Geometric feature extraction method and detection method of blade and related device

Abstract

The invention relates to the field of aviation, and provides a geometric feature extraction method and detection method of a blade and a related device, and the method comprises the steps: generating a plurality of section planes of the blade along a stacking axis; determining a blade profile of the blade according to each section plane; according to the blade profile, geometrical characteristics of the blade are extracted, and the geometrical characteristics comprise at least one of a chord line, a mean camber line, the maximum thickness, the front edge thickness and the rear edge thickness. Therefore, according to the method, the intercepted blade profile can be quickly determined based on the improved section method, then the geometric features of the blade are obtained through calculation, the efficiency is high, and the calculation result is accurate.

Description

Technical Field

[0001] The present invention relates to the field of aviation, and particularly to a method for extracting geometric features of blades, a detection method and related devices. Background Art

[0002] Blades are important components of aircraft and play an important role in the energy conversion efficiency and service life of engines. The geometric shape of the blades affects the energy conversion efficiency and service life of the engines. Therefore, how to quickly and accurately extract the geometric features of the blades has become a technical problem to be solved urgently by those skilled in the art. Summary of the Invention

[0003] In view of the above problems, the present invention provides a method for extracting geometric features of blades, a detection method and related devices that overcome or at least partially solve the above problems.

[0004] In a first aspect, a method for extracting geometric features of a blade includes:

[0005] Generating a plurality of sectional planes of the blade along the stacking axis;

[0006] Determining the blade profile line according to each of the sectional planes;

[0007] Extracting the geometric features of the blade according to the blade profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

[0008] Optionally, in some alternative embodiments, the extracting the geometric features of the blade according to the blade profile line includes:

[0009] Calculating the convex hull of the blade profile line, and calculating a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull;

[0010] Calculating the mean camber line and the maximum thickness according to the suction side point set and the pressure side point set;

[0011] Calculating the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set.

[0012] Optionally, in some alternative embodiments, the calculating the convex hull of the blade profile line, and calculating a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull includes:

[0013] Using a convex hull algorithm to calculate the blade profile line to obtain the corresponding convex hull;

[0014] Selecting two points with the largest adjacent distance in the convex hull as the approximate chord line endpoints;

[0015] For any one of the approximate chord endpoints, the approximate chord endpoint and the three adjacent blade profile points on the left and right of the approximate chord endpoint are fitted by the least squares method to obtain a first fitted circle. Among them, one approximate chord endpoint corresponds to one first fitted circle. The blade profile points are from the blade profile point cloud, and the blade profile point cloud is a set of blade profile points of the blade profile line;

[0016] Traverse each point in the blade profile point cloud to obtain the points whose distance from the first fitted circle is less than a preset threshold as the first point set;

[0017] Use the least squares method to fit the first point set to obtain a second fitted circle, and iterate the fitting until the obtained point set no longer changes;

[0018] Obtain the leading edge point set and the trailing edge point set from the point set that no longer changes, and obtain the suction side point set and the pressure side point set from the points outside the point set that no longer changes;

[0019] Use the least squares method to fit the leading edge point set and the trailing edge point set respectively to obtain the leading edge circle and the trailing edge circle;

[0020] Calculate the common tangent of the leading edge circle and the trailing edge circle as the chord line.

[0021] Optionally, in some alternative embodiments, the calculating the mean camber line and the maximum thickness according to the suction side point set and the pressure side point set includes:

[0022] Fit the pressure side point set and the suction side point set respectively to obtain the corresponding B-spline curves;

[0023] Calculate the intersection point of the normal line of the B-spline curve corresponding to the pressure side point set and the normal line of the B-spline curve corresponding to the suction side point set;

[0024] Calculate the first distance from the intersection point to each of the pressure side point sets;

[0025] Calculate the second distance from the intersection point to each of the suction side point sets;

[0026] Calculate the difference between the first distance and the second distance. If the difference between the distances is less than a preset distance threshold, determine the corresponding intersection point as a point on the mean camber line, and fit the mean camber line in this way;

[0027] Select the diameter of the inscribed circle with the largest radius as the maximum thickness, where the inscribed circle is a circle with a point on the mean camber line as the center and is inscribed in both the B-spline curve corresponding to the pressure side point set and the B-spline curve corresponding to the suction side point set.

[0028] Optionally, in some alternative embodiments, calculating the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set includes:

[0029] Fitting a leading edge circle according to the leading edge point set;

[0030] Fitting a trailing edge circle according to the trailing edge point set;

[0031] Taking the center of the leading edge circle as the center and 1.5 times the radius of the leading edge circle as the radius to draw a circle, obtaining a first concentric circle;

[0032] Taking the center of the trailing edge circle as the center and 1.5 times the radius of the trailing edge circle as the radius to draw a circle, obtaining a second concentric circle;

[0033] Determining a first intersection point of the first concentric circle and the mean camber line;

[0034] Determining a second intersection point of the second concentric circle and the mean camber line;

[0035] Determining a third intersection point of the first normal line and the suction side line and a fourth intersection point of the first normal line and the pressure side line, wherein the first normal line is the normal line passing through the first intersection point, the suction side line is the curve formed by the suction side point set, and the pressure side line is the curve formed by the pressure side point set;

[0036] Determining a fifth intersection point of the second normal line and the suction side line and a sixth intersection point of the first normal line and the pressure side line, wherein the second normal line is the normal line passing through the second intersection point;

[0037] Calculating the distance between the third intersection point and the fourth intersection point to obtain the leading edge thickness;

[0038] Calculating the distance between the fifth intersection point and the sixth intersection point to obtain the trailing edge thickness.

[0039] Optionally, in some alternative embodiments, after calculating the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set, the method further includes:

[0040] Comparing the chord line, the mean camber line, the maximum thickness, the leading edge thickness and the trailing edge thickness with the CAD model and generating a corresponding data monitoring report.

[0041] Optionally, in some alternative embodiments, generating a plurality of sectional planes of the blade along the stacking axis includes:

[0042] Generating a plurality of sectional planes of the blade at equal intervals along the stacking axis of the blade according to a preset distance, wherein one sectional plane is generated at one interval.

[0043] Optionally, in some alternative embodiments, determining the blade profile line of the blade according to each of the cross-sectional planes includes:

[0044] For any cross-sectional plane, calculate the intersection line of the cross-sectional plane and a preset blade grid to obtain the corresponding profile line.

[0045] Optionally, in some alternative embodiments, for any cross-sectional plane, calculating the intersection line of the cross-sectional plane and a preset blade grid to obtain the corresponding profile line includes:

[0046] For any cross-sectional plane, intercept the intersection line of the cross-sectional plane and the preset blade grid from the preset blade grid to obtain the corresponding profile line, where one cross-sectional plane corresponds to one profile line, and the preset blade grid is a three-dimensional solid model pre-generated based on the blade.

[0047] In a second aspect, a method for verifying geometric features of a blade includes:

[0048] Compare the geometric features extracted above with a pre-established CAD model and generate a corresponding data monitoring report.

[0049] In a third aspect, a device for extracting geometric features of a blade includes: a plane generation unit, a profile line obtaining unit, and a feature extraction unit;

[0050] The plane generation unit is configured to generate a plurality of cross-sectional planes of the blade along the stacking axis;

[0051] The profile line obtaining unit is configured to determine the profile line of the blade according to each of the cross-sectional planes;

[0052] The feature extraction unit is configured to extract the geometric features of the blade according to the profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

[0053] In a fourth aspect, a computer-readable storage medium stores a program thereon, and when the program is executed by a processor, it implements the method for extracting geometric features of a blade according to any one of the above.

[0054] In a fifth aspect, an electronic device includes at least one processor, at least one memory connected to the processor, and a bus; wherein, the processor and the memory communicate with each other through the bus; the processor is configured to call program instructions in the memory to execute the method for extracting geometric features of a blade according to any one of the above.

[0055] With the above technical solution, a method for extracting geometric features of a blade, a detection method, and related devices provided by the present invention can generate a plurality of cross-sectional planes of the blade along the stacking axis; determine the blade profile line according to each of the cross-sectional planes; and extract the geometric features of the blade according to the blade profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness. It can be seen from this that the present invention can quickly determine the intercepted blade profile line based on the improved cross-section method, and then calculate the geometric features of the blade, with high efficiency and accurate calculation results.

[0056] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features, and advantages of the present invention more obvious and understandable, the following specifically illustrates the specific embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0058] Figure 1 shows a flowchart of a method for extracting geometric features of a blade provided by the present invention;

[0059] Figure 2 shows a schematic diagram of equally spaced intercepted cross-sectional planes of a blade provided by the present invention;

[0060] Figure 3 shows a schematic diagram of the intersection of a three-dimensional solid model and a cross-sectional plane provided by the present invention;

[0061] Figure 4 shows a schematic diagram of an approximate chord line provided by the present invention;

[0062] Figure 5 shows a schematic diagram of selecting left and right adjacent blade profile points provided by the present invention;

[0063] Figure 6 shows a schematic diagram of a common tangent line of a leading edge circle and a trailing edge circle provided by the present invention;

[0064] Figure 7 shows a schematic diagram of a B-spline curve obtained by fitting provided by the present invention;

[0065] Figure 8 shows a schematic diagram of determining the intersection point of the normal lines provided by the present invention;

[0066] Figure 9 Shows a schematic diagram of calculating the distance from an intersection point to a curve provided by the present invention;

[0067] Figure 10 Shows a schematic diagram of determining the mean camber line of a blade provided by the present invention;

[0068] Figure 11 Shows a schematic diagram of determining the maximum thickness of a blade provided by the present invention;

[0069] Figure 12 Shows a schematic diagram of determining the leading edge thickness and trailing edge thickness of a blade provided by the present invention;

[0070] Figure 13 Shows a schematic structural diagram of a device for extracting geometric features of a blade provided by the present invention;

[0071] Figure 14 Shows a schematic structural diagram of an electronic device provided by the present invention. Detailed implementation manners

[0072] Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0073] As Figure 1 shown, the present invention provides a method for extracting geometric features of a blade, including: S100, S200, and S300;

[0074] S100. Generate a plurality of cross-sectional planes of the blade along the stacking axis;

[0075] Optionally, the stacking axis mentioned in the present invention is an axis system designed through precision, which combines and fixes a plurality of blades at a certain angle and in a certain order to form a set of mechanical components with specific functions. Different from traditional single blades, this stacking method can achieve diverse performance outputs on the same axis. For specific details, please refer to the detailed description of the stacking axis in the art. It should be noted that the blades mentioned in the present invention can be aviation blades, and the present invention will not describe this in detail.

[0076] Optionally, the present invention can set a certain distance according to actual needs and intercept and generate a plurality of cross-sectional planes of the blade at equal intervals according to this distance, and the present invention does not limit this.

[0077] For example, in some optional embodiments, the S100 includes: step 1.1;

[0078] Step 1.1, along the stacking axis of the blade, generate multiple cross-sectional planes of the blade at equal intervals according to a preset distance, wherein one cross-sectional plane is generated at one interval.

[0079] Optional, see Figure 2 The schematic diagram of the section plane generated by isometric cutting of the blade is shown, where Figure 2 The crescent-shaped plane surrounded by the middle blue curve in the figure is the cross-sectional plane. Figure 2 It is not difficult to see that the present invention can generate multiple blue crescent-shaped cross-sectional planes along the stacking axis, and the distance between two adjacent blue crescent-shaped cross-sectional planes is the preset distance, and the present invention does not impose any limitation on this.

[0080] It should be noted that: Figure 2 The crescent-shaped plane in the figure is a cross section, and the width of the plane represents the thickness of the blade, which is not limited in the present invention.

[0081] S200, for any cross-sectional plane, calculating the intersection line between the cross-sectional plane and a preset blade grid to obtain a corresponding blade profile line;

[0082] For example, in some optional embodiments, the S200 includes: step 2.1;

[0083] Step 2.1, for any cross-sectional plane, cut the intersection line between the cross-sectional plane and the preset blade grid from the preset blade grid to obtain the corresponding blade profile line, wherein one cross-sectional plane corresponds to one blade profile line, and the preset blade grid is a three-dimensional model pre-generated based on the blade.

[0084] Optional, such as Figure 3 As shown, the present invention can generate a three-dimensional model based on the blade in advance, and the intersection line of the three-dimensional model and the cross-sectional plane, that is, Figure 3 The blue crescent-shaped intersection line in the figure is the blade profile line. It should be noted that the blade profile line represents the shape of the outer surface of the blade in the cross section, and the present invention does not limit this.

[0085] Optionally, in addition to extracting the blade profile by intersecting the blade grid with the cross-sectional plane, the present invention can also be based on other methods. For example, the present invention can directly calculate the cross-sectional plane through algorithm calculation, extract the edge curve of the cross-sectional plane, and obtain the blade profile, and the present invention is not limited to this.

[0086] S300, calculating the convex hull of the blade profile, and calculating a blade basin point set, a blade back point set, a leading edge point set, a trailing edge point set and a chord line according to the convex hull;

[0087] Optionally, in some alternative embodiments, S300 includes: Step 3.1, Step 3.2, and Step 3.3;

[0088] Step 3.1: Calculate the convex hull of the blade profile line, and based on the convex hull, calculate the leading edge point set, trailing edge point set, leading edge point set, trailing edge point set, and chord line;

[0089] Optionally, in some alternative embodiments, Step 3.1 includes: Step 4.1, Step 4.2, Step 4.3, Step 4.4, Step 4.5, Step 4.6, Step 4.7, and Step 4.8;

[0090] Step 4.1: Use the convex hull algorithm to calculate the blade profile line to obtain the corresponding convex hull;

[0091] Optionally, the convex hull algorithm is a well-known technical concept in the art, and the present invention will not describe it in detail. For specific details, please refer to the relevant descriptions in the art. It should be noted that: The convex hull is a core concept in computational geometry used to describe the smallest convex structure that contains a given set of points. The convex hull appears as the smallest convex polygon in two-dimensional space and as the smallest convex polyhedron in three-dimensional space. Its core value lies in capturing the distribution characteristics of the point set through a simple geometric boundary and providing key support in multiple fields (such as computer graphics and data analysis).

[0092] Step 4.2: Select the two points with the largest adjacent distance in the convex hull as the approximate chord line endpoints;

[0093] Optionally, the present invention can traverse the pairwise adjacent vertices of the polygon in order, calculate the distance between the pairwise adjacent vertices, and then select the two vertices with the largest distance as the approximate chord line endpoints. The present invention does not limit this.

[0094] Optionally, for the approximate chord line endpoints, for the endpoints at both ends of the approximate chord line corresponding to the approximate chord line endpoints, please specifically refer to Figure 4 , where Figure 4 the blue line in can be understood as the approximate chord line, and the endpoints at both ends of the approximate chord line are the approximate chord line endpoints, and they are also the two points with the largest adjacent distance in the convex hull. The present invention does not limit this.

[0095] Step 4.3: For any one of the approximate chord line endpoints, fit the approximate chord line endpoint and the three blade profile points adjacent to the left and right of the approximate chord line endpoint using the least squares method to obtain a first fitting circle. Among them, one approximate chord line endpoint corresponds to one first fitting circle. The blade profile points are from the blade profile line point cloud, and the blade profile line point cloud is a set of blade profile points of the blade profile line;

[0096] Optionally, in combination with the foregoing Figure 3For the description, the blade profile line is in a shape similar to a crescent moon. Each curve is composed of many points. Therefore, the blade profile line can correspond to a blade profile point cloud composed of many blade profile points, and the present invention does not limit this.

[0097] Optionally, the blade profile points on the blade profile line are ordered. Therefore, the present invention can select three blade profile points adjacent to the left and right of the approximate chord endpoint in sequence. For example, for the approximate chord endpoint 1, the present invention can select 3 blade profile points to the left of the approximate chord endpoint 1 and 3 blade profile points to the right of the approximate chord endpoint 1, including the approximate chord endpoint 1 itself, a total of 7 points. For the approximate chord endpoint 2, the present invention can select 3 blade profile points to the left of the approximate chord endpoint 2 and 3 blade profile points to the right of the approximate chord endpoint 2, including the approximate chord endpoint 2 itself, a total of 7 points. For example Figure 5 As shown, the red dots are the approximate chord endpoint 1 or the approximate chord endpoint 2, and the 3 blue triangle points on both sides of the red dots are the three adjacent blade profile points on the left and right. The blue line is the aforementioned approximate chord, and the present invention does not limit this.

[0098] Optionally, based on Figure 5 It can be known that whether it is the approximate chord endpoint 1 or the approximate chord endpoint 2, the present invention fits according to the 3 blade profile points on its left and right to obtain a corresponding first fitted circle. That is, the approximate chord endpoint 1 corresponds to a first fitted circle obtained by fitting, and the approximate chord endpoint 2 corresponds to another first fitted circle obtained by fitting, and the present invention does not limit this.

[0099] Step 4.4: Traverse each point in the blade profile point cloud to obtain the points whose distance from the first fitted circle is less than a preset threshold as the first point set;

[0100] Optionally, as described above, whether it is the approximate chord endpoint 1 or the approximate chord endpoint 2, the present invention fits to obtain the corresponding first fitted circle, that is, the present invention fits two first fitted circles. For any one of the first fitted circles, the present invention traverses each blade profile point in the blade profile point cloud and calculates the points whose distance from the first fitted circle is less than the preset threshold, that is, one first fitted circle corresponds to one first point set. It should be noted that: the distance between the blade profile point and the first fitted circle is also the distance between the point on the blade profile point cloud and the circumference of the first fitted circle (that is, the distance from the blade profile point to the center of the first fitted circle minus the radius of the first fitted circle), and the present invention does not limit this.

[0101] Step 4.5: Use the least squares method to fit the first point set to obtain a second fitted circle, and iterate the fitting until the obtained point set no longer changes;

[0102] Optionally, as described above, a first set of points is obtained corresponding to a first fitting circle. For each first set of points, the present invention uses the least squares method to fit the first set of points to obtain a second fitting circle.

[0103] It should be noted that: in this process of the present invention, the fitting process is repeatedly executed. That is, after the second fitting circle is obtained for the first time, the present invention traverses each point in the blade profile point cloud, and obtains the points whose distance from the second fitting circle is less than a preset threshold as the first set of points, and then refits based on the newly obtained first set of points to obtain a new second fitting circle until the obtained first set of points no longer changes. The present invention does not limit this.

[0104] Step 4.6: Obtain the leading edge point set and the trailing edge point set from the unchanging point set, and obtain the blade suction side point set and the blade pressure side point set from the points other than the unchanging point set;

[0105] Optionally, as described above, the present invention performs the above iterative fitting operations at the two end points of the approximate chord line respectively, so two unchanging point sets can be obtained. The present invention can use these two point sets as the corresponding leading edge point set and trailing edge point set.

[0106] Optionally, on the basis of obtaining the above leading edge point set and trailing edge point set, the blade profile point cloud is segmented based on the above leading edge point set and trailing edge point set. The other blade profile points except the leading edge point set and the trailing edge point set will be used as the blade suction side point set and the blade pressure side point set respectively, without remainder. The present invention does not limit this.

[0107] Step 4.7: Use the least squares method to fit the leading edge point set and the trailing edge point set respectively to obtain a leading edge circle and a trailing edge circle;

[0108] Step 4.8: Calculate the common tangent of the leading edge circle and the trailing edge circle as the chord line.

[0109] Optionally, as Figure 6 shown, Figure 6 the two red circles in Figure 6 can be understood as the leading edge circle and the trailing edge circle obtained by fitting in Step 4.7. Generally speaking, the thickness of the leading edge is greater than that of the trailing edge, that is, Figure 6 the larger red circle in

[0110] is the leading edge circle, and Figure 6The blue straight line in [[]] can immediately be the chord line calculated in step 4.8. It should be noted that: the chord line obtained in step 4.8 here is relatively accurate and is calculated after obtaining the leading edge circle and the trailing edge circle. The aforementioned approximate chord line is obtained through rough calculation and may have a certain gap from the actual real chord line. The present invention does not limit this.

[0111] Step 3.2: Calculate the mean camber line and the maximum thickness according to the set of suction side points and the set of pressure side points.

[0112] Optionally, in some alternative embodiments, step 3.2 includes: step 5.1, step 5.2, step 5.3, step 5.4, step 5.5 and step 5.6.

[0113] Step 5.1: Respectively fit the set of pressure side points and the set of suction side points to obtain corresponding B-spline curves.

[0114] Optionally, as Figure 7 shown, Figure 7 the green curve and the blue curve in [[]] can be respectively understood as the B-spline curve corresponding to the set of suction side points obtained by fitting and the B-spline curve corresponding to the set of pressure side points, where Figure 7 the green curve in [[]] is the B-spline curve corresponding to the set of suction side points, Figure 7 the blue curve in [[]] is the B-spline curve corresponding to the set of pressure side points. The present invention does not limit this.

[0115] It should be noted that: the B-spline curve is a technical concept well-known in the art. The present invention does not describe it in detail. For specific details, please refer to the relevant descriptions in the art.

[0116] Step 5.2: Calculate the intersection point of the normal line of the B-spline curve corresponding to the set of suction side points and the normal line of the B-spline curve corresponding to the set of pressure side points.

[0117] Optionally, taking the set of suction side points as an example, for each point in the set of suction side points, the present invention needs to calculate the intersection point of the normal line passing through this point (i.e., the normal line of the B-spline curve corresponding to the set of suction side points) and the normal line of each point in the set of pressure side points (i.e., the normal line of the B-spline curve corresponding to the set of pressure side points). The specific calculation process is the intersection of straight lines. For example, as Figure 8 shown, where, a normal line passing through a point (the red dot on the blue curve) of the B-spline curve corresponding to the set of suction side points intersects with the normal lines of the points (the two red dots on the green curve) of the B-spline curve corresponding to the set of pressure side points respectively, obtaining two intersection points, one intersection point is inside the blade profile line, and one intersection point is outside the blade profile line.

[0118] Optionally, as described above, for a point on the back of the blade, it can correspond to multiple intersection points, because the normal lines passing through different points on the front of the blade and the normal line passing through this point on the back of the blade have intersection points (except when the two normal lines are parallel), and the present invention does not limit this.

[0119] Step 5.3: Calculate the first distance from the intersection point to each set of points on the back of the blade.

[0120] Step 5.4: Calculate the second distance from the intersection point to each set of points on the front of the blade.

[0121] Optionally, for each intersection point, the present invention can calculate the first distance from the intersection point to the set of points on the back of the blade and the second distance from the intersection point to the set of points on the front of the blade. For example, as Figure 9 shown, for any intersection point, the present invention calculates d1 and d2, corresponding to the distance from the intersection point to the B-spline curve of the set of points on the front of the blade and the distance from the intersection point to the B-spline curve of the set of points on the back of the blade, and the present invention does not limit this.

[0122] Step 5.5: Calculate the difference between the first distance and the second distance. If the difference between the distances is less than a preset distance threshold, determine the corresponding intersection point as a point on the middle arc, and thus fit the middle arc.

[0123] Optionally, the present invention can set the preset distance threshold to a threshold close to 0 or equal to 0. That is, when the difference between the first distance and the second distance is close to 0 or equal to 0, determine that the intersection point is a point on the middle arc, and the present invention does not limit this.

[0124] Optionally, the middle arc can be understood as the arc formed by the centers of the inscribed circles of the blade profile. Specifically, as Figure 10 shown, the middle red arc is the middle arc, and the present invention does not limit this.

[0125] Step 5.6: Select the diameter of the inscribed circle with the largest radius as the maximum thickness, where the inscribed circle is a circle with a point on the middle arc as the center and is inscribed with both the B-spline curve corresponding to the set of points on the back of the blade and the B-spline curve corresponding to the set of points on the front of the blade.

[0126] Optionally, as Figure 10 shown, with a point on the middle arc as the center, multiple inscribed circles of the blade profile can be made. Therefore, the present invention can select the diameter of the largest inscribed circle as the maximum thickness of the blade. For example, as Figure 11 shown, the circle is the largest inscribed circle, so the diameter of this inscribed circle is the maximum thickness, and the present invention does not limit this.

[0127] Step 3.3: Calculate the leading-edge thickness and the trailing-edge thickness according to the set of leading-edge points and the set of trailing-edge points.

[0128] Optionally, in some alternative embodiments, step 3.3 includes: step 6.01, step 6.02, step 6.03, step 6.04, step 6.05, step 6.06, step 6.07, step 6.08, step 6.09, and step 6.10;

[0129] Step 6.01: Fit a leading-edge circle based on the set of leading-edge points;

[0130] Step 6.02: Fit a trailing-edge circle based on the set of trailing-edge points;

[0131] Optionally, referring to Figure 6 the embodiments shown Figure 6 the two red circles in can be respectively understood as the leading-edge circle and the trailing-edge circle, and the present invention will not elaborate on this.

[0132] Step 6.03: Use the center of the leading-edge circle as the center and 1.5 times the radius of the leading-edge circle as the radius to draw a circle, obtaining a first concentric circle;

[0133] Step 6.04: Use the center of the trailing-edge circle as the center and 1.5 times the radius of the trailing-edge circle as the radius to draw a circle, obtaining a second concentric circle;

[0134] Optionally, as shown in Figure 12 the two blue circles in are respectively the first concentric circle and the second concentric circle, and their radii are respectively equal to 1.5 times the red circles inside them, and the present invention does not limit this. Figure 12

[0135] Step 6.05: Determine the first intersection point of the first concentric circle and the middle arc;

[0136] Step 6.06: Determine the second intersection point of the second concentric circle and the middle arc;

[0137] Optionally, as shown in Figure 12 the two blue circles in both have intersection points with the middle red curve (the middle arc), and the present invention can calculate to determine the coordinates of the first intersection point and the second intersection point. Of course, the present invention can also determine the first intersection point and the second intersection point by drawing, and the present invention does not limit this.

[0138] Step 6.07: Determine the third intersection point of the first normal line and the blade suction surface line and the fourth intersection point of the first normal line and the blade pressure surface line, where the first normal line is the normal line passing through the first intersection point, the blade suction surface line is the curve formed by the set of blade suction surface points, and the blade pressure surface line is the curve formed by the set of blade pressure surface points;

[0139] ​Step 6.08: Determine the fifth intersection point of the second normal line and the blade suction surface line, and the sixth intersection point of the first normal line and the blade pressure surface line, where the second normal line is the normal line passing through the second intersection point;

[0140] Step 6.09: Calculate the distance between the third intersection point and the fourth intersection point to obtain the leading edge thickness;

[0141] Step 6.10: Calculate the distance between the fifth intersection point and the sixth intersection point to obtain the trailing edge thickness.

[0142] Optionally, in combination with the foregoing Figure 12 , Figure 12 The outer tangent line of the two blue circles shown (i.e., the blue line segment that is tangent to the blue circles and inside the blade profile line) corresponds to the leading edge thickness and the trailing edge thickness respectively. The present invention does not limit this. That is, the leading edge thickness and the trailing edge thickness are respectively equal to the diameters of the inscribed circles at both ends of the blade profile line.

[0143] Optionally, in some alternative embodiments, after calculating the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set, the method further includes: Step 7.1;

[0144] Step 7.1: Compare the chord line, the mean camber line, the maximum thickness, the leading edge thickness, and the trailing edge thickness with the CAD model, and generate a corresponding data monitoring report.

[0145] The present invention provides a method for verifying geometric features of a blade, including:

[0146] Compare the geometric features extracted above with a pre-established CAD model, and generate a corresponding data monitoring report.

[0147] That is, the present invention can compare geometric features such as the foregoing chord line, the mean camber line, the maximum thickness, the leading edge thickness, and the trailing edge thickness with the CAD model to verify the accuracy of the generated geometric features. The present invention does not limit this.

[0148] As Figure 13 shown, the present invention provides a device for extracting geometric features of a blade, including: a plane generation unit 100, a blade profile line acquisition unit 200, and a feature extraction unit 300;

[0149] The plane generation unit 100 is configured to generate a plurality of cross-sectional planes of the blade along the stacking axis;

[0150] The blade profile line acquisition unit 200 is configured to determine the blade profile line of the blade according to each of the cross-sectional planes;

[0151] The feature extraction unit 300 is configured to extract geometric features of the blade according to the blade profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

[0152] Optionally, in some alternative embodiments, the feature extraction unit 300 includes: a convex hull calculation subunit, a mean camber calculation subunit, and a leading and trailing edge calculation subunit;

[0153] The convex hull calculation subunit is configured to calculate the convex hull of the blade profile line, and calculate a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull;

[0154] The mean camber calculation subunit is configured to calculate the mean camber line and the maximum thickness according to the suction side point set and the pressure side point set;

[0155] The leading and trailing edge calculation subunit is configured to calculate the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set.

[0156] Optionally, in some alternative embodiments, the convex hull calculation subunit includes: a convex hull algorithm subunit, an endpoint selection subunit, a first fitting subunit, a first set subunit, a second fitting subunit, a set determination subunit, a leading and trailing circle fitting subunit, and a chord line obtaining subunit;

[0157] The convex hull algorithm subunit is configured to use a convex hull algorithm to calculate the blade profile line to obtain a corresponding convex hull;

[0158] The endpoint selection subunit is configured to select two points with the largest adjacent distance in the convex hull as approximate chord line endpoints;

[0159] The first fitting subunit is configured to, for any one of the approximate chord line endpoints, fit the approximate chord line endpoint and the three blade profile points adjacent to the left and right of the approximate chord line endpoint by the least squares method to obtain a first fitting circle, where one approximate chord line endpoint corresponds to one first fitting circle, and the blade profile points are from the blade profile line point cloud, and the blade profile line point cloud is a set of blade profile points of the blade profile line;

[0160] The first set subunit is configured to traverse each point in the blade profile line point cloud to obtain points with a distance less than a preset threshold from the first fitting circle as a first point set;

[0161] The second fitting subunit is configured to fit the first point set by the least squares method to obtain a second fitting circle, and perform iterative fitting until the obtained point set no longer changes;

[0162] The set determination subunit is configured to obtain a leading edge point set and a trailing edge point set from the set of points that no longer change, and obtain a blade suction side point set and a blade pressure side point set from the points outside the set of points that no longer change;

[0163] The front and rear circle fitting subunit is configured to respectively fit the leading edge point set and the trailing edge point set by using the least squares method to obtain a leading edge circle and a trailing edge circle;

[0164] The chord line obtaining subunit is configured to calculate a common tangent line of the leading edge circle and the trailing edge circle as the chord line.

[0165] Optionally, in some alternative embodiments, the mid-arc calculation subunit includes: a curve fitting subunit, a curve intersection calculation subunit, a first distance calculation subunit, a second distance calculation subunit, a mid-arc curve fitting subunit, and a maximum thickness determination subunit;

[0166] The curve fitting subunit is configured to respectively fit the blade pressure side point set and the blade suction side point set to obtain corresponding B-spline curves;

[0167] The curve intersection calculation subunit is configured to calculate an intersection point of the normal line of the B-spline curve corresponding to the blade pressure side point set and the normal line of the B-spline curve corresponding to the blade suction side point set;

[0168] The first distance calculation subunit is configured to calculate a first distance from the intersection point to each of the blade pressure side point sets;

[0169] The second distance calculation subunit is configured to calculate a second distance from the intersection point to each of the blade suction side point sets;

[0170] The mid-arc curve fitting subunit is configured to calculate a difference between the first distance and the second distance. If the difference between the distances is less than a preset distance threshold, it is determined that the corresponding intersection point is a point on the mid-arc, and the mid-arc is fitted accordingly;

[0171] The maximum thickness determination subunit is configured to select the diameter of the inscribed circle with the largest radius as the maximum thickness, where the inscribed circle is a circle with a point on the mid-arc as the center and is inscribed with both the B-spline curve corresponding to the blade pressure side point set and the B-spline curve corresponding to the blade suction side point set.

[0172] Optionally, in some alternative embodiments, the front and rear edge calculation subunit includes: a leading edge circle fitting subunit, a trailing edge circle fitting subunit, a first concentric circle subunit, a second concentric circle subunit, a first intersection point subunit, a second intersection point subunit, a third and fourth intersection point subunit, a fifth and sixth intersection point subunit, a leading edge thickness subunit, and a trailing edge thickness subunit;

[0173] The leading edge circle fitting subunit is used to fit a leading edge circle according to the set of leading edge points;

[0174] The trailing edge circle fitting subunit is used to fit a trailing edge circle according to the set of trailing edge points;

[0175] The first concentric circle subunit is used to draw a circle with the center of the leading edge circle as the center and 1.5 times the radius of the leading edge circle as the radius to obtain a first concentric circle;

[0176] The second concentric circle subunit is used to draw a circle with the center of the trailing edge circle as the center and 1.5 times the radius of the trailing edge circle as the radius to obtain a second concentric circle;

[0177] The first intersection point subunit is used to determine the first intersection point of the first concentric circle and the mid-arc line;

[0178] The second intersection point subunit is used to determine the second intersection point of the second concentric circle and the mid-arc line;

[0179] The third and fourth intersection point subunit is used to determine the third intersection point of the first normal line and the blade pressure side line and the fourth intersection point of the first normal line and the blade suction side line, where the first normal line is the normal line passing through the first intersection point, the blade pressure side line is the curve formed by the set of blade pressure side points, and the blade suction side line is the curve formed by the set of blade suction side points;

[0180] The fifth and sixth intersection point subunit is used to determine the fifth intersection point of the second normal line and the blade pressure side line and the sixth intersection point of the first normal line and the blade suction side line, where the second normal line is the normal line passing through the second intersection point;

[0181] The leading edge thickness subunit is used to calculate the distance between the third intersection point and the fourth intersection point to obtain the leading edge thickness;

[0182] The trailing edge thickness subunit is used to calculate the distance between the fifth intersection point and the sixth intersection point to obtain the trailing edge thickness.

[0183] Optionally, in some alternative embodiments, the apparatus further includes: a model comparison unit;

[0184] The model comparison unit is used to compare the chord line, the mid-arc line, the maximum thickness, the leading edge thickness, and the trailing edge thickness with the CAD model after calculating the leading edge thickness and the trailing edge thickness according to the set of leading edge points and the set of trailing edge points, and generate a corresponding data monitoring report.

[0185] Optionally, in some alternative embodiments, the plane generation unit 100 includes: a plane generation subunit;

[0186] The plane generation subunit is configured to generate a plurality of sectional planes of the blade at equal intervals along the stacking axis of the blade, where one sectional plane is generated at one interval.

[0187] Optionally, in some alternative embodiments, the airfoil acquisition unit 200 includes: an airfoil acquisition subunit;

[0188] The airfoil acquisition subunit is configured to calculate the intersection line of any sectional plane and a preset blade grid for any sectional plane, and obtain the corresponding airfoil.

[0189] Optionally, in some alternative embodiments, the airfoil acquisition subunit includes: an airfoil determination subunit;

[0190] The airfoil determination subunit is configured to intercept the intersection line of any sectional plane and the preset blade grid from the preset blade grid for any sectional plane, and obtain the corresponding airfoil, where one sectional plane corresponds to one airfoil, and the preset blade grid is a three-dimensional solid model pre-generated based on the blade.

[0191] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated herein.

[0192] The geometric feature extraction device of the blade includes a processor and a memory. The above plane generation unit 100, airfoil acquisition unit 200, feature extraction unit 300, etc. are all stored in the memory as program units, and the processor executes the above program units stored in the memory to implement corresponding functions.

[0193] The processor includes a kernel, and the kernel retrieves the corresponding program unit from the memory. One or more kernels can be set, and by adjusting the kernel parameters, the intercepted airfoil can be quickly determined based on the improved sectional method, and then the geometric features of the blade can be obtained through calculation, with high efficiency and accurate calculation results.

[0194] An embodiment of the present invention provides a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, the geometric feature extraction method of the blade is implemented.

[0195] An embodiment of the present invention provides a processor, and the processor is used to run a program, where when the program runs, the geometric feature extraction method of the blade is executed.

[0196] As Figure 14As shown in the figure, an embodiment of the present invention provides an electronic device 700, which includes at least one processor 701, at least one memory 702 connected to the processor 701, and a bus 703. Among them, the processor 701 and the memory 702 communicate with each other through the bus 703. The processor 701 is used to call program instructions in the memory 702 to execute the above-mentioned method for extracting geometric features of the blade. The electronic device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0197] The present invention also provides a computer program product, which is suitable for executing a program initialized with the following method steps when executed on an electronic device:

[0198] A method for extracting geometric features of a blade, including:

[0199] Generate a plurality of cross-sectional planes of the blade along the stacking axis;

[0200] Determine the blade profile line according to each of the cross-sectional planes;

[0201] Extract geometric features of the blade according to the profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

[0202] Optionally, in some alternative embodiments, the extracting geometric features of the blade according to the profile line includes:

[0203] Calculate the convex hull of the profile line, and calculate a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull;

[0204] Calculate the mean camber line and the maximum thickness according to the suction side point set and the pressure side point set;

[0205] Calculate the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set.

[0206] Optionally, in some alternative embodiments, the calculating the convex hull of the profile line and calculating a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull includes:

[0207] Use a convex hull algorithm to calculate the profile line to obtain the corresponding convex hull;

[0208] Select two points with the largest adjacent distance in the convex hull as the approximate chord line endpoints;

[0209] For any one of the approximate chord endpoints, the approximate chord endpoint and three adjacent blade profile points on the left and right of the approximate chord endpoint are fitted by the least squares method to obtain a first fitted circle. Among them, one approximate chord endpoint corresponds to one first fitted circle. The blade profile points are from the blade profile point cloud, and the blade profile point cloud is a set of blade profile points of the blade profile line;

[0210] Traverse each point in the blade profile point cloud to obtain the points whose distance from the first fitted circle is less than a preset threshold as the first point set;

[0211] Use the least squares method to fit the first point set to obtain a second fitted circle, and iterate the fitting until the obtained point set no longer changes;

[0212] Obtain the leading edge point set and the trailing edge point set from the point set that no longer changes, and obtain the suction side point set and the pressure side point set from the points outside the point set that no longer changes;

[0213] Use the least squares method to fit the leading edge point set and the trailing edge point set respectively to obtain a leading edge circle and a trailing edge circle;

[0214] Calculate the common tangent of the leading edge circle and the trailing edge circle as the chord line.

[0215] Optionally, in some alternative embodiments, the calculating the mean camber line and the maximum thickness according to the suction side point set and the pressure side point set includes:

[0216] Fit the suction side point set and the pressure side point set respectively to obtain corresponding B-spline curves;

[0217] Calculate the intersection point of the normal line of the B-spline curve corresponding to the suction side point set and the normal line of the B-spline curve corresponding to the pressure side point set;

[0218] Calculate the first distance from the intersection point to each point in the suction side point set;

[0219] Calculate the second distance from the intersection point to each point in the pressure side point set;

[0220] Calculate the difference between the first distance and the second distance. If the difference between the distances is less than a preset distance threshold, determine the corresponding intersection point as a point on the mean camber line, and thus fit the mean camber line;

[0221] Select the diameter of the inscribed circle with the largest radius as the maximum thickness, where the inscribed circle is a circle with a point on the mean camber line as the center and is inscribed in both the B-spline curve corresponding to the suction side point set and the B-spline curve corresponding to the pressure side point set.

[0222] Optionally, in some alternative embodiments, calculating the leading edge thickness and the trailing edge thickness according to the leading edge point set and the trailing edge point set includes:

[0223] Fitting a leading edge circle according to the leading edge point set;

[0224] Fitting a trailing edge circle according to the trailing edge point set;

[0225] Taking the center of the leading edge circle as the center and 1.5 times the radius of the leading edge circle as the radius to draw a circle, obtaining a first concentric circle;

[0226] Taking the center of the trailing edge circle as the center and 1.5 times the radius of the trailing edge circle as the radius to draw a circle, obtaining a second concentric circle;

[0227] Determining a first intersection point of the first concentric circle and the mean camber line;

[0228] Determining a second intersection point of the second concentric circle and the mean camber line;

[0229] Determining a third intersection point of the first normal line and the suction side line and a fourth intersection point of the first normal line and the pressure side line, wherein the first normal line is the normal line passing through the first intersection point, the suction side line is the curve formed by the suction side point set, and the pressure side line is the curve formed by the pressure side point set;

[0230] Determining a fifth intersection point of the second normal line and the suction side line and a sixth intersection point of the first normal line and the pressure side line, wherein the second normal line is the normal line passing through the second intersection point;

[0231] Calculating the distance between the third intersection point and the fourth intersection point to obtain the leading edge thickness;

[0232] Calculating the distance between the fifth intersection point and the sixth intersection point to obtain the trailing edge thickness.

[0233] Optionally, in some alternative embodiments, generating a plurality of cross-sectional planes of the blade along the stacking axis includes:

[0234] Generating a plurality of cross-sectional planes of the blade at equal intervals along the stacking axis of the blade according to a preset distance, wherein one cross-sectional plane is generated at one interval.

[0235] Optionally, in some alternative embodiments, determining the blade profile line according to each of the cross-sectional planes includes:

[0236] For any cross-sectional plane, calculating the intersection line of the cross-sectional plane and a preset blade grid to obtain the corresponding blade profile line.

[0237] Optionally, in some alternative embodiments, calculating an intersection line between the cross-sectional plane and a preset blade grid for any cross-sectional plane to obtain a corresponding blade profile line includes:

[0238] For any cross-sectional plane, intercepting the intersection line between the cross-sectional plane and the preset blade grid from the preset blade grid to obtain a corresponding blade profile line, where one cross-sectional plane corresponds to one blade profile line, and the preset blade grid is a three-dimensional solid model pre-generated based on the blade.

[0239] A method for verifying geometric features of a blade includes:

[0240] Comparing the geometric features extracted above with a pre-established CAD model and generating a corresponding data monitoring report.

[0241] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses, electronic devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable devices generate means for implementing the functions specified in one Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0242] In a typical configuration, an electronic device includes one or more processors (CPUs), a memory, and a bus. The electronic device may also include an input / output interface, a network interface, etc.

[0243] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM), and / or non-volatile memory in the form of, for example, read-only memory (ROM) or flash memory (flash RAM). The memory includes at least one storage chip. The memory is an example of a computer-readable medium.

[0244] A computer-readable medium includes permanent and non-permanent, removable and non-removable media that can implement information storage by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tapes, magnetic tape disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to store information that can be accessed by a computing device. As defined herein, a computer-readable medium does not include transitory computer-readable media, such as modulated data signals and carrier waves.

[0245] In the description of the present invention, it should be understood that if terms such as "upper", "lower", "front", "rear", "left", and "right" are used to indicate the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated position or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0246] It should be noted that in this document, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. It should also be noted that the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent in such a process, method, commodity or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, commodity or device including the element.

[0247] Those skilled in the art should understand that the embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0248] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A method for extracting geometric features of a blade, characterized in that, Including: Generating a plurality of cross-sectional planes of the blade along the stacking axis; Determining the blade profile line of the blade according to each of the cross-sectional planes; Extracting geometric features of the blade according to the blade profile line, wherein the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

2. The method according to claim 1, wherein The extracting geometric features of the blade according to the blade profile line includes: Calculating the convex hull of the blade profile line, and calculating a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull; Calculating a mean camber line and a maximum thickness according to the suction side point set and the pressure side point set; Calculating a leading edge thickness and a trailing edge thickness according to the leading edge point set and the trailing edge point set.

3. The method according to claim 2, wherein The calculating the convex hull of the blade profile line and calculating a suction side point set, a pressure side point set, a leading edge point set, a trailing edge point set, and a chord line according to the convex hull includes: Using a convex hull algorithm to calculate the blade profile line to obtain a corresponding convex hull; Selecting two points with the largest adjacent distance in the convex hull as approximate chord line endpoints; For any one of the approximate chord line endpoints, fitting the approximate chord line endpoint and three blade profile points adjacent to the approximate chord line endpoint on the left and right by the least squares method to obtain a first fitting circle, wherein one approximate chord line endpoint corresponds to one first fitting circle, and the blade profile points are from a blade profile line point cloud, and the blade profile line point cloud is a set of blade profile points of the blade profile line; Traversing each point in the blade profile line point cloud to obtain points with a distance less than a preset threshold from the first fitting circle as a first point set; Using the least squares method to fit the first point set to obtain a second fitting circle, and iteratively fitting like this until the obtained point set no longer changes; Obtaining a leading edge point set and a trailing edge point set from the point set that no longer changes, and obtaining a suction side point set and a pressure side point set from points other than the point set that no longer changes; Using the least squares method to fit the leading edge point set and the trailing edge point set respectively to obtain a leading edge circle and a trailing edge circle; Calculating a common tangent of the leading edge circle and the trailing edge circle as the chord line.

4. The method according to claim 2, wherein The calculating a mean camber line and a maximum thickness according to the suction side point set and the pressure side point set includes: Respectively fitting the pressure side point set and the suction side point set to obtain corresponding B-spline curves; Calculating the intersection of the normal line of the B-spline curve corresponding to the pressure side point set and the normal line of the B-spline curve corresponding to the suction side point set; Calculating a first distance from the intersection to each of the pressure side point sets; Calculating a second distance from the intersection to each of the suction side point sets; Calculating the distance difference between the first distance and the second distance, and if the distance difference is less than a preset distance threshold, determining the corresponding intersection as a point on the mean camber line, and fitting to obtain the mean camber line in this way; Selecting the diameter of the inscribed circle with the largest radius as the maximum thickness, wherein the inscribed circle is a circle with a point on the mean camber line as the center and inscribed with both the B-spline curve corresponding to the pressure side point set and the B-spline curve corresponding to the suction side point set.

5. The method according to claim 2, characterized in that, The calculating a leading edge thickness and a trailing edge thickness according to the leading edge point set and the trailing edge point set includes: According to the set of leading edge points, a leading edge circle is fitted; According to the set of trailing edge points, a trailing edge circle is fitted; Taking the center of the leading edge circle as the center and 1.5 times the radius of the leading edge circle as the radius, a first concentric circle is drawn; Taking the center of the trailing edge circle as the center and 1.5 times the radius of the trailing edge circle as the radius, a second concentric circle is drawn; Determine the first intersection point of the first concentric circle and the mean camber line; Determine the second intersection point of the second concentric circle and the mean camber line; Determine the third intersection point of the first normal line and the suction side line and the fourth intersection point of the first normal line and the pressure side line, where the first normal line is the normal line passing through the first intersection point, the suction side line is the curve formed by the set of suction side points, and the pressure side line is the curve formed by the set of pressure side points; Determine the fifth intersection point of the second normal line and the suction side line and the sixth intersection point of the first normal line and the pressure side line, where the second normal line is the normal line passing through the second intersection point; Calculate the distance between the third intersection point and the fourth intersection point to obtain the leading edge thickness; Calculate the distance between the fifth intersection point and the sixth intersection point to obtain the trailing edge thickness.

6. The method according to claim 1, wherein Along the stacking axis, a plurality of cross-sectional planes of the blade are generated, including: Along the stacking axis of the blade, at a preset distance, a plurality of cross-sectional planes of the blade are equidistantly generated, where one cross-sectional plane is generated at one interval.

7. The method according to claim 1, characterized in that, According to each of the cross-sectional planes, determining the blade profile line of the blade includes: For any cross-sectional plane, calculate the intersection line of the cross-sectional plane and the preset blade grid to obtain the corresponding blade profile line.

8. The method according to claim 7, wherein For any cross-sectional plane, calculating the intersection line of the cross-sectional plane and the preset blade grid to obtain the corresponding blade profile line includes: For any cross-sectional plane, intercept the intersection line of the cross-sectional plane and the preset blade grid from the preset blade grid to obtain the corresponding blade profile line, where one cross-sectional plane corresponds to one blade profile line, and the preset blade grid is a three-dimensional solid model pre-generated based on the blade.

9. A method for verifying the geometric characteristics of a blade, characterized in that, Including: Compare the geometric features extracted from the above claims 1-8 with the pre-established CAD model and generate a corresponding data monitoring report.

10. A device for extracting geometric features of a blade, characterized in that, Including: A plane generation unit, a blade profile line obtaining unit, and a feature extraction unit; The plane generation unit is used to generate a plurality of cross-sectional planes of the blade along the stacking axis; The blade profile line obtaining unit is used to determine the blade profile line of the blade according to each of the cross-sectional planes; The feature extraction unit is used to extract the geometric features of the blade according to the blade profile line, where the geometric features include at least one of a chord line, a mean camber line, a maximum thickness, a leading edge thickness, and a trailing edge thickness.

11. A computer-readable storage medium having a program stored thereon, characterized in that, When the program is executed by a processor, it implements the method for extracting geometric features of a blade as described in any one of claims 1 to 8.

12. An electronic device, characterized in that, The electronic device includes at least one processor, at least one memory connected to the processor, and a bus; wherein, the processor and the memory communicate with each other through the bus; the processor is used to call the program instructions in the memory to execute the method for extracting geometric features of a blade as described in any one of claims 1 to 8.

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