An axial positioning method, device and system for toroidal wave pattern parts

Abstract

The application relates to an axial positioning method, device and system for a ring wave part, and belongs to the technical field of fine micro-hole laser processing of ring wave parts. The method comprises the following steps: positioning a generatrix highest point and a generatrix lowest point of the ring wave part respectively; scanning the ring wave part along a first direction to obtain generatrix position information of the ring wave part; wherein the first direction is parallel to the direction of a connecting line between the generatrix highest point and the generatrix lowest point; performing reverse fitting according to the generatrix position information to obtain a generatrix contour of the ring wave part; and the generatrix contour of the ring wave part comprises a plurality of wave crests and a plurality of wave troughs on the generatrix contour of the ring wave part. The application performs reverse fitting on the generatrix of the ring wave part based on the scanning result, solves the influence of wave distance deviation of the ring wave part caused by local deformation on positioning accuracy and machining accuracy, and guarantees positioning accuracy and part machining quality.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fine micro-hole laser processing of ring wave-shaped parts, and particularly relates to an axial positioning method, device and system for ring wave-shaped parts. BACKGROUND

[0002] As one of the most advanced processing and manufacturing technologies, laser processing technology has the advantages of high precision, high controllability and high efficiency, and can solve the processing problems of cutting of difficult-to-machine materials, efficient processing of group holes of large thin-walled parts, high-precision cutting of part air film holes, and three-dimensional complex curved surface etching in special mechanical manufacturing.

[0003] In the processing of conventional cylindrical parts, the top surface or the bottom surface is usually selected as the reference. However, compared with conventional parts, the tube wall of the ring wave-shaped part is extremely thin and is prone to deformation, which affects the positioning accuracy. In addition, the poor machining quality and position accuracy of the hole position of the ring wave-shaped part seriously affect the performance and quality of the overall part. In addition, due to the extremely large number of holes machined on the ring wave-shaped part, it is difficult to ensure the hole positioning accuracy in the case of large overall roundness, large wave height or large wave distance deviation.

[0004] At present, in the hole making process of the ring wave-shaped part, one positioning method is to manually adjust based on the reference point or feature point on the clamp, but this method completely depends on the experience of the operator, and the positioning accuracy of the complex curved surface part which is difficult to determine the feature point itself is poor. In addition, positioning by feature points can only meet the positioning requirements of one position degree, without considering the error caused by the deformation of the part itself, the consistency of positioning accuracy and machining angle is also poor, and the efficiency is also low. Another positioning method needs to prepare a special tooling fixture to reduce the deformation of the workpiece, and then process based on computer aided manufacturing software. This method depends on a special tooling fixture, and the design and manufacturing cost is high. Whether it is a tooling fixture or a computer aided manufacturing software, it is difficult to handle the actual local deformation, and finally it is still difficult to ensure the positioning accuracy and part processing quality. Therefore, a method and system for improving the axial positioning accuracy of the ring wave-shaped part are needed. SUMMARY

[0005] In order to solve the above problems existing in the prior art, the application provides an axial positioning method and system for a ring wave-shaped part. The technical problem to be solved by the application is solved by the following technical scheme:

[0006] The application provides an axial positioning method for a ring wave-shaped part, comprising:

[0007] Positioning the highest point and the lowest point of the generatrix of the ring wave-shaped part, respectively;

[0008] Scanning the ring wave-shaped part along a first direction to obtain busbar position information of the ring wave-shaped part; the first direction is parallel to a direction of a line between the busbar highest point and the busbar lowest point;

[0009] Reversely fitting according to the busbar position information to obtain a busbar profile of the ring wave-shaped part; the busbar profile of the ring wave-shaped part includes a plurality of wave crests and a plurality of wave troughs on the busbar profile of the ring wave-shaped part.

[0010] In an embodiment of the present application, respectively positioning the busbar highest point and the busbar lowest point of the ring wave-shaped part includes:

[0011] Fixing the ring wave-shaped part on a horizontal workbench;

[0012] Setting the busbar highest point as a first measurement point and respectively measuring positions of the first measurement point along a second direction and along a third direction to position the busbar highest point of the ring wave-shaped part; wherein the second direction is along a surface normal direction of the ring wave-shaped part and the third direction is along an axial direction of the ring wave-shaped part;

[0013] Setting the busbar lowest point as a second measurement point and respectively measuring positions of the second measurement point along the second direction and along the third direction to position the busbar lowest point of the ring wave-shaped part.

[0014] In an embodiment of the present application, reversely fitting according to the busbar position information to obtain the busbar profile of the ring wave-shaped part includes:

[0015] According to the busbar position information, adopting a B-spline curve fitting method to obtain a B-spline curve of the busbar of the ring wave-shaped part;

[0016] According to the B-spline curve of the busbar of the ring wave-shaped part, adopting a second-order difference identification algorithm to obtain the busbar profile of the ring wave-shaped part.

[0017] In an embodiment of the present application, according to the busbar position information, adopting the B-spline curve fitting method to obtain the B-spline curve of the ring wave-shaped part includes:

[0018] Respectively setting a degree, a control point distribution region, a weight value and a node of the B-spline curve and generating a plurality of expected profile points according to the busbar position information;

[0019] Respectively setting a maximum distance and a maximum error of the B-spline curve and obtaining the B-spline curve of the ring wave-shaped part according to the plurality of expected profile points.

[0020] In an embodiment of the present application, an expression of the B-spline curve is:

[0021]

[0022] wherein C(u) is a parametric equation of the B-spline curve; P i is the i th control point; N i,p (u) is a base function of the i th p-degree B-spline curve of the i th control point; i is a first ordinal parameter; p is a degree parameter; u is a control point on the B-spline curve; and n is a total number of control points.

[0023] In an embodiment of the present application, the expression of the base function of the B-spline curve is:

[0024]

[0025] wherein N i,0 (u) is a base function of the i th 0-degree B-spline curve of the i th control point; u i is the i th control point on the B-spline curve.

[0026] In an embodiment of the present application, according to the B-spline curve of the generatrix of the ring-shaped wave-shaped part, a second-order difference identification algorithm is used to obtain the generatrix profile of the ring-shaped wave-shaped part, comprising:

[0027] According to the B-spline curve of the generatrix of the ring-shaped wave-shaped part, convolution calculation is performed based on a second-order difference operator, and feature extraction is performed to obtain edges and feature points on the B-spline curve;

[0028] According to the edge curvature and the feature points, the generatrix profile of the ring-shaped wave-shaped part is obtained; wherein the generatrix profile of the ring-shaped wave-shaped part includes a plurality of convex points and concave points, the convex points are wave peak positions on the generatrix profile of the ring-shaped wave-shaped part, and the concave points are wave valley positions on the generatrix profile of the ring-shaped wave-shaped part.

[0029] In an embodiment of the present application, the expression of the second-order difference identification algorithm is:

[0030] f''(j) = f(j+1) - 2f(j) + f(j-1);

[0031]

[0032] wherein f(j) is a gray value of the j th point on the B-spline curve; j is a first ordinal parameter; f''(j) is a second-order difference discrete function of f(j); is a second-order difference operator; x is a first parameter; and y is a second parameter; is a partial derivative function.

[0033] The present application also provides an axial positioning device for a ring-shaped wave-shaped part, which uses the above-mentioned axial positioning method for a ring-shaped wave-shaped part, and the axial positioning device comprises a distance measuring module and a data acquisition and processing module.

[0034] The ranging module is used for positioning the generatrix highest point and the generatrix lowest point of the ring wave-shaped part respectively, and scanning the ring wave-shaped part along a first direction to obtain the generatrix position information of the ring wave-shaped part.

[0035] The data acquisition and processing module is used for performing reverse fitting according to the generatrix position information to obtain the generatrix contour of the ring wave-shaped part.

[0036] The application further provides an axial positioning system for a ring wave-shaped part, which comprises a machining tool and the axial positioning device for the ring wave-shaped part.

[0037] The ranging module is arranged on the movement module of the machining tool and moves with the movement module of the machining tool to obtain the generatrix position information of the ring wave-shaped part in real time through movement scanning.

[0038] Compared with the prior art, the axial positioning method for the ring wave-shaped part has the following beneficial effects:

[0039] The axial positioning method for the ring wave-shaped part is based on simple scanning to obtain the generatrix position information of a complex workpiece such as the ring wave-shaped part, and then based on the scanning result to perform reverse fitting on the generatrix of the ring wave-shaped part, thereby obtaining the wave peak and the wave trough after deformation of the ring wave-shaped part through fitting of the contour after deformation of the ring wave-shaped part, and solving the influence of the wave distance deviation of the ring wave-shaped part caused by local deformation on the positioning accuracy and the machining accuracy, and ensuring the positioning accuracy and the machining quality of the part.

[0040] The above description is only a summary of the technical scheme of the application, in order to more clearly understand the technical means of the application, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a structure schematic view of an existing ring wave-shaped part;

[0042] Figure 2 is a structure front view of an existing ring wave-shaped part;

[0043] Figure 3 is a schematic view of the error between the theoretical position and the actual position caused by local deformation;

[0044] Figure 4 is a flowchart of an axial positioning method for a ring wave-shaped part provided by an embodiment of the application;

[0045] Figure 5 is a flowchart of step 1 of the axial positioning method for the ring wave-shaped part provided by an embodiment of the application;

[0046] Figure 6 is a flow chart of step 3 of the axial positioning method for the annular wave-shaped part provided by the embodiment of the present application;

[0047] Figure 7 is a flow chart of step 3.1 of the axial positioning method for the annular wave-shaped part provided by the embodiment of the present application;

[0048] Figure 8 is a flow chart of step 3.2 of the axial positioning method for the annular wave-shaped part provided by the embodiment of the present application;

[0049] Figure 9a is a schematic diagram of the B-spline curve obtained by automatic fitting provided by the embodiment of the present application;

[0050] Figure 9b is a schematic diagram of the B-spline curve obtained by manual fitting provided by the embodiment of the present application;

[0051] Figure 9c is a deviation schematic diagram of the B-spline curve obtained by automatic fitting provided by the embodiment of the present application;

[0052] Figure 9d is a deviation schematic diagram of the B-spline curve obtained by manual fitting provided by the embodiment of the present application;

[0053] Figure 10 is a generatrix contour schematic diagram of the annular wave-shaped part obtained by using the positioning method and the positioning system provided by the embodiment of the present application;

[0054] Figure 11 is a structural block diagram of an axial positioning system for the annular wave-shaped part provided by the embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to further illustrate the technical means and effects taken by the present application to achieve the predetermined purposes, the axial positioning method, device and system for the annular wave-shaped part according to the present application are described in detail below in combination with the drawings and specific embodiments.

[0056] The foregoing and other technical contents, features and effects of the present application can be clearly presented in the detailed description of the specific embodiments below in combination with the drawings. Through the description of the specific embodiments, the technical means and effects taken by the present application to achieve the predetermined purposes can be understood more deeply and specifically. However, the attached drawings are provided for reference and illustration only, and are not used to limit the technical solutions of the present application.

[0057] Embodiment One

[0058] As Figure 1 andFigure 2 As shown in the figure, the annular corrugated part is usually a thin-walled cylindrical part, which is composed of several corrugated circular rings connected in sequence. There are crests and troughs between two adjacent corrugated circular rings. When the holes are processed on the annular corrugated part along the axial direction, the deviation between the crests and troughs and the wave distance of the corrugated circular rings, or the local deformation of the annular corrugated part itself, can easily lead to inaccurate positioning, resulting in a deviation between the actual positioning position and the theoretical position, such as Figure 3 As shown, it further affects the processing accuracy during the hole making process.

[0059] In view of this, if Figure 4 As shown, the first aspect of the present invention provides an axial positioning method for an annular corrugated part, comprising the steps of:

[0060] Step 1: Locate the highest point and the lowest point of the busbar of the annular wave-shaped part respectively.

[0061] like Figure 5 As shown, in this embodiment, step 1 includes:

[0062] Step 1.1: Fix the ring-shaped corrugated part on a horizontal workbench;

[0063] Step 1.2: Set the highest point of the generatrix as the first measurement point, and measure the positions of the first measurement point along the second direction and the third direction to locate the highest point of the generatrix of the annular corrugated component. The second direction is the surface normal direction of the annular corrugated component, and the third direction is the axial direction of the annular corrugated component.

[0064] Step 1.3: Set the lowest point of the busbar as the second measuring point, and measure the positions of the second measuring point along the second direction and along the third direction respectively to locate the lowest point of the busbar of the annular corrugated part.

[0065] Specifically, the position information of the highest point and the lowest point of the busbar of the annular corrugated part is obtained by measurement, that is, the position of the highest point and the lowest point of the busbar along the surface normal direction and the axial direction of the annular corrugated part.

[0066] Step 2: Scan the annular wave-shaped part along a first direction to obtain the busbar position information of the annular wave-shaped part; the first direction is parallel to the direction of the line connecting the highest point of the busbar and the lowest point of the busbar.

[0067] Specifically, scanning is performed at a uniform speed along the first direction, moving from the highest point of the busbar of the annular wave-shaped part to the lowest point of the busbar, or moving from the lowest point of the busbar of the annular wave-shaped part to the highest point of the busbar, and the scanning results are collected in real time during the scanning process to obtain the busbar position information of the annular wave-shaped part.

[0068] Step 3: reverse fitting according to the generatrix position information to obtain the generatrix profile of the ring wave type part; the generatrix profile of the ring wave type part includes a plurality of wave crests and a plurality of wave troughs on the generatrix profile of the ring wave type part.

[0069] As shown in the embodiment, step 3 includes: Figure 6

[0070] Step 3.1: according to the generatrix position information, a B-spline curve fitting method is used to obtain the B-spline curve of the generatrix of the ring wave type part.

[0071] As shown in the embodiment, step 3.1 includes: Figure 7

[0072] Step 3.1.1: respectively set the order of the B-spline curve, the control point distribution area, the weight value and the node, and generate a plurality of expected profile points according to the generatrix position information.

[0073] Specifically, the order of the B-spline curve determines the smoothness of the generated curve, and the entire curve is located within the range of its control points, and the control point distribution area is similar to a framework that wraps the curve. The weight value determines the degree to which the generated curve is attracted to the control point, and the node determines the distribution method of the curve.

[0074] Optionally, the generatrix position information can be automatically fitted based on an external processing device. When automatically fitting, since the weights of all control points are the same, the attraction of all control points to the curve remains consistent. The node can also be set based on automatic fitting, which can enhance flexibility, improve fitting accuracy and simplify operation. The weight value can also be set based on automatic fitting to adapt to the differences in generatrix position information and to adapt to the accuracy requirements. At the same time, the generatrix position information can also be manually fitted based on manual setting, which is more conducive to improving fitting accuracy and flexibility, but may also increase the complexity of setting and require more time for adjustment. As shown in Figure 9a and Figure 9b As shown in Figure 9c and Figure 9d As shown in

[0075] Step 3.1.2: respectively set the maximum distance and the maximum error of the B-spline curve, and obtain the B-spline curve of the ring wave type part according to the plurality of expected profile points.

[0076] ​​Specifically, to improve the accuracy of the B-spline curve, the maximum distance and the maximum error also need to be considered. The maximum distance refers to the maximum distance between two expected contour points, which specifies the accuracy of the curve fitting. A smaller value will make the generated curve fit the original contour more accurately, but may increase the computational complexity and time. A larger value will produce a more simplified curve, but may lose some details. The maximum error refers to the maximum distance between the expected contour points and the actually generated B-spline curve. It is mainly used to control the distance between the curve and the expected contour points. The smaller this value is, the smaller the distance between the generated curve and the original contour is, and the better the fitting effect is, which helps to avoid the curve deviating from the original contour too far. By setting the maximum distance and the maximum error, the approximation degree of the B-spline curve can be further optimized while maintaining the overall shape of the B-spline curve. The lower the maximum distance and the maximum error are, the better the approximation of the curve is, and at this time, all expected contour points should be accurately located on the curve.

[0077] In addition, one of the maximum distance and the maximum error can also be ignored. When the maximum distance is ignored, the shape of the fitted curve depends on the original data, which is suitable for application scenarios with high overall shape requirements. When the maximum error is ignored, although the accuracy is sacrificed, the fitting speed is significantly improved, which is suitable for situations where the fitting speed is required.

[0078] In an optional embodiment, the expression of the B-spline curve is:

[0079]

[0080] where C(u) is the parametric equation of the B-spline curve; P i is the i-th control point; N i,p (u) is the i-th p-th B-spline basis function of the i-th control point; i is a first ordinal parameter; p is an order parameter; u is a control point on the B-spline curve; n is the total number of control points.

[0081] In an optional embodiment, the expression of the B-spline curve basis function is:

[0082] The expression of the zero-order basis function, i.e. p = 0:

[0083]

[0084] The expression of the high-order basis function, i.e. p > 0:

[0085]

[0086] where N i,0 (u) is the i-th 0-th B-spline basis function of the i-th control point; u i is the i-th control point on the B-spline curve; ui+1 is the i+1th control point on the B-spline curve; u i+p is the i+pth control point on the B-spline curve; u i+p+1 is the i+p+1th control point on the B-spline curve.

[0087] As can be seen from formula (1) to formula (3), the B-spline curve obtained by fitting is determined by the order parameter p, the weight vector and the node vector. The higher the order parameter p, the wider the influence range of the basis function, and the higher the smoothness and complexity of the curve obtained by fitting.

[0088] It should be noted that the order of the B-spline curve, the distribution area of the control point, the weight value, the node, the maximum distance and the maximum error of the B-spline curve in the embodiment can be set according to the actual situation, and the embodiment does not limit this.

[0089] Step 3.2: According to the B-spline curve of the generatrix of the ring wave-shaped part, the generatrix contour of the ring wave-shaped part is obtained by using a second-order difference identification algorithm.

[0090] As Figure 8 shown, in the embodiment, step 3.2 includes:

[0091] Step 3.2.1: According to the B-spline curve of the generatrix of the ring wave-shaped part, convolution calculation is performed based on a second-order difference operator, and feature extraction is performed to obtain edges and feature points on the B-spline curve;

[0092] Step 3.2.2: According to the edge curvature, the generatrix contour of the ring wave-shaped part is obtained; wherein the generatrix contour of the ring wave-shaped part includes a plurality of convex points and concave points, the convex points are the peak positions on the generatrix contour of the ring wave-shaped part, and the concave points are the valley positions on the generatrix contour of the ring wave-shaped part.

[0093] The principle is that according to the scanned generatrix contour, the ring wave-shaped part is inversely fitted based on the B-spline curve, that is, the B-spline curve of the generatrix of the ring wave-shaped part is fitted from the scanning result, and then the generatrix contour of the ring wave-shaped part is obtained based on the second-order difference identification algorithm, the peak and valley positions on the generatrix contour are determined, and finally the actual axial and normal machining positions of the hole arrangement on the ring wave-shaped part are determined by repositioning according to the peak and valley positions.

[0094] In an optional embodiment, the expression of the second-order difference identification algorithm is:

[0095] For a one-dimensional signal, the expression of the discrete form of the second-order difference is:

[0096] f''(j) = f(j+1) - 2f(j) + f(j-1) (4);

[0097] Wherein, f(j) is the gray value of the jth point on the B-spline curve; j is the first ordinal parameter; f''(j) is the second-order difference discrete function of f(j).

[0098] In a two-dimensional image, the second-order difference is usually implemented by a Laplacian, whose expression is:

[0099]

[0100] Wherein, is the second-order difference operator; x is the first parameter; y is the second parameter; is the partial derivative function.

[0101] It should be noted that the second-order difference recognition algorithm is an image processing method for detecting the edge and feature points of the gray level change trend in the image, which recognizes the significant change position by calculating the second-order derivative of the image gray level, and can be used for edge detection and feature extraction. The operator used in the second-order difference recognition algorithm of the embodiment is not limited, and the Laplacian is only an example, and the corresponding parameter setting can also be realized by referring to the existing related technology.

[0102] The principle is that the process of obtaining the generatrix profile of the ring wave type part can be divided into two steps. In the first step, based on convolution calculation such as Laplacian or similar operator, combined with zero-crossing point and extreme value detection, the edge and feature points are extracted; in the second step, the curvature extreme points are detected by analyzing the edge curvature, that is, the convex points and concave points are extracted and recognized, and the position and curvature information are stored. Combining the advantages of edge detection and curvature analysis, the accurate recognition of convex and concave points is realized.

[0103] The obtained generatrix profile of the ring wave type part is shown in Figure 10 The generatrix profile, convex points and concave points are shown, wherein the concave points correspond to the wave troughs of the ring wave type part, and the convex points correspond to the wave peaks of the ring wave type part. According to the generatrix profile, the machining has higher precision, and the errors of the generatrix direction machining position degree and the machining direction caused by the deformation of the part can be solved. At the same time, for the machining of the ring wave type part, the positioning accuracy and positioning time can be greatly improved.

[0104] The axial positioning method for the ring wave type part of the application realizes the generatrix position information of the complex workpiece such as the ring wave type part based on simple scanning, and then reversely fits the generatrix of the ring wave type part based on the scanning result, so that the wave peak and wave trough after deformation are obtained by fitting the profile after deformation of the ring wave type part, the influence of the wave distance deviation of the ring wave type part caused by local deformation on the positioning accuracy and machining accuracy is solved, and the positioning accuracy and part machining quality are ensured.

[0105] In other words, the annular wave-shaped part has positioning difficulty after local deformation, and the positioning accuracy and machining accuracy are ensured by scanning-reverse fitting and peak and valley positioning.

[0106] As shown in Figure 11 the same inventive concept, the second aspect of the present application proposes an axial positioning device for an annular wave-shaped part, which uses the axial positioning method for an annular wave-shaped part of the first aspect;

[0107] The axial positioning device for an annular wave-shaped part of the second aspect of the present application comprises a distance measuring module and a data acquisition and processing module; wherein the distance measuring module is used to position the generatrix highest point and the generatrix lowest point of the annular wave-shaped part respectively, and scan the annular wave-shaped part along the first direction to obtain the generatrix position information of the annular wave-shaped part; the data acquisition and processing module is used to perform reverse fitting according to the generatrix position information to obtain the generatrix contour of the annular wave-shaped part.

[0108] Based on the same inventive concept, the third aspect of the present application proposes an axial positioning system for an annular wave-shaped part, which comprises a machining machine tool and the axial positioning device for an annular wave-shaped part of the second aspect, and the distance measuring module is arranged on the movement module of the machining machine tool and moves with the movement module of the machining machine tool to obtain the generatrix position information of the annular wave-shaped part in real time through movement scanning.

[0109] For example, the distance measuring device can be a laser distance measuring device, such as a laser range finder.

[0110] It should be noted that the effective range of the distance measuring device should be greater than the maximum distance between the peak and the valley of the annular wave-shaped part, i.e. the height difference between the generatrix highest point and the generatrix lowest point of the annular wave-shaped part. Under the premise of meeting the effective range, the smaller the range, the higher the accuracy.

[0111] The principle is that the laser range finder is fixed on the movement module of the machining machine tool, and the laser range finder is installed parallel to the normal of the annular wave-shaped part, the emitting element emits several laser beams to the annular wave-shaped part, and the receiving element of the laser range finder receives the laser beams reflected back by the surface of the annular wave-shaped part, and the distance from the surface of the annular wave-shaped part is calculated by the time from the emission to the reception of the laser beams, so as to determine the position information of the corresponding position.

[0112] The circular wave-shaped part is fixed on a horizontal worktable of a machining tool, and the distance measuring module is arranged on a moving module of the machining tool and moves along the axial direction and the surface normal direction of the circular wave-shaped part, specifically, moves to the highest point of the generatrix of the circular wave-shaped part in the axial direction, moves close to the highest point of the generatrix in the normal direction, so that the distance between the distance measuring module and the surface of the circular wave-shaped part is within the effective range of the distance measuring module, the normal position is measured, and thus the position information of the highest point of the generatrix, i.e., the first measurement point, is obtained; similarly, the lowest point of the generatrix of the circular wave-shaped part is moved to in the axial direction, the lowest point of the generatrix is moved close to in the normal direction, and the normal position is measured, and thus the position information of the lowest point of the generatrix, i.e., the second measurement point, is obtained.

[0113] Further, the circular wave-shaped part is scanned in the first direction in real time under the driving of the moving module, and the position information of the generatrix of the circular wave-shaped part is obtained, and the positioning work of the complex workpiece such as the circular wave-shaped part can be satisfied by simple scanning. The first direction is parallel to the direction of the line segment between the highest point of the generatrix and the lowest point of the generatrix, for example, the highest point of the generatrix can be scanned to the lowest point of the generatrix, or the lowest point of the generatrix can be scanned to the highest point of the generatrix.

[0114] It should be noted that, in the present document, the relational terms such as first and second and the like can merely be used to differentiate one entity or action from another, without necessarily requiring or implying any actual relationship or order between or among the entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprises", or "comprising", does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. The terms "connected" or "coupled" or the like do not necessarily mean physically or mechanically connected or coupled, but can include an electrical connection, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like indicate the orientation or positional relationship based on the drawings shown, and are only used for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0115] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, a number of simple deductions or substitutions can be made without departing from the concept of the present application, and all of them should be regarded as falling within the protection scope of the present application.

Claims

1. A method for axial positioning of annular corrugated parts, characterized in that: include: The method comprises: fixing the annular corrugated part on a horizontal workbench; setting the highest point of the busbar as a first measuring point, and measuring the position of the first measuring point along a second direction and a third direction to locate the highest point of the busbar of the annular corrugated part; wherein the second direction is a surface normal direction of the annular corrugated part, and the third direction is an axial direction of the annular corrugated part; setting the lowest point of the busbar as a second measuring point, and measuring the position of the second measuring point along the second direction and the third direction to locate the lowest point of the busbar of the annular corrugated part; Scanning the annular corrugated part along a first direction to obtain busbar position information of the annular corrugated part; the first direction is parallel to the direction of the line connecting the highest point of the busbar and the lowest point of the busbar; Performing inverse fitting based on the busbar position information to obtain the busbar profile of the annular wave-shaped part, including: using a B-spline curve fitting method to obtain a B-spline curve of the busbar of the annular wave-shaped part based on the busbar position information; and using a second-order difference recognition algorithm based on the B-spline curve of the busbar of the annular wave-shaped part to obtain the busbar profile of the annular wave-shaped part; The busbar profile of the annular corrugated part includes a plurality of wave crests and a plurality of wave troughs on the busbar profile of the annular corrugated part.

2. The axial positioning method for annular corrugated parts according to claim 1, characterized in that: According to the busbar position information, a B-spline curve fitting method is used to obtain a B-spline curve of the annular wave-shaped part, including: The order, control point distribution area, weight value and node of the B-spline curve are respectively set, and a plurality of expected contour points are generated according to the busbar position information; The maximum distance and the maximum error of the B-spline curve are respectively set, and the B-spline curve of the annular corrugated part is obtained according to a plurality of expected contour points.

3. The axial positioning method for annular corrugated parts according to claim 2, characterized in that: The expression of the B-spline curve is: ； in, is the parametric equation of the B-spline curve; For the control points; For the The first control point indivual Basis functions of sub-B-spline curves; is the first ordinal parameter; is the order parameter; are the control points on the B-spline curve; is the total number of control points.

4. The axial positioning method for annular corrugated parts according to claim 3, characterized in that: The expression of the basis function of the B-spline curve is: ； ； in, For the The first control point Basis functions of the 0-degree B-spline curve; is the first control points.

5. The axial positioning method for annular corrugated parts according to claim 1, characterized in that: According to the B-spline curve of the generatrix of the annular wave-shaped part, a second-order difference recognition algorithm is used to obtain the generatrix profile of the annular wave-shaped part, including: According to the B-spline curve of the annular wave-shaped part busbar, a convolution calculation is performed based on a second-order difference operator, and feature extraction is performed to obtain edges and feature points on the B-spline curve; The edge curvature is analyzed according to the edge and the characteristic point to obtain the busbar profile of the annular wavy part; wherein, the busbar profile of the annular wavy part includes a plurality of convex points and concave points, the convex points are the peak positions on the busbar profile of the annular wavy part, and the concave points are the trough positions on the busbar profile of the annular wavy part.

6. The axial positioning method for annular corrugated parts according to claim 5, characterized in that: The expression of the second-order difference identification algorithm is: ； ； in, is the first Gray value of each point; is the first ordinal parameter; for The second-order difference dispersion function of is the second-order difference operator; is the first parameter; is the second parameter; is the partial derivative function.

7. An axial positioning device for annular corrugated parts, characterized in that: Using the axial positioning method for annular wave-shaped parts according to any one of claims 1 to 6, the axial positioning device includes: a distance measurement module and a data acquisition and processing module; The distance measuring module is used to respectively locate the highest point and the lowest point of the busbar of the annular corrugated part, and scan the annular corrugated part along the first direction to obtain the busbar position information of the annular corrugated part; The data acquisition and processing module is used to perform inverse fitting based on the busbar position information to obtain the busbar profile of the annular wave-shaped part.

8. An axial positioning system for annular corrugated parts, characterized in that: include: A processing machine tool and an axial positioning device for annular corrugated parts according to claim 7; The distance measuring module is arranged on the motion module of the processing machine tool and moves with the motion module of the processing machine tool to obtain the busbar position information of the annular wave-shaped part in real time through motion scanning.

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