine tool cutting tool and the mapping relationship between the first section axis offset and the second section axis offset are determined. The feed compensation amount for the CNC machine tool cutting tool is determined based on the mapping relationship, and a preset compensation threshold is established. If the feed compensation amount for the CNC machine tool cutting tool does not meet the preset compensation threshold, no adaptive compensation is performed. If the feed compensation amount for the CNC machine tool cutting tool meets the preset compensation threshold, adaptive compensation is performed on the feed amount of the CNC machine tool cutting tool using pre-processed radial error data, resulting in the compensated feed amount.

[0098] In this embodiment, based on the analysis of the CNC machine tool working process, in addition to the radial clearance at both ends of the spindle causing the offset of the axis trajectory, the cutting tool also applies a radial load to the spindle during the machining process, causing the spindle to deform in the radial direction. Therefore, the adaptive compensation amount of the tool feed is a function of the axial coordinate position of the cutting tool, the axis offset of the measured first cross-section end, and the axis offset of the measured second cross-section end.

[0099] Establish a spatial Cartesian coordinate system based on the average line of the main spindle rotation axis, and take the theoretical axis center of the measured second section end as the origin of the coordinate system. Using the mapping relationship, we obtain:

[0100] ;

[0101] In the above formula, This indicates the axial distance between the first and second measured sections. This indicates the axial distance between the tool position and the measured second cross-section, which changes in real time during the machining process. and These represent the first and second cross-sections being measured, respectively. Radial rotation error in the axial direction, The adaptive compensation amount of the tool feed rate is indicated in Components in the axial direction.

[0102] Based on the actual wobble analysis of the cutting tool during operation, in addition to the directly calculated projection value in the X-axis direction, the wobble of the spindle in the Y-axis direction also affects the relative position of the cutting tool and the spindle. Therefore, the feed compensation of the cutting tool should also consider the influence of radial rotation error in the Y-axis direction.

[0103] ;

[0104] in, This indicates the radius of the measured section of the main shaft. This indicates the radial rotation error of the cutting tool's position along the Y-axis. This refers to the component of the adaptive compensation amount of the tool feed rate in the Y-axis direction.

[0105] In a real-time spindle trajectory monitoring system, when the spindle trajectory deviates from the origin, it should be compensated accordingly. However, given the system's response time and the tool's feed accuracy, in practical applications, this method may actually lead to a serious decrease in machining accuracy. Therefore, it is necessary to set a threshold within the tool's compensation accuracy range. Compensation should only be performed when the trajectory exceeds this threshold; otherwise, it should be ignored.

[0106] Finally, it should be noted that in this embodiment, a parameter mapping relationship between cutting speed, load magnitude, and tool adaptive compensation amount is established. Each parameter is changed using the controlled variable method, and the changes in tool compensation amount are recorded to establish a CNC machine tool cutting parameter sample set. Based on this sample set, a bivariate nonlinear regression equation is used to approximate the data, obtaining the mapping relationship between each parameter and the cutting tool's adaptive compensation amount during the CNC machine tool cutting load machining process. This mapping relationship can be used to predict the adaptive compensation amount of the cutting tool feed rate. The predicted and actual values ​​are used as a comparison to diagnose CNC machine tool faults.

[0107] Reference Figure 2 A spindle motion tilt error compensation system for CNC machine tools, comprising:

[0108] The first module 201 is used to determine the first and second sections of the CNC machine tool and the installation position of the non-contact laser displacement sensor, and to obtain the radial error data of the CNC machine tool.

[0109] The second module 202 is used to sequentially filter, parameterize and reconstruct the radial error data of the CNC machine tool to obtain the preprocessed radial error data of the CNC machine tool.

[0110] The third module 203 is used to adaptively compensate the feed rate of the CNC machine tool cutting tool based on the pre-processed radial error data of the CNC machine tool, so as to obtain the compensated feed rate of the CNC machine tool cutting tool.

[0111] The content of the above method embodiments is applicable to this system embodiment. The specific functions implemented in this system embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0112] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A method for compensating spindle motion tilt error in CNC machine tools, characterized in that, Includes the following steps: Determine the first and second cross sections of the CNC machine tool and the installation positions of the non-contact laser displacement sensor, and obtain the radial error data of the CNC machine tool, including: Determine the first section and the second section of the CNC machine tool. The first section represents the spindle section at the motor end of the CNC machine tool, and the second section represents the spindle section at the motor end of the CNC machine tool. The first non-contact laser displacement sensor and the second non-contact laser displacement sensor are installed at 90° on the first section of the CNC machine tool, and the third non-contact laser displacement sensor and the fourth non-contact laser displacement sensor are installed at 90° on the second section of the CNC machine tool. Based on the fact that the CNC machine tool is running under no-load conditions, the radial error data of the CNC machine tool is obtained by a non-contact laser displacement sensor. The radial error data of the CNC machine tool includes the installation eccentricity error of the CNC machine tool, the spindle shape error of the CNC machine tool, and the radial rotation error of the spindle of the CNC machine tool. The radial error data of CNC machine tools is divided into intervals and data anomalies are removed to obtain preprocessed radial error data of CNC machine tools. Based on the eccentricity of the non-contact laser displacement sensor, the residual error of the pre-processed radial error data of the CNC machine tool is obtained; The first Fourier coefficient of the residual error of the radial error data of the preprocessed CNC machine tool is obtained and combined with the radial error data of the preprocessed CNC machine tool to perform elimination processing, so as to obtain the radial error data of the CNC machine tool after eliminating the eccentricity error. The spindle shape error of the CNC machine tool in the radial error data of the CNC machine tool after eliminating the eccentricity error is parameterized to obtain the parameterized spindle shape error of the CNC machine tool. Construct the absolute coordinate system of the CNC machine tool based on the average line of the spindle rotation axis; A vector is set to rotate clockwise around the X-axis and the Y-axis of the absolute coordinate system of the CNC machine tool in sequence to obtain the deflection angle; The radial rotation error of the CNC machine tool spindle is reconstructed based on the deflection angle to obtain the reconstructed radial rotation error of the CNC machine tool spindle. By combining the CNC machine tool spindle shape error after parameterization with the reconstructed CNC machine tool spindle radial rotation error, the preprocessed CNC machine tool radial error data is obtained. Construct a Cartesian rectangular coordinate system for the CNC machine tool based on the average line of the spindle rotation axis; Based on the Cartesian rectangular coordinate system of CNC machine tool space, determine the coordinate position of CNC machine tool cutting tool, the mapping relationship expression between the first section axis offset and the second section axis offset; The feed compensation amount of the CNC machine tool cutting tool is determined based on the mapping relationship expression, and the compensation threshold is preset. If the feed compensation amount of the CNC machine tool cutting tool does not meet the preset compensation threshold, adaptive compensation will not be performed; If the feed compensation of the CNC machine tool cutting tool meets the preset compensation threshold, the feed of the CNC machine tool cutting tool is adaptively compensated by the preprocessed radial error data of the CNC machine tool to obtain the compensated feed of the CNC machine tool cutting tool.

2. The method for compensating spindle motion tilt error in CNC machine tools according to claim 1, characterized in that, The expression for parameterizing the spindle shape error of the CNC machine tool is as follows: ； In the above formula, The outer contour of the measured section of the CNC machine tool spindle is represented by the first... Shape error of each sampling point This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. Indicates the number of sampling points. This indicates the number of revolutions a CNC machine tool can continuously operate under no-load conditions. This indicates that the CNC machine tool is working continuously under no-load conditions. The mean of all data collected by the sensor during the looping process, after eliminating installation eccentricity errors. Indicates belonging to the first The mean of the data from each sampling point. This indicates the number of data collected by the sensor under spindle no-load conditions. One data point, Indicates the first Each sampling point is at Data collected by the circle , Indicates in All sampling points collected within the circle were the first... Data .

3. The method for compensating spindle motion tilt error in CNC machine tools according to claim 2, characterized in that, The mapping relationship between the coordinate position of the CNC machine tool cutting tool, the axis offset of the first section, and the axis offset of the second section is specifically expressed as follows: ； In the above formula, This indicates the axial distance between the first and second measured sections. This indicates the axial distance between the tool position and the measured second cross-section, which changes in real time during the machining process. and These represent the first and second cross-sections being measured, respectively. Radial rotation error in the axial direction, The adaptive compensation amount of the tool feed rate is indicated in Components in the axial direction.

4. The method for compensating spindle motion tilt error in CNC machine tools according to claim 3, characterized in that, It also includes constructing a mapping relationship data table based on the load size of the CNC machine tool, the feed rate of the CNC machine tool cutting tool, and the radial error data of the CNC machine tool, so as to realize the self-prediction of the adaptive compensation amount of the feed rate of the CNC machine tool cutting tool.

5. A spindle motion tilt error compensation system for CNC machine tools, characterized in that, Includes the following modules: The first module is used to determine the first and second cross sections of the CNC machine tool and the installation position of the non-contact laser displacement sensor, and to acquire radial error data of the CNC machine tool, including: Determine the first section and the second section of the CNC machine tool. The first section represents the spindle section at the motor end of the CNC machine tool, and the second section represents the spindle section at the motor end of the CNC machine tool. The first non-contact laser displacement sensor and the second non-contact laser displacement sensor are installed at 90° on the first section of the CNC machine tool, and the third non-contact laser displacement sensor and the fourth non-contact laser displacement sensor are installed at 90° on the second section of the CNC machine tool. The second module is used to acquire radial error data of the CNC machine tool through a non-contact laser displacement sensor when the CNC machine tool is running under no-load conditions. The radial error data of the CNC machine tool includes CNC machine tool installation eccentricity error, CNC machine tool spindle shape error, and CNC machine tool spindle radial rotation error. The radial error data of CNC machine tools is divided into intervals and data anomalies are removed to obtain preprocessed radial error data of CNC machine tools. Based on the eccentricity of the non-contact laser displacement sensor, the residual error of the pre-processed radial error data of the CNC machine tool is obtained; The first Fourier coefficient of the residual error of the radial error data of the preprocessed CNC machine tool is obtained and combined with the radial error data of the preprocessed CNC machine tool to perform elimination processing, so as to obtain the radial error data of the CNC machine tool after eliminating the eccentricity error. The spindle shape error of the CNC machine tool in the radial error data of the CNC machine tool after eliminating the eccentricity error is parameterized to obtain the parameterized spindle shape error of the CNC machine tool. Construct the absolute coordinate system of the CNC machine tool based on the average line of the spindle rotation axis; A vector is set to rotate clockwise around the X-axis and the Y-axis of the absolute coordinate system of the CNC machine tool in sequence to obtain the deflection angle; The radial rotation error of the CNC machine tool spindle is reconstructed based on the deflection angle to obtain the reconstructed radial rotation error of the CNC machine tool spindle. By combining the CNC machine tool spindle shape error after parameterization with the reconstructed CNC machine tool spindle radial rotation error, the preprocessed CNC machine tool radial error data is obtained. The third module is used to construct a Cartesian coordinate system for the CNC machine tool space based on the average line of the rotation axis of the CNC machine tool spindle. Based on the Cartesian rectangular coordinate system of CNC machine tool space, determine the coordinate position of CNC machine tool cutting tool, the mapping relationship expression between the first section axis offset and the second section axis offset; The feed compensation amount of the CNC machine tool cutting tool is determined based on the mapping relationship expression, and the compensation threshold is preset. If the feed compensation amount of the CNC machine tool cutting tool does not meet the preset compensation threshold, adaptive compensation will not be performed; If the feed compensation of the CNC machine tool cutting tool meets the preset compensation threshold, the feed of the CNC machine tool cutting tool is adaptively compensated by the preprocessed radial error data of the CNC machine tool to obtain the compensated feed of the CNC machine tool cutting tool.

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