CN114018202B - Novel algorithm for rapidly evaluating roundness - Google Patents
Novel algorithm for rapidly evaluating roundness Download PDFInfo
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- CN114018202B CN114018202B CN202111311769.1A CN202111311769A CN114018202B CN 114018202 B CN114018202 B CN 114018202B CN 202111311769 A CN202111311769 A CN 202111311769A CN 114018202 B CN114018202 B CN 114018202B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B21/00—Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
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Abstract
The invention discloses a novel algorithm for rapidly evaluating roundness, which comprises the following steps: s1, calculating the least square center coordinates and the least square roundness of the section outline of the tested rotating body by using a least square method; s2, picking up the point (x) with the section outline of the tested rotator furthest from the least square circle center max ，y max ) And the nearest point (x min ，y min ) The circle center is moved along the bisector l of the radius at the farthest point and the radius extension line at the nearest point according to a certain step length lambda, and the updated circle center and roundness are obtained; s3, repeating the step S2 according to the obtained updated circle center until the updated roundness is larger than the previous roundness value, and stopping moving; and S4, outputting the last roundness value, namely the final assessment result. The roundness evaluation method and the roundness evaluation device can obtain an enough and accurate evaluation result in a short time, and successfully solve the roundness evaluation problem.
Description
Technical Field
The invention relates to the technical field of roundness assessment of a revolving body, in particular to a novel algorithm for rapidly assessing roundness.
Background
In the field of mechanical manufacturing, rotating parts (such as shafts, discs, covers, holes, etc.) are of a large specific gravity, and the shape and position errors of the parts have a significant influence on the service performance of the parts. The roundness is one of the most common shape and position errors of rotary parts, and the detection and evaluation of the rotary parts are very important in actual production. This requires efficient detection and calculation methods to ensure an increase in production efficiency. The least square fitting technology is a common method for roundness evaluation, the calculation speed is high, but the roundness value obtained by calculation is exaggerated by about 10%, and the practicability is not strong in high-precision measurement. Numerous scholars in China have carried out a large number of researches on the minimum area assessment algorithm of roundness errors from different angles, and have proposed many optimization algorithms for assessing roundness errors, and representative algorithms are as follows: the increment-imitating algorithm, the searching algorithm, the calculation geometric algorithm, some other algorithms and the like have certain practical values, but most of the algorithms are complex and are not easy to be practically applied.
Disclosure of Invention
The invention aims to provide a novel algorithm for rapidly evaluating roundness, which can effectively obtain an adequately accurate evaluation result in a short time.
In order to achieve the above purpose, the present invention provides the following technical solutions: a new algorithm for rapid roundness assessment, comprising the steps of:
s1, calculating the least square center coordinates and the least square roundness of the section outline of the tested rotating body by using a least square method;
s2, picking up the point (x) with the section outline of the tested rotator furthest from the least square circle center max ，y max ) And the nearest point (x min ，y min ) The circle center is moved along the bisector l of the radius at the farthest point and the radius extension line at the nearest point according to a certain step length lambda, and the updated circle center and roundness are obtained;
s3, repeating the step S2 according to the obtained updated circle center until the updated roundness is larger than the previous roundness value, and stopping moving;
and S4, outputting the last roundness value, namely the final assessment result.
Preferably, in the step S2, the calculating process of updating the center of the circle is as follows:
firstly, calculating a direction vector of circle center movement according to the following formula:
re-calculating the coordinates (x) of the updated circle center 0 ， ，y 0 ， ）：
Wherein, (x) 0 ，y 0 ) For the updated circle center obtained last time, a is the x coordinate of l, and b is the y coordinate of l.
Preferably, the step size lambda is 10 -3 mm。
Compared with the prior art, the invention has the beneficial effects that: the invention determines the moving direction of the circle center through the least square circle center coordinates and the points farthest and nearest to the circle center coordinates, and finds the optimal circle center through the iteration of the circle center according to the movement of a certain step length, thereby obtaining a sufficiently accurate assessment result in a short time and successfully solving the roundness assessment problem.
Drawings
Fig. 1 is a schematic view of a roundness minimum area in the present invention.
FIG. 2 is a schematic diagram of a calculation process according to the present invention.
FIG. 3 is a schematic diagram of a calculation process according to the present invention.
FIG. 4 is a schematic diagram of a calculation flow of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further specifically described below by way of examples with reference to the accompanying drawings.
Examples: referring to fig. 1, a plurality of points corresponding to the cross-sectional profile of the revolution body are respectively concentric circles with the ideal circle center as the circle center and the distances from the ideal circle center to the farthest point and the nearest point as the radii, and the minimum area between the concentric circles is the target area with the minimum objective function value. Therefore, the roundness is the minimum target value obtained from the minimum region. Once the corresponding center is obtained, the objective function of roundness can be easily evaluated. Therefore, the computational efficiency depends on the speed at which the ideal center is determined. In order to build an efficient algorithm to find the ideal center of a circle, a series of mathematical models will be developed below.
Referring to fig. 2, let (x 1 ，y 1 ），（x 2 ，y 2 ），……（x i ，y i ），……（x n ，y n ) Representing the x and y coordinates of n points of the circle under test in the xy plane, the i-th point (x i ，y i ) Relative to an ideal center (x) 0 ，y 0 ) The radius of (2) is:
the maximum value of the radius values of the points corresponding to the ideal circle center is expressed as r max The minimum value is expressed as r min . The roundness h can then be expressed as:
according to the minimum area criterion, the center of the circle (x 0 ，y 0 ) Let h be the minimum. Then establishing a method for determining the center of the minimum area and evaluating the roundness h min Is shown below:
wherein r is max And r min The maximum and minimum radius values of the radius values of all the data points from the same center are respectively.
In order to minimize the roundness, the center of the circle is at the most distant point (x max ，y max ) And the nearest point (x min ，y min ) And (5) iteratively obtaining an updated circle center. The first circle center is obtained by least square methodThe circle center coordinates are multiplied to obtain the least square roundness (the least square method is used for calculating the least square circle center and the roundness in the prior art, and the embodiment is not described in detail). Picking up the point (x) with the longest distance from the least square center of the cross section outline of the tested rotator max ，y max ) And the nearest point (x min ，y min ) The center of the circle is moved along a radius external bisector l (i.e., a bisector of a radius at the farthest point and a radius extension line at the nearest point) corresponding to the least square center of the circle according to a certain step lambda, and an updated center of the circle and the roundness are obtained, as shown in fig. 3.
And repeating the steps according to the obtained updated circle center, specifically, picking up the point with the farthest distance and the nearest point according to the updated circle center, moving the circle center along the radius external bisector of the updated circle center corresponding to the two points according to a certain step length lambda, obtaining the updated circle center and the roundness until the updated roundness is larger than the last roundness value, namely, the difference between the front roundness and the rear roundness is smaller than 0, stopping iteration, and outputting the last roundness value, namely, the final assessment result.
Specifically, the center of the circle (x) is updated in the iterative process 0 ， ，y 0 ， ) The calculation process of (2) is as follows:
firstly, calculating a direction vector of circle center movement according to the following formula:
re-calculating the coordinates (x) of the updated circle center 0 ， ，y 0 ， ）：
Wherein, (x) 0 ，y 0 ) For the last obtained updated circle center, the step length lambda is 10 -3 mm, a is the x-coordinate of l and b is the y-coordinate of l.
The algorithm has the advantages that in roundness calculation, only an ideal circle center is needed to be searched, so that calculation is easy to encode, and enough precision can be obtained in a short time, and the detailed calculation flow is shown in fig. 4.
The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.
Claims (2)
1. A novel algorithm for rapid roundness assessment, comprising the steps of:
s1, calculating the least square center coordinates and the least square roundness of the section outline of the tested rotating body by using a least square method;
s2, picking up the point (x) with the section outline of the tested rotator furthest from the least square circle center max ，y max ) And the nearest point (x min ，y min ) The circle center is moved along the bisector l of the radius at the farthest point and the radius extension line at the nearest point according to a certain step length lambda, and the updated circle center and roundness are obtained;
the calculation process for updating the circle center is as follows:
firstly, calculating a direction vector of circle center movement according to the following formula:
re-calculating the coordinates (x) of the updated circle center 0 ， ，y 0 ， ）：
，
Wherein, (x) 0 ，y 0 ) For the updated circle center obtained last time, a is the x coordinate of l, and b is the y coordinate of l;
s3, repeating the step S2 according to the obtained updated circle center until the updated roundness is larger than the previous roundness value, and stopping moving;
and S4, outputting the last roundness value, namely the final assessment result.
2. A new algorithm for rapid roundness assessment according to claim 1, characterized in that said step λ is 10 - 3 mm。
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003322501A (en) * | 2002-04-30 | 2003-11-14 | Japan Atom Energy Res Inst | Roundness/straightness measuring system for duct |
| CN101373479A (en) * | 2008-09-27 | 2009-02-25 | 华中科技大学 | Method and system for searching computer picture of mammary gland x-ray radiography |
| CN101413793A (en) * | 2008-11-27 | 2009-04-22 | 天津大学 | Method for assessing composite space type face geometric error |
| CN106289145A (en) * | 2016-10-27 | 2017-01-04 | 北京理工大学 | A kind of cylindricity On-machine Test method |
| CN108871256A (en) * | 2018-06-13 | 2018-11-23 | 襄阳爱默思智能检测装备有限公司 | A kind of novel Circularity error evaluation algorithm |
| CN109780965A (en) * | 2019-01-29 | 2019-05-21 | 西安交通大学 | The more element detection devices in cylindrical surface and method based on concentric circles trellis traversal optimizing |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1978329A1 (en) * | 2007-04-04 | 2008-10-08 | Zumbach Electronic Ag | Method for measuring the roundness of round profiles |
| US11307015B2 (en) * | 2018-09-12 | 2022-04-19 | Dalian University Of Technology | Method for calculating eccentricity of rotor assembly axis based on radial runout measurement |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003322501A (en) * | 2002-04-30 | 2003-11-14 | Japan Atom Energy Res Inst | Roundness/straightness measuring system for duct |
| CN101373479A (en) * | 2008-09-27 | 2009-02-25 | 华中科技大学 | Method and system for searching computer picture of mammary gland x-ray radiography |
| CN101413793A (en) * | 2008-11-27 | 2009-04-22 | 天津大学 | Method for assessing composite space type face geometric error |
| CN106289145A (en) * | 2016-10-27 | 2017-01-04 | 北京理工大学 | A kind of cylindricity On-machine Test method |
| CN108871256A (en) * | 2018-06-13 | 2018-11-23 | 襄阳爱默思智能检测装备有限公司 | A kind of novel Circularity error evaluation algorithm |
| CN109780965A (en) * | 2019-01-29 | 2019-05-21 | 西安交通大学 | The more element detection devices in cylindrical surface and method based on concentric circles trellis traversal optimizing |
Non-Patent Citations (2)
| Title |
|---|
| 圆度误差的最小二乘法、最小包容区域法和最优函数法评定精度之比较;田树耀;;计量技术(07);全文 * |
| 基于VC的4种圆度误差评定方法的比较;张双双;杨洪涛;刘齐更;;工具技术(11);全文 * |
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