Workpiece machining reference circle center alignment method based on computer-aided calculation

Abstract

The application relates to the technical field of part machining, in particular to a workpiece machining reference circle center alignment method based on computer-aided calculation, which comprises the following steps: circular curve fitting is performed on all sampling data points on a machining part to obtain a fitted circular curve; the variation difference of each sampling data point is obtained by analyzing the distribution of each sampling data point on the fitted circular curve; the overlap between the fitted circular curves before and after sampling frequency adjustment is analyzed to obtain a frequency adjustment factor; a frequency adjustment weight is obtained according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points and the frequency adjustment factor; different sampling frequencies are obtained based on the frequency adjustment weight, and the variation between the center positions of the fitted circular curves under different sampling frequencies is analyzed to obtain the reference circle center of the machining part. The position of the obtained reference circle center of the machining part is more accurate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of part processing, in particular to a workpiece processing reference circle center alignment method based on computer-aided calculation. BACKGROUND

[0002] When mechanical equipment is processed, the reference of the processed part needs to be ensured to ensure the processing precision, and the reference circle center alignment is completed through manual measurement or simple mechanical methods. With the development of computer-aided technology, computer-aided calculation (CAM) method is widely used in modern manufacturing to realize this process. Through computer-aided means, the processing data can be collected and analyzed to improve the accuracy and efficiency of the alignment. When high-precision materials such as aerospace are processed and manufactured, the parts need to be precisely processed. Since the method of obtaining the reference circle center by obtaining edge information from the image angle is not suitable for high-precision processed parts.

[0003] The method of obtaining the reference circle center of the processed part by rotating the processed part and installing a laser displacement sensor on the side surface of the processed part, and obtaining a plurality of sampling data points by using the laser displacement sensor, and calculating the reference circle center of the processed part according to the position and change of the sampling data points is more accurate. However, the uniformly distributed sampling data points in this method may cause the fitting effect to be distorted, for example, when the clamping part deviates from the circle center, the corresponding obtained edge change will be more intense. At the same time, if the processed part has a non-smooth edge or its shape is irregular, the fitted edge after uniform sampling will cause the fitting effect to be poor, and the calculated reference circle center of the processed part will deviate. SUMMARY

[0004] In order to solve the above problems, the present application provides a workpiece processing reference circle center alignment method based on computer-aided calculation, which comprises:

[0005] Obtain the position information of all sampling points on the processed part before and after the sampling frequency adjustment, wherein the position information includes the laser distance of the sampling points;

[0006] Input the position information of all sampling points on the processed part into the coordinate system to obtain all sampling data points on the processed part; by analyzing the position distribution between each sampling data point and the adjacent sampling data point, the edge fluctuation degree of each sampling data point is obtained;

[0007] fitting the circular curve to all the sampling data points on the machining part to obtain a fitted circular curve; obtaining the variation difference of each sampling data point by analyzing the distribution of each sampling data point on the fitted circular curve; obtaining the frequency adjustment factor by adjusting the overlap between the fitted circular curves before and after the sampling frequency adjustment; obtaining the frequency adjustment weight according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points, and the frequency adjustment factor;

[0008] obtaining different sampling frequencies based on the frequency adjustment weight, and analyzing the variation between the center positions of the fitted circular curves under different sampling frequencies to obtain the reference center of the machining part.

[0009] Preferably, the method for obtaining the edge fluctuation degree of each sampling data point by analyzing the position distribution between each sampling data point and the adjacent sampling data point comprises the following specific method:

[0010] the interval formed between the i th sampling data point and the i+1 th sampling data point is denoted as the position interval of the i th sampling data point;

[0011] interpolating the position interval of the i th sampling data point by using the spline interpolation method to obtain the interpolated position interval of the i th sampling data point; and fitting the curve of all the data points in the interpolated position interval of the i th sampling data point to obtain the spline interpolation curve of the position interval of the i th sampling data point;

[0012] obtaining the distance difference value of each sampling data point according to the difference in laser distance between each sampling data point and the adjacent sampling data point;

[0013] obtaining the distance difference weight factor according to the distance difference value of the sampling data point;

[0014] the position interval of the i-1 th sampling data point and the position interval of the i+1 th sampling data point are both denoted as the adjacent interval of the position interval of the i th sampling data point;

[0015] obtaining the edge fluctuation factor of each adjacent interval of the position interval of the i th sampling data point according to the distance difference weight factor;

[0016] the cumulative sum of the edge fluctuation factors of all the adjacent intervals of the position interval of the i th sampling data point is taken as the edge fluctuation degree of the i th sampling data point.

[0017] Preferably, the method for obtaining the distance difference value of each sampling data point according to the difference in laser distance between each sampling data point and the adjacent sampling data point comprises the following specific method:

[0018] An absolute value of a difference between the laser distance of the i+1th sampling data point and the laser distance of the ith sampling data point is denoted as a distance difference value of the ith sampling data point.

[0019] Preferably, the method for obtaining the distance difference weight factor according to the distance difference value of the sampling data point comprises the following specific method:

[0020] An inverse proportional normalized value of an absolute value of a difference between the distance difference value of the ith sampling data point and the distance difference value of the i+1th sampling data point is denoted as the distance difference weight factor.

[0021] Preferably, the method for obtaining the edge fluctuation factor of each adjacent interval of the position interval of the ith sampling data point according to the distance difference weight factor comprises the following specific method:

[0022] For any one adjacent interval of the position interval of the ith sampling data point, an absolute value of a difference between a curvature of the spline interpolation curve of the position interval of the ith sampling data point and a curvature of the spline interpolation curve of the adjacent interval is denoted as a curvature difference value; an absolute value of a difference between an arc length of the spline interpolation curve of the position interval of the ith sampling data point and an arc length of the spline interpolation curve of the adjacent interval is denoted as a curvature difference value; a sum of the curvature difference value and the curvature difference value is denoted as a position distribution factor of the adjacent interval; a product of the position distribution factor of the adjacent interval and the distance difference weight factor is denoted as an edge fluctuation factor of the adjacent interval.

[0023] Preferably, the method for obtaining the variation difference of each sampling data point by analyzing a distribution of each sampling data point on the fitted circular curve comprises the following specific method:

[0024] A fitting circular curve overlap value of each sampling data point is obtained according to a distance between each sampling data point and the fitted circular curve.

[0025] A symmetric data point of each sampling data point is obtained.

[0026] For any one symmetric data point of the ith sampling data point, an absolute value of a difference between a circular curve overlap value of the any one symmetric data point and a circular curve overlap value of the ith sampling data point is denoted as a variation difference factor of the any one symmetric data point; an accumulated sum of the variation difference factors of all the symmetric data points of the ith sampling data point is taken as a variation difference of the ith sampling data point.

[0027] Preferably, the method for obtaining the fitting circular curve overlap value of each sampling data point according to the distance between each sampling data point and the fitted circular curve comprises the following specific method:

[0028] The shortest distance between the i-th sampling data point and the fitted circular curve is denoted as a first distance; the shortest distance between the i+1-th sampling data point and the fitted circular curve is denoted as a second distance; and the sum of the first distance and the second distance is taken as the fitted circular curve overlap value of the i-th sampling data point.

[0029] Preferably, the specific method for obtaining the symmetric data point of each sampling data point comprises:

[0030] In the rectangular coordinate system, the symmetric sampling data point of the horizontal coordinate of the center position of the fitted circular curve, the symmetric sampling data point of the vertical coordinate of the center position of the fitted circular curve, and the symmetric sampling data point of the center of the center position of the fitted circular curve are all denoted as the symmetric data point of the i-th sampling data point.

[0031] Preferably, the specific method for obtaining the frequency adjustment factor according to the overlap between the fitted circular curves before and after the sampling frequency adjustment comprises:

[0032] The distance between the center position of the fitted circular curve before the sampling frequency adjustment and the center position of the fitted circular curve after the sampling frequency adjustment is denoted as a center position adjustment factor;

[0033] The number of overlapping sampling data points between the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment is denoted as an overlap adjustment factor;

[0034] The product of the center position adjustment factor and the overlap adjustment factor is taken as the frequency adjustment factor.

[0035] Preferably, the specific method for obtaining the frequency adjustment weight according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points, and the frequency adjustment factor comprises:

[0036] The normalized value of the product of the mean value of the variation difference of all the sampling data points before the sampling frequency adjustment, the mean value of the edge fluctuation degree of all the sampling data points before the sampling frequency adjustment, and the frequency adjustment factor is taken as the frequency adjustment weight.

[0037] The beneficial effects of the technical scheme of the present application are: the present application performs circular curve fitting on all sampling data points on the machining part to obtain a fitted circular curve; the variation difference of each sampling data point is obtained by analyzing the distribution of each sampling data point on the fitted circular curve; the frequency adjustment factor is obtained by adjusting the overlap between the fitted circular curves before and after the sampling frequency; the frequency adjustment weight is obtained according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points and the frequency adjustment factor; different sampling frequencies are obtained based on the frequency adjustment weight, and the variation between the center positions of the fitted circular curves under different sampling frequencies is analyzed to obtain the reference center of the machining part; and the position of the obtained reference center of the machining part is more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0038] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor.

[0039] Figure 1 The step flow chart of the workpiece machining reference center alignment method based on computer aided calculation of the present application;

[0040] Figure 2 The feature relationship flow chart of the workpiece machining reference center alignment method based on computer aided calculation of the present application. DETAILED DESCRIPTION

[0041] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the workpiece machining reference center alignment method based on computer aided calculation according to the present application is described in detail below, including its specific implementation, structure, features and effects, combined with the drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures or characteristics in one or more embodiments can be combined in any suitable form.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0043] The specific scheme of the workpiece machining reference center alignment method based on computer aided calculation provided by the present application is described in detail below with reference to the drawings.

[0044] Please refer to Figure 1Fig. 1 shows a flow chart of a method for finding a center of a reference circle of a workpiece based on computer-aided calculation according to an embodiment of the present application, which comprises the following steps:

[0045] Step S001: Obtain position information of all sampling points on the workpiece before and after adjusting the sampling frequency, wherein the position information comprises laser distance of the sampling points.

[0046] It should be noted that in the clamping and rotating mode of the workpiece, the position information of the sampling points is obtained by the non-contact laser displacement sensor, and the sampling frequency of the workpiece is constantly adjusted, so that the position information of the sampling points can accurately quantify the edge information of the workpiece, and the least square method is used to determine the center of the reference circle.

[0047] Specifically, first, the position information of all sampling points on the workpiece is collected, and the specific process is as follows:

[0048] The workpiece is clamped and rotated, and a laser displacement sensor is installed on the side of the workpiece. The workpiece is rotated at a uniform speed, the sampling frequency of the laser displacement sensor before adjustment is set to 1 second, and the sampling frequency of the laser displacement sensor after adjustment is set to 0.5 second.

[0049] Each laser emitted by the laser displacement sensor to the edge position of the workpiece is recorded as a sampling point. The distance between each sampling point on the workpiece and the laser sensor is recorded as the laser distance of each sampling point. The laser distance and the rotation angle of each sampling point before and after adjusting the sampling frequency are recorded as the position information of each sampling point before and after adjusting the sampling frequency.

[0050] Thus, the position information of all sampling points on the workpiece before and after adjusting the sampling frequency is obtained by the above method.

[0051] Step S002: Input the position information of all sampling points on the workpiece into the coordinate system to obtain all sampling data points on the workpiece. The edge fluctuation degree of each sampling data point is obtained by analyzing the position distribution between each sampling data point and the adjacent sampling data point.

[0052] It should be noted that in the clamping and rotating mode of the machining part, when the clamping position is not on the symmetry axis of the machining part or deviates from the center of the circle, the rotation itself will also cause the distance change at different angles, so when analyzing the position information fluctuation of the sampling points, it needs to be considered that which fluctuation is caused by the real edge change of the machining part and which fluctuation is caused by the rotation of the sampling points; therefore, when analyzing the position information fluctuation of the sampling points, the position information of the obtained sampling points can be preliminarily processed, and the rotation angle and the distance of the obtained sampling points are coordinate-transformed into a rectangular coordinate system, so as to facilitate further geometric analysis and center calculation by using the least square method.

[0053] This embodiment is described by taking the sampling frequency adjustment before the lower as an example.

[0054] Preferably, in some implementation manners of the embodiment of the present application, the position information of all the sampling points on the machining part is input into the coordinate system, and the specific method for obtaining all the sampling data points on the machining part is as follows:

[0055] The clamping position of the machining part is taken as the center point of the polar coordinate system, and the polar coordinate system is constructed by using the position information of all the sampling points on the machining part, the polar coordinate system is converted into a rectangular coordinate system by using the conversion method of the polar coordinate, and then all the sampling data points on the machining part are obtained.

[0056] The construction of the polar coordinate system and the conversion method of the polar coordinate are prior art, and will not be described in detail herein.

[0057] Preferably, in some implementation manners of the embodiment of the present application, the specific method for obtaining the edge fluctuation degree of each sampling data point by analyzing the position distribution between each sampling data point and the adjacent sampling data point is as follows:

[0058] The interval formed between the i th sampling data point and the i+1 th sampling data point is recorded as the position interval of the i th sampling data point.

[0059] The absolute value of the difference between the laser distance of the i+1 th sampling data point and the laser distance of the i th sampling data point is recorded as the distance difference value of the i th sampling data point.

[0060] The position interval of the i th sampling data point is interpolated by using the spline interpolation method to obtain the interpolated position interval of the i th sampling data point; all the data points in the interpolated position interval of the i th sampling data point are curve-fitted to obtain the spline interpolation curve of the position interval of the i th sampling data point.

[0061] The spline interpolation method is prior art, and will not be described in detail herein.

[0062] The inverse proportional normalized value of the absolute value of the difference between the distance difference value of the i-th sampling data point and the distance difference value of the i+1-th sampling data point is denoted as a distance difference weight factor;

[0063] The position interval of the i-1-th sampling data point and the position interval of the i+1-th sampling data point are both denoted as a neighboring interval of the position interval of the i-th sampling data point; for any one neighboring interval of the position interval of the i-th sampling data point, the absolute value of the difference between the curvature of the spline interpolation curve of the position interval of the i-th sampling data point and the curvature of the spline interpolation curve of the neighboring interval is denoted as a curvature difference value; the absolute value of the difference between the arc length of the spline interpolation curve of the position interval of the i-th sampling data point and the arc length of the spline interpolation curve of the neighboring interval is denoted as a curvature difference value; the sum of the curvature difference value and the curvature difference value is denoted as a position distribution factor of the neighboring interval; the product of the position distribution factor of the neighboring interval and the distance difference weight factor is denoted as an edge fluctuation factor of the neighboring interval;

[0064] The cumulative sum of the edge fluctuation factors of all neighboring intervals of the position interval of the i-th sampling data point is taken as the edge fluctuation degree of the i-th sampling data point;

[0065] The specific formula is:

[0066]

[0067] In the formula, BL i denotes the edge fluctuation degree of the i-th sampling data point; n i denotes the number of all neighboring intervals of the position interval of the i-th sampling data point; ΔQl i,b denotes the absolute value of the difference between the curvature of the spline interpolation curve of the position interval of the i-th sampling data point and the curvature of the spline interpolation curve of the b-th neighboring interval thereof; ΔS i,b denotes the absolute value of the difference between the arc length of the spline interpolation curve of the position interval of the i-th sampling data point and the arc length of the spline interpolation curve of the b-th neighboring interval thereof; Δl i denotes the distance difference value of the i-th sampling data point; Δl i+1 denotes the distance difference value of the i+1-th sampling data point; ||denotes taking the absolute value; exp() denotes an exponential function with a natural constant as the base number; in the embodiment, an exp(-x) model is adopted to present an inverse proportional relationship and normalization processing, x is the input of the model, and the implementer can select an inverse proportional function and a normalization function according to actual conditions.

[0068] It should be noted that the difference between the distance difference values of the adjacent sampling data points obtained by calculation is taken as the weight, and the volatility is judged by analyzing the similarity between the arc composition in the position interval of the i-th sampling data point and its adjacent interval, so that the arc composition part of the position interval of the i-th sampling data point caused by its adjacent interval can be avoided to be dissimilar.

[0069] Up to now, the edge fluctuation degree of each sampling data point is obtained by the above method.

[0070] Step S003: fitting all the sampling data points on the machining part with a circular curve to obtain a fitted circular curve; obtaining the variation difference of each sampling data point by analyzing the distribution of each sampling data point on the fitted circular curve; obtaining the frequency adjustment factor by adjusting the overlap between the fitted circular curves before and after the sampling frequency; obtaining the frequency adjustment weight according to the variation difference of the sampling data point, the edge fluctuation degree of the sampling data point and the frequency adjustment factor.

[0071] It should be noted that when the edge fluctuation degree of the sampling data point is obtained, the sampling is adjusted by the positional relationship of the sampling data point, but the purpose of data collection in the embodiment is to fit the sampling data points with a circular curve, and the reference center is determined by constructing the fitting curve; therefore, the purpose of data sampling itself is to fit the circular curve, so when the data sampling is adjusted, the change of the fitting curve after the rotation speed is set can be analyzed, and the relationship of the sampling data points in the fitting curve is analyzed, and the sampling of each position is analyzed by the change of the fitting effect.

[0072] Preferably, all the sampling data points on the machining part are fitted with a circular curve to obtain a fitted circular curve;

[0073] Preferably, in some implementation manners of the embodiment of the application, the specific method for obtaining the variation difference of each sampling data point by analyzing the distribution of each sampling data point on the fitted circular curve is that:

[0074] The shortest distance between the i-th sampling data point and the fitted circular curve is denoted as the first distance; the shortest distance between the i+1-th sampling data point and the fitted circular curve is denoted as the second distance; and the sum of the first distance and the second distance is taken as the fitting circular curve overlap value of the i-th sampling data point.

[0075] Since the circle has symmetry, when the sampling adjustment is calculated, the variation difference of the sampling data point at the symmetrical position of the adjacent data point based on the fitted circular curve can be referred to, and the variation difference of each sampling data point is obtained; and the specific method is that:

[0076] In the rectangular coordinate system, the symmetric sampling data point of the i-th sampling data point with the horizontal coordinate of the center position of the fitted circular curve, the symmetric sampling data point of the i-th sampling data point with the vertical coordinate of the center position of the fitted circular curve, and the symmetric sampling data point of the i-th sampling data point with the center of the center position of the fitted circular curve are all recorded as the symmetric data point of the i-th sampling data point;

[0077] For any one of the symmetric data points of the i-th sampling data point, the absolute value of the difference between the circular curve overlap value of the any one of the symmetric data points and the circular curve overlap value of the i-th sampling data point is recorded as the change difference factor of the any one of the symmetric data points; and the cumulative sum of the change difference factors of all the symmetric data points of the i-th sampling data point is taken as the change difference of the i-th sampling data point.

[0078] The specific formula is:

[0079]

[0080] In the formula, BC i represents the change difference of the i-th sampling data point; D i represents all the symmetric data points of the i-th sampling data point; FG i represents the fitted circular curve overlap value of the i-th sampling data point; FG i,d represents the fitted circular curve overlap value of the d-th symmetric data point of the i-th sampling data point; and || represents taking the absolute value.

[0081] It should be noted that when the sampling points are obtained by clamping, the uniform sampling method will affect the fitting result of the circle, and the sampling points need to be appropriately increased for fitting a more accurate circular shape. Therefore, when fitting a circle, the distribution of the sampling points determines the quality of the fitting. If the sampling points are too concentrated in a certain area or are too sparse, the fitting result may have a large error, and even cannot correctly reflect the true geometric shape of the processed part. Since the sampling points need to uniformly cover the entire circular area, especially the points close to the circumference, to ensure that the center position of the circle can be accurately obtained during fitting, and when collecting data, the sampling density in a specific area of the part (such as the clamping part or the irregular area) needs to be increased to capture the edge information of these areas in more detail. Therefore, the frequency needs to be adjusted, and the obtained circular curve needs to be re-fitted for analyzing the fitting effect after adjusting the sampling multiple times, so that the center position of the processed part can be more accurately obtained.

[0082] Preferably, in some implementation manners of the embodiments of the present application, the specific method for obtaining the frequency adjustment factor according to the overlap between the fitted circular curves before and after the sampling frequency adjustment is as follows:

[0083] The distance between the center positions of the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment is recorded as a center position adjustment factor;

[0084] The number of overlapping sampling data points between the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment is recorded as an overlap adjustment factor;

[0085] The product of the center position adjustment factor and the overlap adjustment factor is taken as the frequency adjustment factor;

[0086] Preferably, in some implementations of the embodiments of the present application, the specific method for obtaining the frequency adjustment weight according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points, and the frequency adjustment factor is as follows:

[0087] The normalized value of the product of the mean of the variation difference of all the sampling data points before the sampling frequency adjustment, the mean of the edge fluctuation degree of all the sampling data points before the sampling frequency adjustment, and the frequency adjustment factor is taken as the frequency adjustment weight.

[0088] At this point, the frequency adjustment weight is obtained by the above method.

[0089] Step S004: Obtain different sampling frequencies based on the frequency adjustment weight, analyze the variation of the center positions of the fitted circular curves under different sampling frequencies, and obtain the reference center of the machining part.

[0090] It should be noted that after adjusting the sampling frequency, if there is no obvious change in the center positions of the fitted circular curves, it means that the current sampling adjustment has achieved good results, and there is no need to adjust the sampling data. Therefore, the center position of the fitted circular curve is taken as the reference center of the machining part.

[0091] Preferably, in some implementations of the embodiments of the present application, the specific method for obtaining the reference center of the machining part based on the frequency adjustment weight is as follows:

[0092] A reset parameter m is preset, and the present embodiment takes m=5 as an example for description, and the present embodiment is not specifically limited, wherein m is determined according to the specific implementation;

[0093] The product of the frequency adjustment weight and the adjusted frequency is taken as the next frequency adjustment value; the next frequency adjustment value is taken as the sampling frequency to obtain all the sampling data points on the machining part, and the circular fitting is performed on all the sampling data points on the machining part to obtain a new once-adjusted and fitted circular curve; based on the new once-adjusted and fitted circular curve, a new once-frequency adjustment value is obtained; and the above steps are repeated to obtain multiple adjusted and fitted circular curves; if the center positions of the continuous m once-adjusted and fitted circular curves are unchanged, the center position is taken as the reference center of the machining part.

[0094] Referring to Figure 2 which shows a feature relationship flowchart of a workpiece machining reference center alignment method based on computer-aided calculation;

[0095] Thus, the embodiment is completed.

[0096] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for finding the center of a workpiece machining reference circle based on computer-aided calculation, characterized in that, The method comprises the following steps: Obtaining position information of all sampling points on the machined part before and after sampling frequency adjustment, wherein the position information comprises laser distance of the sampling points; Inputting the position information of all sampling points on the machined part into a coordinate system to obtain all sampling data points on the machined part; obtaining edge fluctuation degree of each sampling data point by analyzing position distribution between each sampling data point and adjacent sampling data points; Fitting all sampling data points on the machined part with a circular curve to obtain a fitted circular curve; obtaining variation difference of each sampling data point by analyzing distribution of each sampling data point on the fitted circular curve; obtaining frequency adjustment factor according to overlapping condition between the fitted circular curves before and after sampling frequency adjustment; obtaining frequency adjustment weight according to the variation difference of the sampling data points, the edge fluctuation degree of the sampling data points and the frequency adjustment factor; Obtaining different sampling frequencies based on the frequency adjustment weight, analyzing variation condition between the centers of the fitted circular curves under different sampling frequencies, and obtaining the reference center of the machined part.

2. The computer-aided calculation-based workpiece machining reference circle center alignment method according to claim 1, characterized by, The method for obtaining the edge fluctuation degree of each sampling data point by analyzing the position distribution between each sampling data point and adjacent sampling data points comprises the following steps: An interval formed between the i th sampling data point and the i+1 th sampling data point is defined as a position interval of the i th sampling data point; An interpolation is performed on the position interval of the i th sampling data point by using a spline interpolation method to obtain an interpolated position interval of the i th sampling data point; a spline interpolation curve of the interpolated position interval of the i th sampling data point is obtained by fitting all data points in the interpolated position interval; A distance difference value of each sampling data point is obtained according to the difference in laser distance between each sampling data point and adjacent sampling data points; A distance difference weight factor is obtained according to the distance difference value of the sampling data point; Adjacent intervals of the position interval of the i th sampling data point are defined as the position interval of the i th sampling data point and the position interval of the i+1 th sampling data point; An edge fluctuation factor of each adjacent interval of the position interval of the i th sampling data point is obtained according to the distance difference weight factor; An accumulated sum of the edge fluctuation factors of all adjacent intervals of the position interval of the i th sampling data point is taken as the edge fluctuation degree of the i th sampling data point.

3. The computer-aided based workpiece machining reference circle center alignment method according to claim 2, wherein, The method for obtaining the distance difference value of each sampling data point according to the difference in laser distance between each sampling data point and adjacent sampling data points comprises the following steps: An absolute value of a difference value between the laser distance of the i+1 th sampling data point and the laser distance of the i th sampling data point is defined as the distance difference value of the i th sampling data point.

4. The computer-aided based workpiece machining reference circle center alignment method according to claim 2, wherein, The method for obtaining the distance difference weight factor according to the distance difference value of the sampling data point comprises the following steps: An inverse proportional normalized value of an absolute value of a difference value between the distance difference value of the i th sampling data point and the distance difference value of the i+1 th sampling data point is defined as the distance difference weight factor.

5. The computer-aided based workpiece machining reference circle center alignment method according to claim 2, wherein, The specific method for obtaining the edge fluctuation factor of each adjacent interval of the position interval of the i-th sampling data point according to the distance difference weight factor comprises the following steps: For any one adjacent interval of the position interval of the i-th sampling data point, the absolute value of the difference between the curvature of the spline interpolation curve of the position interval of the i-th sampling data point and the curvature of the spline interpolation curve of the adjacent interval is denoted as a curvature difference value; the absolute value of the difference between the arc length of the spline interpolation curve of the position interval of the i-th sampling data point and the arc length of the spline interpolation curve of the adjacent interval is denoted as a curvature difference value; the sum of the curvature difference value and the curvature difference value is denoted as a position distribution factor of the adjacent interval; the product of the position distribution factor of the adjacent interval and the distance difference weight factor is denoted as an edge fluctuation factor of the adjacent interval.

6. The computer-aided based workpiece machining reference circle center alignment method according to claim 1, wherein, The specific method for obtaining the variation difference of each sampling data point by analyzing the distribution of each sampling data point on the fitted circular curve comprises the following steps: According to the distance between each sampling data point and the fitted circular curve, a fitting circular curve overlap value of each sampling data point is obtained. Symmetrical data points of each sampling data point are obtained. For any one symmetrical data point of the i-th sampling data point, the absolute value of the difference between the circular curve overlap value of the any one symmetrical data point and the circular curve overlap value of the i-th sampling data point is denoted as a variation difference factor of the any one symmetrical data point; the cumulative sum of the variation difference factors of all symmetrical data points of the i-th sampling data point is taken as the variation difference of the i-th sampling data point.

7. The computer-aided based workpiece machining reference circle center alignment method of claim 6, wherein, The specific method for obtaining the fitting circular curve overlap value of each sampling data point according to the distance between each sampling data point and the fitted circular curve comprises the following steps: The shortest distance between the i-th sampling data point and the fitted circular curve is denoted as a first distance; the shortest distance between the i+1-th sampling data point and the fitted circular curve is denoted as a second distance; the sum of the first distance and the second distance is taken as the fitting circular curve overlap value of the i-th sampling data point.

8. The computer-aided based workpiece machining reference circle center alignment method of claim 6, wherein, The specific method for obtaining the symmetrical data points of each sampling data point comprises the following steps: In a rectangular coordinate system, the sampling data points symmetrical to the horizontal coordinate of the center position of the fitted circular curve, the sampling data points symmetrical to the vertical coordinate of the center position of the fitted circular curve, and the sampling data points symmetrical to the center of the center position of the fitted circular curve are all denoted as the symmetrical data points of the i-th sampling data point.

9. The computer-aided based workpiece machining reference circle center alignment method of claim 1, wherein, The specific method for obtaining the frequency adjustment factor according to the overlap between the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment comprises the following steps: The distance between the center positions of the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment is denoted as a center position adjustment factor; The number of overlapping sampling data points between the fitted circular curve before the sampling frequency adjustment and the fitted circular curve after the sampling frequency adjustment is denoted as an overlap adjustment factor; The product of the center position adjustment factor and the overlap adjustment factor is taken as the frequency adjustment factor.

10. The computer-aided based workpiece machining reference circle center alignment method of claim 1, wherein, The frequency adjustment weight is obtained according to the change difference of the sampling data points, the edge fluctuation degree of the sampling data points and the frequency adjustment factor, and the specific method comprises the following steps: The frequency adjustment weight is taken as the normalized value of the product of the mean value of the change difference of all the sampling data points before the sampling frequency adjustment, the mean value of the edge fluctuation degree of all the sampling data points before the sampling frequency adjustment and the frequency adjustment factor.

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