Sealed labyrinth chamfer arc radius measurement data processing method

Abstract

The invention discloses a sealing labyrinth chamfer arc radius measurement data processing method. The method comprises the following steps: S1, data segmentation: segmenting a data segment into a straight line segment and an elliptic arc by using a dichotomy in combination with a least square method; s2, data verification: scanning data by using a confocal sensor, irradiating the chamfer of the sealed labyrinth by using the confocal sensor, moving in a direction parallel to the display direction of the labyrinth, and measuring multiple groups of data in the process of moving from left to right; and S3, data processing: carrying out data cutting, noise reduction, clustering and fitting, and calculating parameters of an optimal fitting circle of the chamfer. The confocal sensor is used for scanning, so that the problems of light reflection and shielding are solved; the measuring method is good in consistency and high in precision, and solves the problem of improving the precision of measuring the chamfer arc radius of the sealing labyrinth.

Description

Technical Field

[0001] The invention relates to the field of sealing grate teeth, and in particular to a method for processing measurement data of a chamfered arc radius of a sealing grate teeth. Background Art

[0002] The sealing grate is a sealing device commonly used between the engine cylinder head and the engine body. Its main function is to prevent the leakage of engine oil, coolant and high-temperature gas to ensure the normal operation of the engine. The sealing grate is mainly composed of a metal frame and sealing materials. The sealing material is generally a high-temperature elastic material such as graphite, rubber, etc. The grate structure is as shown in the attached Figure 1 shown.

[0003] According to the manufacturing process requirements, it is necessary to ensure that Figure 2 The chamfers at the two circles shown are within the specified tolerance range. Due to the small chamfer radius, inclined angle, surrounding obstructions, small center angle and other factors, it is difficult to measure the chamfer radius using conventional means. Even if the measurement is barely possible, the accuracy is not high. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of how to improve the measurement accuracy of the chamfered arc radius of sealing grate teeth and to design a data processing method for measuring the chamfered arc radius of sealing grate teeth.

[0005] A method for processing measurement data of the chamfered arc radius of sealing grate teeth, comprising the following sub-steps: S1: Data segmentation: Use the binary method combined with the least squares method to segment the data segments into straight line segments and elliptical arcs; S2: Data verification: Use the confocal sensor to scan the data. Use the confocal sensor to illuminate the chamfer of the sealing grate teeth, move parallel to the direction of the grate teeth, and measure multiple sets of data during the movement from left to right; S3: Data processing: perform data cutting, noise reduction, clustering and fitting, and calculate the parameters of the best fitting circle of the chamfer.

[0006] Furthermore, a method for processing measurement data of the chamfer radius of the sealing grate teeth is provided, wherein step S1 comprises the following sub-steps: S11: Find the left boundary point of the straight line segment; S12: Find the right boundary point of the straight line segment; S13: Obtain data segmentation results.

[0007] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing comb teeth is provided, wherein step S11 comprises the following sub-steps: S111: Sort all points by horizontal axis, assuming the total number of data points is , the measured data is ; S112: Select an initial point P, assuming that the initial point P is the mth point, and ensure that P is located on the straight line segment; S113: Set variables As the starting point on the left side of the straight line segment, ensure , set the correlation coefficient is 0.999; S114: Point arrive Perform linear regression and calculate the equation of the line ; S115: Calculate the left correlation coefficient , the formula is: ; Said and Respectively represent The mean of S116: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat steps S214-S215; like , then the current The left boundary point of the straight line segment stops searching.

[0008] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing comb teeth, wherein step S12 comprises the following sub-steps: S121: Set variable As the end point on the right side of the straight line segment, ensure ; S122: Yes arrive Perform linear regression fitting and calculate the right correlation coefficient , the formula is: ; S123: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat step S222; like , then the current The search stops when the point is the right boundary of the line segment.

[0009] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing comb teeth, wherein step S13 comprises the following sub-steps: Elliptical arc: from the first point to the The first point is the first elliptical arc. Point to The points are the second elliptical arc; Straight line segment: From Point to Points are straight line segments.

[0010] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing grate teeth, wherein step S3 comprises the following sub-steps: S31: Data cutting and noise reduction: remove outliers and noise and retain valid point cloud data; S32: Data clustering: cluster the point cloud and divide the data into different areas; S32: Circle fitting: Split the data, calculate the axial magnification coefficient, convert the data into circle data, and use the least squares method to fit the circle; S33: Calculation of circle center and radius: The circle center and radius are obtained through optimization algorithm. The formula is: ; in, represents the coordinates of the center of the circle, is the circle radius.

[0011] The beneficial effects of the present invention include: a data processing method for measuring the chamfered arc radius of sealing grate teeth is adopted, a confocal sensor is used for scanning, and the reflection and occlusion problems are solved; the measurement method has good consistency and high precision, and the problem of improving the precision of measuring the chamfered arc radius of sealing grate teeth is solved; the data is cut, denoised, clustered and fitted to ensure the data accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram of the comb teeth structure.

[0013] Figure 2 This is the structural diagram of the chamfer of the comb teeth.

[0014] Figure 3 This is a set of chamfer data graphs from actual measurements.

[0015] Figure 4 This is the result diagram after data segmentation.

[0016] Figure 5 Scan data for the confocal sensor.

[0017] Figure 6 This is the ellipse fitting diagram.

[0018] Figure 7 This is the original data graph.

[0019] Figure 8 To split the data graph.

[0020] Fig. 9 A circular data graph.

[0021] Fig.10 This is a graph showing the effect of fitting the circular data. DETAILED DESCRIPTION

[0022] The present invention is further described below, but the protection scope of the present invention is not limited to the following description.

[0023] Theoretically, the measured data consists of circular arcs, straight line segments and circular arcs. However, due to the horizontal coordinate scaling, the actual data is a combination of elliptical arcs, straight line segments and elliptical arcs. The actual measured data is shown in the attached figure. Figure 3 shown.

[0024] A method for processing measurement data of the chamfered arc radius of sealing grate teeth, comprising the following sub-steps: S1: Data segmentation: Use the binary method combined with the least squares method to segment the data segments into straight line segments and elliptical arcs; As attached Figure 5 As shown, each line represents each measurement. S2: Data verification: Use the confocal sensor to scan the data. Use the confocal sensor to illuminate the chamfer of the sealing grate teeth, move parallel to the direction of the grate teeth, and measure multiple sets of data during the movement from left to right. S3: Data processing: perform data cutting, noise reduction, clustering and fitting, and calculate the parameters of the best fitting circle of the chamfer.

[0025] Furthermore, a method for processing measurement data of the chamfer radius of the sealing grate teeth is provided, wherein step S1 comprises the following sub-steps: S11: Find the left boundary point of the straight line segment; S12: Find the right boundary point of the straight line segment; S13: Obtain data segmentation results.

[0026] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing comb teeth is provided, wherein step S11 comprises the following sub-steps: S111: Sort all points by horizontal axis, assuming the total number of data points is , the measured data is ; S112: Select an initial point P, assuming that the initial point P is the mth point, and ensure that P is located on the straight line segment; S113: Set variables As the starting point on the left side of the straight line segment, ensure , set the correlation coefficient is 0.999; S114: Point arrive Perform linear regression and calculate the equation of the line ; S115: Calculate the left correlation coefficient , the formula is: ; Said and Respectively represent The mean of S116: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat steps S214-S215; like , then the current The left boundary point of the straight line segment stops searching.

[0027] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing comb teeth, wherein step S12 comprises the following sub-steps: S121: Set variable As the end point on the right side of the straight line segment, ensure ; S122: Yes arrive Perform linear regression fitting and calculate the right correlation coefficient , the formula is: ; S123: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat step S222; like , then the current The search stops when the point is the right boundary of the line segment.

[0028] As attached Figure 4 As shown, a method for processing measurement data of the chamfered arc radius of sealing grate teeth, the step S13 comprises the following sub-steps: Elliptical arc: from the first point to the The first point is the first elliptical arc. Point to The points are the second elliptical arc; Straight line segment: From Point to Points are straight line segments.

[0029] It should be noted that in the original image, the blue data points are the first segment of the elliptical arc, the green data points are the second segment of the elliptical arc, and the red points are the straight line segments. Now the horizontal line segments are used to replace the colors.

[0030] Furthermore, a method for processing measurement data of the chamfered arc radius of sealing grate teeth, wherein step S3 comprises the following sub-steps: S31: Data cutting and noise reduction: remove outliers and noise and retain valid point cloud data; S32: Data clustering: cluster the point cloud and divide the data into different areas; As attached Figure 6 As shown, S33: Calculation of the center and radius: The center and radius are obtained by the optimization algorithm, and the formula is: ; in, represents the coordinates of the center of the circle, is the circle radius.

[0031] Specific Example 1 Measurement Results and Accuracy Verification According to the point column data scanned by the sensor, the center and radius of the best fitting circle are calculated through data cutting, noise reduction, clustering, fitting and other algorithms. This verification completed the measurement of 9 comb tooth points of the part to be tested, and 2 chamfers at each point. The actual measurement data is shown in Table 1: Table 1 Real measurement data

[0032] According to the measurement data, the radius of the small circle meets the process requirements, while the radius of the large circle does not meet the process requirements of 1.2mm±0.2mm, but the measurement value of the large circle radius is relatively stable, all around 2.0mm, which can further verify its accuracy. By combining the comb tooth chamfer measurement data with the data obtained by measuring the gauge using the same method, it can be found that the measurement method has good consistency and high accuracy. The center angle of the circle is different due to different inclination angles each time and data processing, and there is no requirement in the process.

[0033] Specific Example 2 Measurement Data and Processing of 1mm Diameter Gauge As attached Figure 7-8 As shown in the figure, they are the original data and the data after segmentation, as shown in the attached Fig. 9 As shown in the figure, the data after segmentation is fitted with an ellipse, the axial magnification coefficient is calculated, and the data is converted into circular data, as shown in the figure. Fig.10 As shown, Figure 6 The effect diagram of circular data fitting, where r represents the radius in micrometers, d represents the central angle of the data, and note that the theoretical value of r is 500.

[0034] This solution adopts a data processing method for measuring the radius of the chamfered arc of the sealing grate teeth, and uses a confocal sensor for scanning to solve the problems of reflection and occlusion. The measurement method has good consistency and high accuracy, which solves the problem of improving the accuracy of measuring the radius of the chamfered arc of the sealing grate teeth. The data is cut, denoised, clustered and fitted to ensure data accuracy.

[0035] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for processing measurement data of the chamfer radius of sealing grate teeth, characterized in that: It includes the following sub-steps: S1: Data segmentation: Use the binary method combined with the least squares method to segment the data segments into straight line segments and elliptical arcs; S2: Data verification: Use the confocal sensor to scan the data. Use the confocal sensor to illuminate the chamfer of the sealing grate teeth, move parallel to the direction of the grate teeth, and measure multiple sets of data during the movement from left to right; S3: Data processing: perform data cutting, noise reduction, clustering and fitting, and calculate the parameters of the best fitting circle of the chamfer.

2. The method for measuring the radius of the chamfered arc of a sealing grate according to claim 1, characterized in that: The step S1 comprises the following sub-steps: S11: Find the left boundary point of the straight line segment; S12: Find the right boundary point of the straight line segment; S13: Obtain data segmentation results.

3. The method for measuring the radius of the chamfered arc of a sealing grate according to claim 2, characterized in that: The step S11 includes the following sub-steps: S111: Sort all points by horizontal axis, assuming the total number of data points is , the measured data is ; S112: Select an initial point P, assuming that the initial point P is the mth point, and ensure that P is located on the straight line segment; S113: Set variables As the starting point on the left side of the straight line segment, ensure , set the correlation coefficient is 0.999; S114: Point arrive Perform linear regression and calculate the equation of the line ; S115: Calculate the left correlation coefficient , the formula is: ； Said and Respectively represent The mean of S116: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat steps S214-S215; like , then the current The left boundary point of the straight line segment stops searching.

4. The method for processing measurement data of the chamfer radius of sealing grate teeth according to claim 3, characterized in that: The step S12 includes the following sub-steps: S121: Set variable As the end point on the right side of the straight line segment, ensure ; S122: Yes arrive Perform linear regression fitting and calculate the right correlation coefficient , the formula is: ； S123: Determine and adjust the starting point based on the correlation coefficient: like , then update for , repeat step S222; like , then the current The search stops when the point is the right boundary of the line segment.

5. The method for processing measurement data of the chamfer radius of sealing grate teeth according to claim 4, characterized in that: The step S13 includes the following sub-steps: Elliptical arc: from the first point to the The first point is the first elliptical arc. Point to The points are the second elliptical arc; Straight line segment: From Point to Points are straight line segments.

6. The method for processing measurement data of the chamfer radius of sealing grate teeth according to claim 1, characterized in that: The step S3 comprises the following sub-steps: S31: Data cutting and noise reduction: remove outliers and noise and retain valid point cloud data; S32: Data clustering: cluster the point cloud and divide the data into different areas; S32: Circle fitting: Split the data, calculate the axial magnification factor, convert the data into circle data, and use the least squares method to fit the circle; S33: Calculation of circle center and radius: The circle center and radius are obtained through optimization algorithm. The formula is: ； in, represents the coordinates of the center of the circle, is the circle radius.

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