A method and device for detecting out-of-roundness of a cylinder pipe opening

Abstract

The present application relates to the technical field of pipe mouth contour measurement, and specifically to a method and device for detecting the out-of-roundness of a cylinder pipe mouth, the method comprising: obtaining out-of-roundness measurement data of each point on the cylinder pipe mouth; determining the distortion deformation of each point on the cylinder pipe mouth; determining the out-of-roundness difference value of each point on the cylinder pipe mouth based on the difference in the distortion deformation between each point on the cylinder pipe mouth and multiple neighboring points of its symmetrical point; determining the correction ratio of the out-of-roundness measurement data of each point on the cylinder pipe mouth; determining the correction value of the out-of-roundness measurement data of each point on the cylinder pipe mouth based on the difference in the out-of-roundness measurement data between each point on the cylinder pipe mouth and multiple neighboring points, and the correction ratio; determining the out-of-roundness of the cylinder pipe mouth based on the distribution of the correction value. The present application aims to improve the accuracy of the out-of-roundness detection result of the cylinder pipe mouth.

Description

Technical Field

[0001] The present application relates to the technical field of pipe orifice profile measurement, and in particular to a method and device for detecting the out-of-roundness of a pipe orifice of a cylinder pipe. Background Art

[0002] The cylinder tube is a high-precision steel tube material made by cold drawing or hot rolling. The cylinder tube is mainly used in hydraulic systems to convert hydraulic energy into mechanical energy. During the use of the cylinder tube, if the out-of-roundness of the cylinder tube mouth is too high, it will cause the seal to be incomplete, resulting in oil leakage. Oil leakage will not only reduce mechanical efficiency, but also may cause more serious mechanical failures and even safety accidents. Therefore, it is necessary to detect the out-of-roundness of the cylinder tube mouth.

[0003] Traditional technology generally uses laser ranging to detect the out-of-roundness of the cylinder tube mouth. However, due to the complex production environment of the cylinder tube, there is a lot of noise in the data collected by the laser, and the cylinder tube may be deformed, which leads to inaccurate positioning of the cylinder tube mouth center by the circle fitting method, resulting in inaccurate out-of-roundness detection results of the cylinder tube mouth. Summary of the invention

[0004] In view of the above, it is necessary to provide a method and device for detecting the out-of-roundness of a cylinder pipe orifice, which improves the accuracy of the out-of-roundness detection result of the cylinder pipe orifice compared with the traditional method for detecting the out-of-roundness of a cylinder pipe orifice:

[0005] In a first aspect, an embodiment of the present application provides a method for detecting the out-of-roundness of a cylinder pipe orifice, the method comprising the following steps:

[0006] The distance between each point on the nozzle of the oil cylinder pipe and the horizontal line perpendicular to the center of the rotating table is collected and recorded as the out-of-roundness measurement data of each point on the nozzle of the oil cylinder pipe;

[0007] Obtaining the average level of out-of-roundness measurement data of multiple neighboring points of each point on the nozzle of the oil cylinder pipe, and determining the distortion degree of each point on the nozzle of the oil cylinder pipe by comparing the average level of each point on the nozzle of the oil cylinder pipe with its neighboring points and combining the discrete degree of out-of-roundness measurement data of all points within the local range of each point;

[0008] Determine the out-of-roundness difference value of each point on the cylinder pipe orifice based on the difference in the degree of distortion between each point on the cylinder pipe orifice and a plurality of neighboring points of a symmetrical point;

[0009] Determine the correction ratio of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the out-of-roundness difference value and the degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe orifice;

[0010] Determining a correction value of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the difference between the out-of-roundness measurement data of each point on the cylinder pipe orifice and its multiple neighboring points, and the correction ratio;

[0011] Based on the distribution of the correction values, the out-of-roundness of the cylinder pipe opening is determined.

[0012] In one embodiment, the process of determining the distortion degree is as follows:

[0013] Calculate the average of the out-of-roundness measurement data of multiple neighboring points of each point on the cylinder pipe mouth;

[0014] Obtain the maximum value and the minimum value of the mean values ​​corresponding to two adjacent points on the nozzle of the oil cylinder pipe;

[0015] Determine the distribution value of each point on the nozzle of the oil cylinder pipe based on the mean value corresponding to each point on the nozzle of the oil cylinder pipe, as well as the maximum value and the minimum value;

[0016] The discrete degree of the out-of-roundness measurement data of each point on the cylinder pipe mouth and its multiple neighboring points is calculated, which is recorded as the overall discrete degree; the discrete degree of the out-of-roundness measurement data of multiple neighboring points of each point on the cylinder pipe mouth is calculated, which is recorded as the local discrete degree;

[0017] The difference between the overall discreteness and the local discreteness is recorded as discreteness difference;

[0018] The distortion degree is the product of the distribution value and the discrete difference.

[0019] In one embodiment, the method for determining the distribution value is: if the mean value corresponding to each point on the cylinder pipe orifice is less than or equal to the maximum value, and greater than or equal to the minimum value, then the distribution value of each point on the cylinder pipe orifice is taken as a first preset value; otherwise, the distribution value of each point on the cylinder pipe orifice is taken as a second preset value, and the second preset value is greater than the first preset value.

[0020] In one embodiment, the process of determining the out-of-roundness difference value is as follows:

[0021] Calculate the average value of the distortion of multiple neighboring points of each point on the cylinder pipe mouth, and record it as the distortion mean value;

[0022] The out-of-roundness difference value is the difference between the distortion deformation degree of each point on the cylinder pipe mouth and the distortion mean value corresponding to the symmetrical point thereof.

[0023] In one embodiment, the correction ratio is determined as follows:

[0024] The degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe mouth is recorded as the interference dispersion degree;

[0025] The correction ratio is positively correlated with the out-of-roundness difference value of each point on the pipe mouth of the oil cylinder pipe, and is negatively correlated with the interference discreteness.

[0026] In one embodiment, the correction value is determined as follows:

[0027] The average of the out-of-roundness measurement data of each point on the cylinder pipe mouth and its multiple neighboring points is recorded as the data mean;

[0028] Calculate the difference between the out-of-roundness measurement data of each point on the cylinder pipe mouth and the mean value of the data;

[0029] The product of the difference between each point on the oil cylinder pipe mouth and the correction ratio is recorded as the correction product;

[0030] The correction value is positively correlated with the out-of-roundness measurement data of each point on the pipe mouth of the oil cylinder pipe, and is negatively correlated with the correction product.

[0031] In one embodiment, the correction value is the difference between the out-of-roundness measurement data of each point on the cylinder pipe orifice and the correction product.

[0032] In one embodiment, the process of determining the out-of-roundness is:

[0033] Taking the center of the rotating table as the origin and the preset direction as the initial direction, rotating in the preset rotation direction, placing a point at every preset angle, and the Euclidean distance between the placed point and the origin is equal to the correction value;

[0034] Obtain the coordinates of each placement point, and perform circle fitting on the coordinates of all placement points;

[0035] Get the Euclidean distance from each placement point to the center of the fitting circle, recorded as the fitting distance;

[0036] Based on the maximum value and the minimum value of the fitting distance and the radius of the fitting circle, the out-of-roundness of the cylinder pipe opening is determined.

[0037] In one embodiment, the expression of the out-of-roundness is:

[0038] ; In the formula, Indicates the out-of-roundness of the cylinder pipe mouth; represents the radius of the fitted circle; represents the maximum value among the fitting distances; Represents the minimum value among the fitting distances.

[0039] In the second aspect, an embodiment of the present application also provides a device for detecting the out-of-roundness of a cylinder pipe orifice, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, the steps of any one of the above-mentioned methods for detecting the out-of-roundness of a cylinder pipe orifice are implemented.

[0040] This application has at least the following beneficial effects:

[0041] The present application obtains the average level of the out-of-roundness measurement data of multiple neighboring points of each point on the nozzle of the oil cylinder pipe, and determines the distortion deformation of each point on the nozzle of the oil cylinder pipe by comparing the average level of each point on the nozzle of the oil cylinder pipe and its neighboring points, and combining the discrete degree of the out-of-roundness measurement data of all points in the local range where each point is located, reflecting the possibility of distortion and deformation of each point on the nozzle of the oil cylinder pipe, and the possibility that the out-of-roundness measurement data of each point is affected by noise; and then based on the difference in the distortion deformation between each point on the nozzle of the oil cylinder pipe and multiple neighboring points of its symmetrical points, determines the out-of-roundness difference value of each point on the nozzle of the oil cylinder pipe, considers the symmetric characteristics of the distortion deformation of the ideal nozzle of the oil cylinder pipe, and further determines the possibility that the out-of-roundness measurement data of each point on the nozzle of the oil cylinder pipe is abnormal data by analyzing the distortion deformation at the symmetrical position on the nozzle of the oil cylinder pipe, and the abnormal data is the out-of-roundness measurement data at the position where the nozzle of the oil cylinder pipe is distorted, and the out-of-roundness measurement data affected by noise;

[0042] Furthermore, in order to solve the problem that the out-of-roundness difference value when the cylinder pipe mouth is twisted and deformed and the out-of-roundness difference value affected by noise are both large, and the out-of-roundness measurement data cannot be accurately corrected according to the influencing factors, the discrete degree of the out-of-roundness measurement data of the neighboring points of each point is used to obtain the degree of correction of the out-of-roundness measurement data of each point, and the distribution characteristics of the out-of-roundness difference values ​​caused by different influencing factors are fully considered. Then, the out-of-roundness measurement data is corrected according to the determined correction degree. The out-of-roundness measurement data affected by noise can be corrected to a greater extent, and the out-of-roundness measurement data of the cylinder pipe mouth that is twisted and deformed can be corrected to a smaller extent, so that the corrected value is closer to the true value, and then the center of the cylinder pipe mouth is obtained based on the corrected value, and the cylinder pipe mouth is detected for out-of-roundness, thereby improving the accuracy of the out-of-roundness detection of the cylinder pipe mouth. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 A flowchart of a method for detecting the out-of-roundness of a cylinder pipe orifice provided in accordance with an embodiment of the present application;

[0045] Figure 2 Schematic diagram of the measurement scene of the cylinder pipe mouth out of roundness Figure 1 ;

[0046] Figure 3 Schematic diagram of the measurement scene of the cylinder pipe mouth out of roundness Figure 2 ;

[0047] Figure 4 It is a schematic diagram of the distortion of each point on the pipe mouth of an ideal oil cylinder;

[0048] Figure 5 Schematic diagram of the correction value determination process. DETAILED DESCRIPTION

[0049] In the description of the embodiments of the present application, words such as "exemplary", "or", "for example" and the like are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "or", "for example" and the like is intended to present related concepts in a concrete manner.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the present application. The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. It should be understood that, unless otherwise specified, " / " means or.

[0051] It should also be noted that the terms "first" and "second" in the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0052] The following is a detailed description of a method and device for detecting the out-of-roundness of a cylinder pipe orifice provided by the present application in conjunction with the accompanying drawings.

[0053] See also Figure 1 , which shows a flowchart of a method for detecting the out-of-roundness of a cylinder pipe opening provided by an embodiment of the present application, the method comprising the following steps:

[0054] Step 1: Use a semiconductor laser to obtain out-of-roundness measurement data of each point on the nozzle of the oil cylinder pipe.

[0055] Schematic diagram of the measurement scene of the cylinder pipe mouth out of roundness Figure 1 like Figure 2 As shown, Figure 2 In the figure, 1 indicates the cylinder tube, 2 indicates the rotating table, 3 indicates the semiconductor laser, 4 indicates the rotating direction of the cylinder tube, O indicates the center of the rotating table, the cylinder tube is perpendicular to the rotating table, the rotating table makes the cylinder tube rotate, the rotating speed is 0.1r / s, that is, one rotation in 10 seconds, the semiconductor laser is placed on the side of the cylinder tube, the laser generated by the semiconductor laser is used to collect the distance between the semiconductor laser and each point on the cylinder tube mouth, recorded as the approach distance, the distance between each point on the cylinder tube mouth and the horizontal line perpendicular to the center of the rotating table is subtracted from the approach distance, the distance between each point on the cylinder tube mouth and the horizontal line perpendicular to the center of the rotating table is obtained, recorded as the out-of-roundness measurement data of each point on the cylinder tube mouth. Schematic diagram of the measurement scene of the out-of-roundness of the cylinder tube mouth Figure 2 like Figure 3 As shown, Figure 3 1 represents the oil cylinder tube, 2 represents the rotating table, 3 represents the semiconductor laser, O represents the center of the rotating table, A represents the point on the nozzle of the oil cylinder tube, L represents the horizontal line perpendicular to the center of the rotating table, d1 represents the distance between the semiconductor laser and the point A on the nozzle of the oil cylinder tube, that is, the approach distance, and d2 represents the distance between the point A on the nozzle of the oil cylinder tube and the horizontal line L perpendicular to the center of the rotating table. In the process of obtaining the approach distance using the semiconductor laser, the sampling frequency is 100Hz and the acquisition time is 10s. Among them, the rotation speed of 0.1r / s, the sampling frequency of 100Hz, and the acquisition time of 10s are only one embodiment of the present application. The values ​​of the rotation speed, sampling frequency and acquisition time are preset manually. When the values ​​of the rotation speed, sampling frequency and acquisition time can satisfy the semiconductor laser to collect the approach distance along the nozzle of the oil cylinder tube, the values ​​of the rotation speed, sampling frequency and acquisition time can be set by the implementer.

[0056] Step 2, obtaining the average level of out-of-roundness measurement data of multiple neighboring points of each point on the cylinder pipe mouth, and determining the distortion deformation of each point on the cylinder pipe mouth by comparing the average level of each point on the cylinder pipe mouth and its neighboring points, and combining the discrete degree of the out-of-roundness measurement data of all points within the local range of each point.

[0057] During the production process of the cylinder tube, cold drawing or hot rolling is required to make the cylinder tube present a hollow cylinder and the shape of the cylinder tube mouth is round. Due to the production shape of the cylinder tube, the surface of the cylinder tube is slightly deformed. In the most ideal case, the deformation of each position on the cylinder tube mouth is 0, but in actual cases, there is a difference in the deformation of different positions on the cylinder tube mouth, and the degree of deformation distortion in the local range of different positions is the same or similar.

[0058] Since the material of the oil cylinder pipe is alloy material, when distortion and deformation occur, the local characteristics of the out-of-roundness measurement data are single increase or single decrease. Therefore, the average of the out-of-roundness measurement data of multiple neighboring points of each point on the oil cylinder pipe mouth is calculated, and the maximum and minimum values ​​of the adjacent previous point and adjacent next point of each point on the oil cylinder pipe mouth corresponding to the average are obtained. Based on the out-of-roundness measurement data of each point on the oil cylinder pipe mouth and the maximum and minimum values, the distribution value of each point on the oil cylinder pipe mouth is determined. The expression is:

[0059] ; In the formula, Represents the distribution value of the i-th point on the cylinder pipe mouth; represents the mean value corresponding to the i-th point on the nozzle of the oil cylinder pipe; Indicates the minimum value of the mean corresponding to the adjacent previous point and the adjacent next point of the i-th point on the cylinder pipe mouth; Indicates the maximum value of the mean corresponding to the adjacent previous point and the adjacent next point of the i-th point on the oil cylinder pipe mouth; ω1 and ω2 both represent preset values ​​greater than 0, and ω2>ω1. The values ​​of ω1 and ω2 are preset by humans and can be set by the implementer. In this embodiment, the values ​​of ω1 and ω2 are 1 and 2 respectively; else indicates that except Except for the situation.

[0060] It should be noted that: for the position where the cylinder pipe mouth is twisted and deformed, the shape of this position has a certain curvature, so that the out-of-roundness measurement data in the twisted and deformed area is in a state of first increasing and then decreasing, or first decreasing and then increasing, with a trend of local single increase or single decrease. Therefore, the mean corresponding to the point in the twisted and deformed state should be greater than or equal to the minimum value of the means corresponding to the two adjacent points of the point, and less than or equal to the maximum value. At this time, the out-of-roundness measurement data of this point is more likely to be normal data or twisted and deformed data, and less likely to be caused by interference, and the distribution value of this point is smaller.

[0061] Further, based on the distribution value and the distribution of the out-of-roundness measurement data of each point on the cylinder pipe orifice and its multiple neighboring points, the distortion deformation degree of each point on the cylinder pipe orifice is determined, and the expression is:

[0062] ; In the formula, Indicates the distortion degree of the i-th point on the nozzle of the oil cylinder pipe; Represents the distribution value of the i-th point on the cylinder pipe mouth; Indicates the discrete degree of the out-of-roundness measurement data of the i-th point and its multiple neighboring points on the cylinder pipe mouth; It represents the discrete degree of the out-of-roundness measurement data of multiple neighboring points of the i-th point on the cylinder pipe mouth. Denote as the overall discrete degree, Denote as the local discrete degree, Recorded as discrete difference.

[0063] In this embodiment, in the process of calculating the distortion deformation of the i-th point on the nozzle of the oil cylinder pipe, the discrete degree involved is the mean absolute deviation. As other implementation methods, on the basis of measuring the uneven distribution of the out-of-roundness measurement data of the i-th point and its multiple neighboring points and the uneven distribution of the out-of-roundness measurement data of the i-th point's multiple neighboring points, the implementer can use other existing technologies for measurement, such as standard deviation, variance, etc., and this application does not make special restrictions. Among them, the calculation of the mean absolute deviation is a well-known technology and will not be repeated in this application.

[0064] It should be noted that: since the center of the cylinder pipe mouth cannot be directly determined during the measurement process, the discrete degree of the out-of-roundness measurement data of the i-th point and its multiple neighboring points at the normal cylinder pipe mouth without distortion is smaller than the discrete degree of the out-of-roundness measurement data of the i-th point's multiple neighboring points, which makes the distortion degree of the out-of-roundness measurement data The value of is smaller; in the process of out-of-roundness detection of the cylinder pipe mouth, the larger the value of the distortion deformation, the more likely the cylinder pipe mouth is to be distorted or the out-of-roundness measurement data is affected by noise, and the distortion deformation when the out-of-roundness measurement data is affected by noise is greater than the distortion deformation when the cylinder pipe mouth is distorted.

[0065] Step 3, determining the out-of-roundness difference value of each point on the cylinder pipe mouth based on the difference in the distortion between each point on the cylinder pipe mouth and a plurality of neighboring points of the symmetrical point.

[0066] Figure 4 It is a schematic diagram of the distortion degree of each point on the ideal cylinder pipe mouth. The ideal cylinder pipe mouth refers to the cylinder pipe mouth without distortion. Figure 4 The horizontal axis is the index of the point, and the vertical axis is the degree of distortion. If the measurement data collected by the semiconductor laser is not disturbed by noise, and the cylinder pipe mouth is not distorted, Figure 4 It can be seen that the distortion of all points on the cylinder pipe mouth has certain characteristics, that is, the distortion of the points in the first half is the same as that in the second half.

[0067] Therefore, the two symmetrical positions on the nozzle of the oil cylinder pipe should have the same state. When the nozzle of the oil cylinder pipe has a non-roundness problem, the non-roundness measurement data will have problems. Normally, the non-roundness measurement data is continuous, and the distortion should have a continuous difference. The continuous difference means that the distortion is smooth without sudden and large fluctuations. Therefore, when the distortion has a single fluctuation abnormality, that is, the distortion at any point is significantly different from that at other points, it means that the non-roundness measurement data at any point is affected by noise.

[0068] Based on the above analysis, based on the difference in the degree of distortion between each point on the cylinder pipe orifice and multiple neighboring points of its symmetrical point, the out-of-roundness difference value of each point on the cylinder pipe orifice is determined, and the expression is:

[0069] ; In the formula, It represents the out-of-roundness difference value of the i-th point on the nozzle of the oil cylinder pipe; Indicates the distortion degree of the i-th point on the nozzle of the oil cylinder pipe; , Respectively represent the first Point, The average value of the distortion of multiple neighboring points of a point; i represents the index of the point on the cylinder pipe mouth; n represents the number of points on the cylinder pipe mouth. , Recorded as Point, The distorted mean of the points.

[0070] It should be noted that: for the cylinder pipe mouth without distortion and no noise interference during data collection, the distortion of the points on the cylinder pipe mouth has a symmetrical feature, so that the distortion of each point on the cylinder pipe mouth is similar to the distortion of the points in the local area where the symmetrical point is located. When noise occurs, due to the discontinuous characteristics of noise, the distortion under noise interference is quite different from the distortion of the points in the local area where the symmetrical point is located. In addition, since the computer cannot identify which of the distortions of each point and its symmetrical point is interfered by noise, , When used as comparison data, only the Point, The distortion degree of multiple neighboring points of a point;

[0071] Therefore, without distortion and noise, or The value of is small and close to 0; when the out-of-roundness difference value of the i-th point on the cylinder pipe mouth is larger, it means that the out-of-roundness measurement data of the i-th point is more likely to be interfered by noise, resulting in a greater degree of distortion of the out-of-roundness measurement data. Therefore, the correction strength of the out-of-roundness measurement data of the i-th point should be greater, so that the out-of-roundness measurement data can return to the correct attribute and enhance the accuracy of the out-of-roundness measurement of the cylinder pipe mouth; when detecting the out-of-roundness of the cylinder pipe mouth, since the cylinder pipe mouth may be twisted and deformed, the difference between the twisted deformation position and its symmetrical position is greater than the difference between the twisted deformation position and its symmetrical position. Therefore, the out-of-roundness difference value of the twisted deformation position is also larger, which is greater than the out-of-roundness difference value of the normal position, but less than the out-of-roundness difference value when interfered by noise.

[0072] Step 4: determining a correction ratio of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the out-of-roundness difference value and the degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe orifice.

[0073] Since in the actual production process, all positions of the cylinder pipe orifices cannot be exactly the same, there are slight differences in the out-of-roundness difference values ​​at different points on the cylinder pipe orifices. However, when strong noise interference occurs, the out-of-roundness difference value affected by noise interference increases sharply, and the difference between the out-of-roundness difference value and the out-of-roundness difference value not affected by noise interference increases.

[0074] Based on the above analysis, based on the out-of-roundness difference value and the discrete degree of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe orifice, the correction ratio of the out-of-roundness measurement data of each point on the cylinder pipe orifice is determined, and the expression is:

[0075] ; In the formula, Indicates the correction ratio of the out-of-roundness measurement data of the i-th point on the cylinder pipe mouth; It represents the out-of-roundness difference value of the i-th point on the nozzle of the oil cylinder pipe; Indicates the degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of the i-th point on the cylinder pipe mouth; τ represents a value preset greater than 0, the purpose is to avoid the denominator being 0, the value of τ is preset manually, and the implementer can set it by himself. In this embodiment, the value of τ is 0.1, and Norm() represents the normalization function. It is recorded as the interference discreteness.

[0076] In this embodiment, the degree of dispersion of the out-of-roundness difference value is the standard deviation. As other implementation methods, on the basis of being able to measure the uneven distribution of the out-of-roundness difference value, the implementer may adopt other existing technologies for measurement, such as variance, coefficient of variation, etc., and this application does not impose any special restrictions.

[0077] In this embodiment, the Min-Max normalization method is used to Normalization is performed, as another implementation method, in which Based on the normalization process, implementers can use other existing technologies to Perform normalization processing, such as decimal calibration normalization method, Sigmoid function, etc., and this application does not make special restrictions.

[0078] It should be noted that: since the influence of noise on the out-of-roundness measurement data is greater than the influence of the distortion of the cylinder pipe nozzle on the out-of-roundness measurement data, when correcting the out-of-roundness measurement data, the degree of correction of the out-of-roundness measurement data affected by noise is greater than the degree of correction of the out-of-roundness measurement data when the cylinder pipe nozzle is distorted. However, the out-of-roundness difference value when the cylinder pipe nozzle is distorted is greater than the out-of-roundness difference value affected by noise. Therefore, the degree of correction of the out-of-roundness measurement data of each point is determined according to the discrete degree of the out-of-roundness difference values ​​of multiple neighboring points of each point. Smaller than the cylinder pipe mouth distortion Therefore, the correction ratio of the out-of-roundness measurement data affected by noise is greater than the correction ratio of the out-of-roundness measurement data caused by the distortion of the cylinder pipe mouth, thereby improving the accuracy of the out-of-roundness detection result of the cylinder pipe mouth.

[0079] Step 5: determining a correction value of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the difference in out-of-roundness measurement data between each point on the cylinder pipe orifice and its multiple neighboring points, and the correction ratio.

[0080] During the detection of the out-of-roundness of the cylinder pipe mouth, the out-of-roundness measurement data of the cylinder pipe mouth with distortion has changed, but there is an essential difference between the change caused by noise, so the correction ratio of the out-of-roundness measurement data in different situations is different.

[0081] Based on the above analysis, based on the difference in the out-of-roundness measurement data between each point on the cylinder pipe orifice and its multiple neighboring points, and the correction ratio, the correction value of the out-of-roundness measurement data of each point on the cylinder pipe orifice is determined, and the expression is:

[0082] ; In the formula, Indicates the correction value of the out-of-roundness measurement data of the i-th point on the nozzle of the oil cylinder pipe; Represents the out-of-roundness measurement data of the i-th point on the nozzle of the oil cylinder pipe; It represents the mean value of the out-of-roundness measurement data of the i-th point and its multiple neighboring points on the cylinder pipe mouth; Indicates the correction ratio of the out-of-roundness measurement data of the i-th point on the cylinder pipe mouth. Recorded as the data mean, Recorded as the corrected product.

[0083] It should be noted that: when the difference between the out-of-roundness measurement data of the i-th point on the cylinder pipe mouth and its neighboring points The larger the value is, the more likely it is that the out-of-roundness measurement data of the i-th point is noise data. The correction ratio of the out-of-roundness measurement data of the i-th point is The larger the value, the larger the correction value of the out-of-roundness measurement data. It is closer to the true value, making the out-of-roundness detection result of the cylinder pipe mouth more accurate. The flow chart of the correction value determination is as follows: Figure 5 shown.

[0084] Step 6: Determine the out-of-roundness of the cylinder pipe opening based on the distribution of the correction value.

[0085] According to the correction value of the out-of-roundness measurement data of all points on the nozzle of the oil cylinder pipe, the CAD software (Autodesk Computer Aided Design) is used to take the center of the rotating table as the origin, the preset direction as the initial direction, and rotate in the preset rotation direction, placing a point every 360 / 1000 degrees, so that the Euclidean distance between the origin and the i-th placement point is equal to the correction value of the i-th point on the nozzle of the oil cylinder pipe. The coordinates of each placement point are obtained, and the coordinates of all placement points are fitted with a circle, and the Euclidean distance from each placement point to the center of the fitting circle is obtained, recorded as the fitting distance, and the maximum and minimum values ​​in the fitting distance are counted. In this embodiment, the method for obtaining the fitting circle is the least squares method, which is a well-known technology and will not be repeated in this application. Among them, placing a point every 360 / 1000 degrees is calculated based on the rotation speed and sampling frequency in step 1.

[0086] In this embodiment, the preset direction is the horizontal direction, and the preset rotation direction is counterclockwise. The preset direction and the preset rotation direction are preset manually, and the implementer can also set them by himself. This application does not impose any special restrictions.

[0087] Based on the maximum value, the minimum value of the fitting distance, and the radius of the fitting circle, the out-of-roundness of the cylinder pipe mouth is determined, and the expression is:

[0088] ; In the formula, Indicates the out-of-roundness of the cylinder pipe mouth; represents the radius of the fitted circle; represents the maximum value among the fitting distances; Represents the minimum value among the fitting distances.

[0089] In this embodiment, the number of multiple neighboring points selected for each point is 12. The number of neighboring points is preset manually and can be set by the implementer. This application does not impose any special restrictions.

[0090] Based on the same inventive concept as the above method, an embodiment of the present application also provides a device for detecting the out-of-roundness of a cylinder pipe orifice, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned methods for detecting the out-of-roundness of a cylinder pipe orifice when executing the computer program.

[0091] In summary, the present application obtains the average level of out-of-roundness measurement data of multiple neighboring points of each point on the nozzle of the cylinder pipe, and determines the distortion of each point on the nozzle of the cylinder pipe by comparing the average level of each point on the nozzle of the cylinder pipe and its neighboring points, and combining the discrete degree of the out-of-roundness measurement data of all points in the local range where each point is located, reflecting the possibility of distortion at each point on the nozzle of the cylinder pipe, and the possibility that the out-of-roundness measurement data of each point is affected by noise; and then based on the difference in the distortion between each point on the nozzle of the cylinder pipe and multiple neighboring points of its symmetrical points, determines the out-of-roundness difference value of each point on the nozzle of the cylinder pipe, considers the symmetric characteristics of the distortion of the ideal nozzle of the cylinder pipe, and further determines the possibility that the out-of-roundness measurement data of each point on the nozzle of the cylinder pipe is abnormal data by analyzing the distortion at symmetrical positions on the nozzle of the cylinder pipe, i.e., the out-of-roundness measurement data at the position where the nozzle of the cylinder pipe is distorted, and the out-of-roundness measurement data affected by noise;

[0092] Furthermore, in order to solve the problem that the out-of-roundness difference value when the cylinder pipe mouth is twisted and deformed and the out-of-roundness difference value affected by noise are both large, and the out-of-roundness measurement data cannot be accurately corrected according to the influencing factors, the discrete degree of the out-of-roundness measurement data of the neighboring points of each point is used to obtain the degree of correction of the out-of-roundness measurement data of each point, and the distribution characteristics of the out-of-roundness difference values ​​caused by different influencing factors are fully considered. Then, the out-of-roundness measurement data is corrected according to the determined correction degree. The out-of-roundness measurement data affected by noise can be corrected to a greater extent, and the out-of-roundness measurement data of the cylinder pipe mouth that is twisted and deformed can be corrected to a smaller extent, so that the corrected value is closer to the true value, and then the center of the cylinder pipe mouth is obtained based on the corrected value, and the cylinder pipe mouth is detected for out-of-roundness, thereby improving the accuracy of the out-of-roundness detection of the cylinder pipe mouth.

[0093] The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

[0094] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, the above embodiments of the present application should be regarded as exemplary and non-restrictive.

Claims

1. A method for detecting the out-of-roundness of a cylinder pipe opening, characterized in that: The method comprises the following steps: The distance between each point on the nozzle of the oil cylinder pipe and the horizontal line perpendicular to the center of the rotating table is collected and recorded as the out-of-roundness measurement data of each point on the nozzle of the oil cylinder pipe; Obtaining the average level of out-of-roundness measurement data of multiple neighboring points of each point on the nozzle of the oil cylinder pipe, and determining the distortion degree of each point on the nozzle of the oil cylinder pipe by comparing the average level of each point on the nozzle of the oil cylinder pipe with its neighboring points and combining the discrete degree of out-of-roundness measurement data of all points within the local range of each point; Determine the out-of-roundness difference value of each point on the cylinder pipe orifice based on the difference in the degree of distortion between each point on the cylinder pipe orifice and a plurality of neighboring points of a symmetrical point; Determine the correction ratio of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the out-of-roundness difference value and the degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe orifice; Determining a correction value of the out-of-roundness measurement data of each point on the cylinder pipe orifice based on the difference between the out-of-roundness measurement data of each point on the cylinder pipe orifice and its multiple neighboring points, and the correction ratio; Determining the out-of-roundness of the cylinder pipe opening based on the distribution of the correction value; The process of determining the out-of-roundness is as follows: Taking the center of the rotating table as the origin and the preset direction as the initial direction, rotating in the preset rotation direction, placing a point at every preset angle, and the Euclidean distance between the placed point and the origin is equal to the correction value; Obtain the coordinates of each placement point, and perform circle fitting on the coordinates of all placement points; Get the Euclidean distance from each placement point to the center of the fitting circle, recorded as the fitting distance; Based on the maximum value and the minimum value of the fitting distance and the radius of the fitting circle, the out-of-roundness of the cylinder pipe opening is determined.

2. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 1, characterized in that: The process of determining the distortion degree is as follows: Calculate the average of the out-of-roundness measurement data of multiple neighboring points of each point on the cylinder pipe mouth; Obtain the maximum value and the minimum value of the mean values ​​corresponding to two adjacent points on the nozzle of the oil cylinder pipe; Determine the distribution value of each point on the nozzle of the oil cylinder pipe based on the mean value corresponding to each point on the nozzle of the oil cylinder pipe, as well as the maximum value and the minimum value; The discrete degree of the out-of-roundness measurement data of each point on the cylinder pipe mouth and its multiple neighboring points is calculated, which is recorded as the overall discrete degree; the discrete degree of the out-of-roundness measurement data of multiple neighboring points of each point on the cylinder pipe mouth is calculated, which is recorded as the local discrete degree; The difference between the overall discreteness and the local discreteness is recorded as discreteness difference; The distortion degree is the product of the distribution value and the discrete difference.

3. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 2, characterized in that: The method for determining the distribution value is: if the mean value corresponding to each point on the cylinder pipe orifice is less than or equal to the maximum value, and greater than or equal to the minimum value, then the distribution value of each point on the cylinder pipe orifice is taken as a first preset value; otherwise, the distribution value of each point on the cylinder pipe orifice is taken as a second preset value, and the second preset value is greater than the first preset value.

4. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 1, characterized in that: The process of determining the out-of-roundness difference value is as follows: Calculate the average value of the distortion of multiple neighboring points of each point on the cylinder pipe mouth, and record it as the distortion mean value; The out-of-roundness difference value is the difference between the distortion deformation degree of each point on the cylinder pipe mouth and the distortion mean value corresponding to the symmetrical point thereof.

5. The method for detecting the out-of-roundness of a cylinder pipe opening according to claim 1, characterized in that: The process of determining the correction ratio is as follows: The degree of dispersion of the out-of-roundness difference values ​​of multiple neighboring points of each point on the cylinder pipe mouth is recorded as the interference dispersion degree; The correction ratio is positively correlated with the out-of-roundness difference value of each point on the pipe mouth of the oil cylinder pipe, and is negatively correlated with the interference discreteness.

6. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 1, characterized in that: The process of determining the correction value is as follows: The average of the out-of-roundness measurement data of each point on the cylinder pipe mouth and its multiple neighboring points is recorded as the data mean; Calculate the difference between the out-of-roundness measurement data of each point on the cylinder pipe mouth and the mean value of the data; The product of the difference between each point on the oil cylinder pipe mouth and the correction ratio is recorded as the correction product; The correction value is positively correlated with the out-of-roundness measurement data of each point on the pipe mouth of the oil cylinder pipe, and is negatively correlated with the correction product.

7. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 6, characterized in that: The correction value is the difference between the out-of-roundness measurement data of each point on the cylinder pipe orifice and the correction product.

8. A method for detecting the out-of-roundness of a cylinder pipe opening as claimed in claim 1, characterized in that: The expression of the out-of-roundness is: ; In the formula, Indicates the out-of-roundness of the cylinder pipe mouth; represents the radius of the fitted circle; represents the maximum value among the fitting distances; Represents the minimum value among the fitting distances.

9. A device for detecting the out-of-roundness of a cylinder pipe orifice, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method for detecting the out-of-roundness of a cylinder pipe orifice as described in any one of claims 1 to 8 are implemented.

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