Gear measurement center rotating shaft error data processing method based on ball bar measurement

Abstract

The invention relates to a method for processing error data of a rotating shaft of a gear measurement center based on measurement of a ball bar. The method comprises the following steps: S1, data acquisition; s2, data preprocessing; s3, sphere center offset compensation is carried out; and S4, error fitting correction. According to the invention, by introducing the least square fitting and the polynomial fitting, the center-of-sphere offset error and the installation error in the measurement process of the ball bar instrument are effectively identified and compensated, so that the precision and the stability of geometric error data processing of the gear measurement center rotating shaft are improved; the problems of insufficient data preprocessing and poor error compensation effect in the prior art can be solved.

Description

Technical Field

[0001] This invention belongs to the field of error detection and relates to error data processing, and in particular to a method for processing error data of the rotating shaft of a gear measuring center based on ballbar measurement. Background Technology

[0002] The gear measuring center is a critical reference point in a mechanical transmission system, and the accuracy of its geometric parameters directly affects the gear's performance and service life. During gear rotation, geometric errors can lead to a decrease in transmission performance and even mechanical failure. Therefore, accurately measuring and analyzing the geometric errors of the gear measuring center is of paramount importance.

[0003] In existing technologies, the measurement and analysis of gear measurement centers mainly rely on various measurement methods and techniques. Among them, the ballbar, as a high-precision measuring tool, is widely used in the measurement of rotating shafts and gears. Through the ballbar trace function, three-dimensional coordinate data on rotating shafts or gears can be obtained, thereby further analyzing and calculating geometric errors.

[0004] However, existing technologies still have certain shortcomings in processing data collected by ballbar instruments: Insufficient data preprocessing: Existing technologies typically only perform basic outlier removal and coarse smoothing in the data preprocessing stage, lacking in-depth analysis and optimization of data quality, which affects the accuracy of subsequent analysis results; In terms of fitting the center coordinates of the circle and compensating for the ball center offset, existing technologies usually use simple methods, but when faced with complex workpieces or high-speed rotating shafts, the fitting effect is poor, resulting in insufficient compensation for measurement errors. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for processing error data of the rotating shaft of the gear measurement center based on ballbar measurement.

[0006] The technical problem solved by this invention is achieved through the following technical solution: A method for processing error data of the rotating shaft of a gear measurement center based on ballbar measurement, the method comprising the following steps: S1. Data Acquisition: Install the ball bar at different positions on the rotating axis according to the six-circle method and collect multiple sets of three-dimensional coordinate data; S2. Data preprocessing: Outlier removal and smoothing are performed on the multiple sets of three-dimensional coordinate data to obtain an effective dataset for fitting. S3, Sphere center offset compensation: The least squares fitting method is used to calculate the center coordinates and radius of each position in S1, and sphere center offset compensation is performed based on the difference in center coordinates. S4. Error Fitting Correction: The residual installation error is fitted and corrected based on a mathematical model of polynomial fitting.

[0007] Moreover, S1 specifically involves: using the ballbar trace function of the ballbar instrument and the G code setting of the gear measurement center, stopping the rotation axis of the gear measurement center for 1 second every 6° to collect data, and averaging the multiple sets of three-dimensional coordinate data collected at each position to the corresponding points.

[0008] Furthermore, S3 fits the center of the obtained ball bar instrument effective dataset to the circle using the least squares method, calculates the deviation between the center and the ideal center, and performs center offset compensation on all data.

[0009] Furthermore, S4 uses a polynomial mathematical model to fit the residual center coordinates after the sphere center offset compensation, and compensates for the installation error in the actual measurement data by correcting the residual error curve.

[0010] The advantages and beneficial effects of this invention are as follows: 1. This invention effectively identifies and compensates for ball center offset error and installation error in the ball bar measurement process by introducing least squares fitting and polynomial fitting, thereby improving the accuracy and stability of the geometric error data processing of the rotating shaft of the gear measurement center. It can solve the problems of insufficient data preprocessing and poor error compensation effect in the prior art.

[0011] 2. By averaging multiple sets of data during the measurement process and combining ball center offset compensation and error correction steps, this invention can also solve the errors that may occur in the measurement of complex workpieces and high-speed rotating shafts, obtain more accurate and reliable geometric error parameters of rotating shafts, and improve the overall performance of the measurement system. Attached Figure Description

[0012] Figure 1 This is a flowchart illustrating the present invention; Figure 2 This is a schematic diagram of the structure of the large-scale gear measuring center of the present invention; Figure 3 This is a schematic diagram of the six-circle method measurement of the ball bar instrument of the present invention; Figure 4 This is a schematic diagram illustrating the principle of the least squares method for handling center offset in this invention. Figure 5 This is a comparison chart of the ball bar instrument data before and after data processing according to the present invention. Detailed Implementation

[0013] The present invention will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present invention.

[0014] like Figure 1 As shown, a method for processing rotation axis error data of a gear measurement center based on ballbar measurement is innovative in that: the experimental object of this invention is a large-scale gear measurement center, such as... Figure 2 As shown, the process includes two steps: using the least squares method to handle the ball center offset error and using the polynomial fitting method to handle the ball bar installation error.

[0015] Specifically, the least squares method for handling ball bar center offset error first obtains the coordinates of each point from the measured data, then uses the least squares method to fit the center of each measurement circle, calculating the center coordinates and radius of each position. The fitted center offset value is then compensated for at each point, resulting in new measuring point coordinates and rod length changes. The polynomial fitting method for handling ball bar installation error involves fitting the center offset data to obtain the ball bar installation error. Substituting the data obtained after processing the installation error into the formula yields ten geometric errors of the gear measuring center rotation axis.

[0016] Specifically, the method for processing the error data of the rotating shaft of the gear measurement center based on ballbar measurement provided in this embodiment includes the following steps: (1) such as Figure 3 The diagram shows the operation of the six-circle method in different modes. The only difference between the different modes is the installation position. During operation, only the C-axis moves independently. The ballbar is installed according to the different modes of the six-circle method, and the corresponding G-code is written. When writing the G-code, it is ensured that the C-axis of the gear measurement center is paused once every 6 seconds. The ballbar trace function of the ballbar is used to perform measurements with a ballbar with a 150mm rod length, and the change in rod length at various points during operation is recorded. Source data such as Figure 5 As shown in (a).

[0017] (2) For each position, the multiple sets of data collected by the ball bar are averaged, as shown in the formula: ; in: i Representing different locations, n =60.

[0018] (3) Using the ballbar tool ball as the origin, establish a Cartesian coordinate system with the same coordinate axes as the gear measurement center. Since the ballbar operates in a two-dimensional plane, calculate the coordinates of each point based on the averaged data according to the angle, bar length, and bar length variation using the formula: ; (4) Figure 4The diagram illustrates the principle of center offset. The least squares fitting method is used to fit the center of the circle to the data from each measurement circle, calculating the center coordinates and radius at each location. The specific steps are as follows: 1. Perform circle fitting on the measurement data points at each location. Assume that the ballbar measurement data should ideally form a circle, with the equation of the circle as follows: ; in, o x , o y Let the coordinates be the center of the circle. r Let be the radius of the circle.

[0019] 2. The least squares method is used to fit the data, and the coordinates of the circle center and the radius are solved. The objective function of the least squares method is: ; 3. Calculate the center deviation at each position. Then, center offset compensation is performed on all data to obtain the compensated coordinate values ​​and the compensated change in rod length: ; After removing the ball bar center offset error, the data is as follows: Figure 5 As shown in (b).

[0020] (5) The installation error of the ballbar is much greater than the geometric error of the machine tool. Therefore, it is assumed that the radius deviation of the ballbar length itself is approximately circular and is caused by the installation error. That is, the constant term of the least squares fitting is caused by the installation error of the ballbar. Thus, the corresponding ballbar installation error and the corresponding ballbar data after removing the influence of the installation error are obtained by fitting. The installation error is corrected by using the polynomial fitting method. The specific steps are as follows: 1. Fit the compensated rod length change using a polynomial model: ; in: a i These are the parameters that need to be fitted.

[0021] 2. Based on the polynomial model fitting, the constant term is obtained as the installation error of the ballbar. Installation error compensation is then applied to all data. ; in, a 0 This is the error correction amount calculated through polynomial fitting. This is the data after processing.

[0022] After eliminating installation errors of the ball bar, the data is as follows: Figure 5As shown in (c).

[0023] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for processing error data of the rotating shaft of a gear measurement center based on ballbar measurement, characterized in that: The steps of the method are as follows: S1. Data Acquisition: Install the ball bar at different positions on the rotating axis according to the six-circle method and collect multiple sets of three-dimensional coordinate data; S2. Data preprocessing: Outlier removal and smoothing are performed on the multiple sets of three-dimensional coordinate data to obtain an effective dataset for fitting. S3, Sphere center offset compensation: The least squares fitting method is used to calculate the center coordinates and radius of each position in S1, and sphere center offset compensation is performed based on the difference in center coordinates. S4. Error Fitting Correction: The residual installation error is fitted and corrected based on a mathematical model of polynomial fitting.

2. The method for processing gear measurement center rotation axis error data based on ballbar measurement according to claim 1, characterized in that: Specifically, S1 involves: using the ballbar trace function of the ballbar instrument and the G code setting of the gear measurement center, stopping the rotation axis of the gear measurement center for 1 second every 6° to collect data, and averaging the multiple sets of three-dimensional coordinate data collected at each position to the corresponding points.

3. The method for processing gear measurement center rotation axis error data based on ballbar measurement according to claim 1, characterized in that: S3 uses the least squares method to fit the center of the ball bar instrument's effective dataset, calculates the deviation from the ideal center, and performs center offset compensation on all data.

4. The method for processing gear measurement center rotation axis error data based on ballbar measurement according to claim 1, characterized in that: The S4 method uses a polynomial mathematical model to fit the residual center coordinates after the sphere center offset compensation. By correcting the residual error curve, the installation error in the actual measurement data is compensated.

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