Method for optimizing broken surface of three-dimensional model of vane pump

Abstract

According to the vane pump three-dimensional model broken surface optimization method provided by the invention, the broken surface in the vane pump three-dimensional model is identified based on the attribute leading diagram, and the base surface structure fitting is carried out according to the geometric type of each fragment in the broken surface, so that the broken surface in the vane pump three-dimensional model is effectively corrected. According to the method, the continuity information of the adjacent curved surfaces on the connecting edges is added in the attribute leading diagram, and the broken surfaces are identified according to the continuity information. According to the method, from the two perspectives of geometric features and topological features of the vane pump three-dimensional model, repair of the broken surface defects in the vane pump three-dimensional model is achieved under the condition that the overall structure of the vane pump three-dimensional model is complete.

Description

Technical Field

[0001] The invention belongs to the field of fluid machinery design, and in particular relates to a surface optimization method for a three-dimensional model of a vane pump. Background Art

[0002] As a general-purpose machine, the vane pump has been widely used in various sectors of the national economy. However, due to the complexity of the internal flow of the vane pump, there is no mature design and calculation theory so far. The existing vane pump design and calculation methods are still semi-empirical and semi-theoretical. Whether a high-performance vane pump can be designed depends largely on the experience of the designer. With the continuous improvement of modern science and technology, computer-aided design (CAD) and computational fluid dynamics (CFD) have appeared successively and are playing an increasingly important role in the modern pump industry. In the pre-processing process of CFD calculation, the quality of the vane pump three-dimensional model data plays a key role. The quality of the data determines whether the model information can be correctly and reasonably expressed when the data is converted between the CAD / CFD system, and whether it can meet the requirements of subsequent meshing and CFD calculation. Summary of the invention

[0003] In view of this, the present invention starts from the two perspectives of geometric characteristics and topological characteristics of the vane pump three-dimensional model, realizes the repair of the broken surface defects in the vane pump three-dimensional model while ensuring the overall structural integrity of the vane pump three-dimensional model, and establishes a broken surface optimization method for the vane pump three-dimensional model.

[0004] The present invention is achieved through the following technical solutions:

[0005] The broken surfaces in the three-dimensional model of the vane pump are identified based on the attribute connection diagram, and the base surface construction fitting is performed according to the geometric type of each fragment in the broken surface, so as to effectively correct the broken surfaces in the three-dimensional model of the vane pump.

[0006] Furthermore, the broken surface definition in the vane pump 3D model is established based on the geometric features. The specific steps are as follows:

[0007] (1) constructing surfaces with the same shape type, the same topological structure, similar curvature distribution, and position continuity, tangent direction continuity, and curvature continuity at the common boundary into a surface group F;

[0008] (2) There exists a surface S in the surface group F i If the ratio of the area of ​​to the area of ​​surface group F is less than the specified threshold, it is considered that there is a broken surface defect in surface group F.

[0009] Furthermore, before the broken surface recognition, it is necessary to repair the topological defects of the vane pump 3D model based on geometric reconstruction, including surface topology reconstruction, edge and point information reconstruction, and edge and point topology reconstruction.

[0010] Furthermore, the process of identifying the broken surfaces in the vane pump three-dimensional model based on the attribute connection graph is as follows:

[0011] A preliminary attribute connection graph G of the entire vane pump three-dimensional model is established; wherein the nodes in the attribute connection graph G represent the various surfaces in the vane pump three-dimensional model; the edges represent the shared boundaries between adjacent surfaces; and the attributes represent the geometric and topological properties of the nodes or edges.

[0012] Analyze the continuity of each adjacent node in G on the edge connecting the two nodes, and add continuity information to the connecting edge to obtain an extended attribute adjacency graph G' with edge attributes;

[0013] In the extended attribute adjacency graph G', the edges that do not satisfy the three continuity properties correspond to the defective edges of the broken surface. The edges that do not satisfy the three continuity properties are extracted from the extended attribute adjacency graph G' to obtain a non-repeating edge set E, and the set E is grouped to obtain n subsets of edges E1, E2, ..., E n ; Wherein, the three types of continuity include position continuity, tangent direction continuity, and curvature continuity;

[0014] Take the sub-edge sets E1, E2, ..., E n Construct the edge-induced subgraph set of G' {G'1, G'2, G'3, ..., G' n}, where subgraph G′ i , i = 1, 2, ..., n is the number of G's i Derived subgraphs; each subgraph corresponds to a broken surface defect on the surface of the vane pump three-dimensional model, the surface corresponding to each node in the subgraph is the broken surface, and the topological edge corresponding to each edge in the subgraph is the edge of the broken surface.

[0015] Furthermore, the three types of continuity are as follows:

[0016] Position continuity: refers to the continuity of the shared boundary of two faces in space;

[0017] Tangent direction continuity: refers to the continuity of the tangent direction of the shared boundary;

[0018] Curvature continuity: refers to the curvature continuity of shared boundaries.

[0019] Furthermore, the grouping rules of set E are as follows:

[0020] If there are two elements, edge e1 and edge e2, in E, and e1 and e2 have associated vertex sets Pe1 and Pe2 in G'; if Then e1 and e2 are considered to be the same group, denoted as G(e1)=G(e2);

[0021] For the edge elements in the same group, construct the edge subsets E1, E2, E3, ..., E1 that meet the following conditions: n ,

[0022]

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. This method can effectively identify the broken surfaces in the three-dimensional model of the vane pump.

[0025] 2. This method can be used to repair broken surfaces accurately and quickly.

[0026] 3. This method can effectively improve the quality of the vane pump three-dimensional model and provide high-quality data support for subsequent CFD calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of the vane pump three-dimensional model optimization method of the present invention;

[0028] Figure 2 Define schematic diagrams for the broken surfaces in the 3D model of the vane pump.

[0029] Figure 3 is the actual crushed surface of a vane pump;

[0030] Figure 4a It is an isolated point topological defect;

[0031] Figure 4b It is a hanging edge topological defect;

[0032] Figure 4c It is a topological defect of the hanging surface;

[0033] Figure 5a is a property adjacency graph of a three-dimensional model of a vane pump in an embodiment;

[0034] Figure 5b is an adjacency subgraph of the three-dimensional model of the vane pump in the embodiment;

[0035] Figure 6 It is an example of the broken surface of the three-dimensional model of the vane pump in the embodiment;

[0036] Figure 7 This is the repair effect of the broken surface of the vane pump three-dimensional model of the embodiment. DETAILED DESCRIPTION

[0037] This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and a specific implementation process, but the protection scope of the present invention is not limited to the following embodiments.

[0038] The present invention identifies the broken surfaces in the three-dimensional model of the vane pump based on the attribute connection graph, and performs base surface construction fitting according to the geometric type and parameters of each fragment in the broken surface, thereby effectively correcting the broken surfaces in the three-dimensional model of the vane pump.

[0039] The steps include:

[0040] a: Surface definition in the three-dimensional model of the vane pump based on geometric features

[0041] Establish the broken surface definition according to the geometric features of the vane pump CAD model. The specific steps are as follows:

[0042] (1) Surfaces S with the same shape type, topological structure, curvature distribution, and position continuity, tangent direction continuity, and curvature continuity at the common boundary are selected. i Constructed into a surface group F;

[0043] (2) There exists a subsurface S in the surface group F i The ratio of the area of ​​the surface group F to the area of ​​the surface group F is less than the specified threshold, then it is considered that there is a broken surface defect in the surface group F. This threshold is lowered at low specific speeds (specific speed n s ≤80) vane pump is taken as 0.1, medium specific speed (80 <n s ≤220) 0.2 in vane pump, high specific speed (n s >220) 0.25 in vane pump.

[0044] b: Repairing topological defects of the vane pump 3D model based on geometric reconstruction

[0045] Repair topological defects such as isolated points, hanging edges and hanging surfaces in the three-dimensional model of the vane pump; if there are no topological defects, proceed to the next step.

[0046] In step b, the specific topology defect repair steps are as follows:

[0047] (1) Surface topology reconstruction

[0048] Construct a new surface topology entity for the entire model and add corresponding topological relationships.

[0049] (2) Edge and point information reconstruction

[0050] Traverse all faces in the model, and perform Boolean intersection operations on faces with missing edge information and their adjacent faces, thereby generating n intersection lines and supplementing edge information. For faces with missing point information, perform Boolean operations on the intersection lines to determine the intersection point. Only when the distance between the intersection point of two intersection lines and other intersection lines is less than 10 -5 , is considered to be a valid intersection point;

[0051] (3) Edge and point topology reconstruction

[0052] According to the intersection line and vertex information obtained in (2), the edge and point construction operations are directly performed to obtain new edge and point topological entities.

[0053] c: Identifying the fragments of the vane pump 3D model based on the attribute adjacency graph

[0054] The entire vane pump three-dimensional model is traversed as a whole, and the surface nodes are directly established and connected to obtain a preliminary attribute connection graph G. Secondly, the continuity of each adjacent vertex in G on the corresponding edge is analyzed, and the corresponding continuity information is added to the corresponding edge in G, and the extended attribute adjacency graph G' with edge attributes is obtained. The edges that do not meet these three continuity in the extended attribute adjacency graph G' correspond to the defective edges of the broken surface. The extended attribute adjacency graph G' is traversed, and the edges that do not meet these three continuity are extracted to obtain a non-repeating edge set E, and the connecting edges in the set E are grouped. Then, with the sub-edge sets E1, E2, ..., E n Construct the edge-induced subgraph set of G' {G'1, G'2, G'3, ..., G' n}. Subgraph G′ i (i=1,2,…,n) is the G' from E i Derived subgraphs. Each subgraph corresponds to a broken surface defect on the model surface. The topological surface corresponding to each vertex in the subgraph is the broken surface, and the topological edge corresponding to each edge in the subgraph is the edge of the broken surface.

[0055] The calculation method of the continuity information in step c is as follows:

[0056] Positional continuity: There are adjacent faces F1 and F2. If these two faces have a common edge, then F1 and F2 are considered to be positionally continuous.

[0057] Tangent direction continuity: Under the premise of satisfying position continuity, there is a sampling point P at the common edge of adjacent faces F1 and F2. If the normal vector at point P satisfies is the error vector), then F1 and F2 are considered to have tangent direction continuity.

[0058] Curvature continuity: Under the premise of satisfying the tangent direction continuity, if the main direction (V max and V min) are collinear and have the same principal curvature, then F1 and F2 are considered to have curvature continuity.

[0059] The grouping rules for the adjacent edges in set E in step c are as follows:

[0060] If there are two elements, edge e1 and edge e2, in E, and e1 and e2 have associated vertex sets Pe1 and Pe2 in G'. It is considered that e1 and e2 are the same group, that is, G(e1)=G(e2).

[0061] For the edge elements in the same group, construct the edge subsets E1, E2, E3, ..., E1 that meet the following conditions: n

[0062]

[0063] d: Repair the broken surface of the vane pump 3D model based on the base surface structure

[0064] According to the geometric type and parameters of each fragment in the broken surface, a base surface is constructed that contains or is close to each fragment as much as possible. Then, the base surface is used for fitting to transform the scattered broken surfaces into a complete surface, thereby effectively correcting the broken surfaces.

[0065] The base surface is constructed by the construction operator. The radius R and the Z-axis direction of the coordinate system can be directly extracted from each broken surface, and the final parameter value is obtained by weighted average according to the relative area of ​​the broken surface. The corresponding angle, length constraint value and other parameters can be calculated by traversing the boundary contour line of the broken surface.

[0066] The details are as follows:

[0067] The plane uses cubic B-spline curves to interpolate the endpoints of all straight generatrixes on all surfaces to generate n baselines of the surface; by generating more data points on the n baselines, the density of data points is controlled. When the density of data points reaches the preset threshold, a parameterized plane is directly generated on the point grid formed by these data points.

[0068] The construction operator of the cylindrical surface is F = f(A, R, H1, H2, α1, ɑ2), where A is the local coordinate system O-XYZ, R is the radius of the cylindrical surface, H1 and H2 are the starting and ending height values ​​of the cylindrical surface along the axial direction, and α1 and α2 are the starting and ending center angles of the cylindrical surface.

[0069] The construction operator of the cone surface is F = f(A, R, θ, H1, H2, α1, ɑ2), where A is the local coordinate system O-XYZ, R is the radius of the cone base, θ is the semi-apex angle of the cone surface, H1 and H2 are the starting and ending height values ​​of the cone surface along the axis, and α1 and α2 are the starting and ending center angles of the cone surface.

[0070] The construction operator of the sphere is F=f(A, α1, α2, β1, β2, R), where f is the construction operator of the sphere, A is the local coordinate system O-XYZ, α1 and α2 are the starting rotation angle and the ending rotation angle of the circular meridian arc, β1 and β2 are the starting angle and the ending angle of the circular meridian arc, and R is the radius of the sphere.

[0071] The construction operator of the torus is F = f(A, α1, α2, β1, β2, R1, R2), where f is the construction operator of the torus, A is the local coordinate system O-XYZ, the rotation axis is the Z axis, α1 and α2 are the starting and ending angles of the torus meridian arc, β1 and β2 are the starting and ending angles of the torus meridian arc, and R l is the radius of the meridian arc, and R2 is the distance from the center of the meridian arc to the rotation axis.

[0072] The construction operator of the rotation surface is F=f(A, L, α1, α2), where A is the local coordinate system O-XYZ, the rotation axis is the Z axis, L is the contour line of the rotation surface, and α1 and α2 are the starting and ending angles of the contour line rotation, respectively.

[0073] The construction operator of the stretched surface is F=f(v, L, H1, H2), where f is the construction operator of the stretched surface, v is the stretching direction, H1 is the starting length along the v direction, and H2 is the ending length along the v direction.

[0074] The following is further described in conjunction with the accompanying drawings. The present invention is a method for optimizing the surface of a three-dimensional model of a vane pump based on a CAD platform.

[0075] With a specific speed n s Taking the vane pump with a diameter of 118 as an example, its main parameters are: impeller outlet width b2=30mm, impeller outlet diameter D2=315mm, base circle diameter D3=342, inlet width b3=60.

[0076] Step 1: Establish the surface definition in the vane pump 3D model based on geometric features

[0077] For the vane pump three-dimensional model M of the embodiment, the broken surface definition is established according to the geometric features of the vane pump three-dimensional model. The broken surface definition is established to more accurately represent and analyze the local features of complex geometric bodies. For a mechanical part such as a vane pump with a complex geometric structure, the calculation accuracy and efficiency can be improved through the broken surface definition. The specific steps are as follows:

[0078] (1) Multiple surfaces Si with the same shape type, the same topological structure, similar curvature distribution, and positional continuity, tangent direction continuity, and curvature continuity at the common boundaries generated by the geometric contact or connection relationship between adjacent surfaces are constructed into a surface group F.

[0079] The same shape type means that these surfaces have the same basic features and forms in terms of geometry, for example, they may all be planes, spheres, cylinders, etc. The same topology means that the connection relationships and boundary conditions of these surfaces are the same. Specifically, the topology includes the number of boundaries of the surface, the connectivity of the surface, the number of holes on the surface, etc.

[0080] (2) If the ratio of the area of ​​the sub-surfaces in the surface group F to the area of ​​the surface group F is less than a specified threshold, it is considered that there is a broken surface defect in the surface group F. The vane pump is a medium specific speed vane pump, and the threshold is selected as 0.2.

[0081] Step 2: Repair the topological defects of the vane pump 3D model based on geometric reconstruction

[0082] The embodiment is subjected to topological defect repair, and the repaired topological defects include isolated points (such as Figure 4a As shown), hanging edge (as shown Figure 4b as shown) and overhanging surface (as shown Figure 4c shown).

[0083] Repair according to the following method:

[0084] (1) Surface topology reconstruction

[0085] Constructing new surface topological entities for the overall model and adding corresponding topological relationships is the basis of the entire process, defining the surface topological structure of the model and laying the foundation for the subsequent reconstruction of edges and points.

[0086] (2) Edge and point information reconstruction

[0087] Traverse all faces in the model, and perform Boolean intersection operations on faces with missing edge information and their adjacent faces to generate n intersection lines to supplement edge information. For missing point information, perform Boolean operations on the intersecting lines between faces to determine the intersection point. Only when the distance between the intersection point of two intersecting lines and other intersection lines is less than 10 -5 , is considered to be a valid intersection point;

[0088] (3) Edge and point topology reconstruction

[0089] According to the intersection line and vertex information obtained in (2), the edge and point construction operations are directly performed to obtain new edge and point topological entities.

[0090] Step 3: Identify the fragments of the vane pump 3D model based on the attribute adjacency graph

[0091] The embodiment is traversed as a whole, and the face nodes are directly established and connected to obtain a preliminary attribute adjacency graph G. In this adjacency graph G:

[0092] Nodes represent topological surfaces (i.e., surfaces or patches) in the model. Each node represents a specific surface and contains the geometry and topological information of the surface.

[0093] Edges represent shared boundaries between adjacent faces. Edges connect two adjacent face nodes, reflecting the topological relationship between them.

[0094] Attributes represent the geometric and topological properties of nodes and edges. For example, the attributes of nodes may include the curvature and area of ​​faces; the attributes of edges may include the length of common boundaries, curvature continuity, positional continuity, and tangent direction continuity.

[0095] Secondly, the continuity of each adjacent vertex in G on the corresponding edge is analyzed, and the corresponding continuity information is added to the corresponding edge in G, and the extended attribute adjacency graph G' with edge attributes is obtained. The adjacent vertices refer to two face nodes directly connected by an edge in the adjacency graph G. These vertices represent adjacent topological faces, and the corresponding edge refers to the edge connecting two adjacent vertices, that is, the shared boundary between two adjacent topological faces. In the model, this edge is actually the common boundary of the two faces.

[0096] In the extended attribute adjacency graph G', the edges that do not satisfy the three continuity conditions correspond to the defective edges of the broken surface. By traversing the extended attribute adjacency graph G' and extracting the edges that do not satisfy the three continuity conditions, a non-repeating edge set E can be obtained. The reasons why these edges correspond to the defective edges of the broken surface are:

[0097] Positional continuity (G0): If the shared boundary of two faces is not continuous in space (i.e., there is a gap or overlap), it indicates that there are geometric defects or inconsistencies in the connection of these faces.

[0098] Tangent direction continuity (G1): If the tangent direction of a shared boundary is not continuous (i.e., the normal vectors are inconsistent), this will result in poor smooth transition between adjacent faces at the boundary, which is usually a sign of a broken surface defect.

[0099] Curvature continuity (G2): If the curvature of a shared boundary is discontinuous (i.e., the second-order derivatives are inconsistent), the surfaces of adjacent faces will have obvious curvature changes at the boundary, indicating the presence of a broken surface defect.

[0100] And group the edges adjacent to each face node in set E to obtain n edge subsets E1, E2, ..., E n . Then with the sub-edge sets E1, E2, ..., E n Construct the edge-induced subgraph set of G' {G'1, G'2, G'3, ..., G' n}. Subgraph G′ i(i=1, 2, ..., n) is a subgraph of G' derived from Ei. Each subgraph corresponds to a broken surface defect on the model surface. The topological surface corresponding to each vertex in the subgraph is the broken surface, and the topological edge corresponding to each edge in the subgraph is the edge of the broken surface.

[0101] The calculation method of continuity information in step 3 is as follows:

[0102] Positional continuity: There are adjacent faces F1 and F2. If these two faces have a common edge, then F1 and F2 are considered to be positionally continuous.

[0103] Tangent direction continuity: Under the premise of satisfying position continuity, there is a sampling point P at the common edge of adjacent faces F1 and F2. If the normal vector at point P satisfies is the error vector), then F1 and F2 are considered to have tangent direction continuity, where represents the tangent vector of face F1, Represents the tangent vector of face F2.

[0104] Curvature continuity: Under the premise of satisfying the tangent direction continuity, if the main direction (V max and V min ) are collinear and have the same principal curvature, then F1 and F2 are considered to have curvature continuity.

[0105] In step 3, the grouping rules for each adjacent edge in set E are as follows. The logic behind the grouping rules is to group related edges together to form sub-edge sets, which represent partial topological structures with certain common characteristics.

[0106] If there are two elements, edge e1 and edge e2, in E, and e1 and e2 exist in G' with all vertex sets Pe1 and Pe2 associated with the edge. Then e1 and e2 are considered to be the same group, and are denoted as G(e1)=G(e2).

[0107] For the edge elements in the same group, construct the edge subsets E1, E2, E3, ..., E1 that meet the following conditions: n

[0108]

[0109] (3)G(e1)≠G(e s ), (e1∈E i , e s ∈E j ;i≠j)

[0110] The characteristic edge set of the attribute adjacency graph of this embodiment is E={e 12 、e 23 、e34 、e 14 、e 56 、e 67 、e 57}, the schematic diagram is as follows Figure 5a As shown. Based on the above rules, after grouping its characteristic edge set, we can get the sub-edge set E1 = {e 12 、e 23 、e 34 、e 14} and E2={e 56 、e 67 、e 57}, then its derived subgraph is as follows Figure 5b

[0111] Step 4: Repair the broken surface of the vane pump 3D model based on the base surface structure

[0112] According to the geometric type and parameters of each fragment in the broken surface in the embodiment, a base surface is constructed that contains or is close to each fragment as much as possible. Then, the base surface is used for fitting to transform the scattered broken surface into a complete curved surface, thereby effectively correcting the broken surface.

[0113] For different types of broken surfaces, the base surface construction includes plane, cylinder, cone, torus, sphere, revolution surface, and stretch surface. The specific construction operators are as follows:

[0114] The plane uses cubic B-spline curves to interpolate the endpoints of all straight generatrixes on all surfaces to generate n baselines of the surface; by generating more data points on the n baselines, the density of data points is controlled. When the density of data points reaches the preset threshold, a parameterized plane is directly generated on the point grid formed by these data points.

[0115] The construction operator of the cylindrical surface is F = f(A, R, H1, H2, α1, ɑ2), where A is the local coordinate system O-XYZ, R is the radius of the cylindrical surface, H1 and H2 are the starting and ending height values ​​of the cylindrical surface along the axial direction, and α1 and α2 are the starting and ending center angles of the cylindrical surface.

[0116] The construction operator of the cone surface is F = f(A, R, θ, H1, H2, α1, ɑ2), where A is the local coordinate system O-XYZ, R is the radius of the cone base, θ is the semi-apex angle of the cone surface, H1 and H2 are the starting and ending height values ​​of the cone surface along the axis, and α1 and α2 are the starting and ending center angles of the cone surface.

[0117] The construction operator of the sphere is F=f(A, α1, α2, β1, β2, R), where f is the construction operator of the sphere, A is the local coordinate system O-XYZ, α1 and α2 are the starting rotation angle and the ending rotation angle of the circular meridian arc, β1 and β2 are the starting angle and the ending angle of the circular meridian arc, and R is the radius of the sphere.

[0118] The construction operator of the torus is F = f(A, α1, α2, β1, β2, R1, R2), where f is the construction operator of the torus, A is the local coordinate system O-XYZ, the rotation axis is the Z axis, α1 and α2 are the starting and ending angles of the torus meridian arc, β1 and β2 are the starting and ending angles of the torus meridian arc, and R l is the radius of the meridian arc, and R2 is the distance from the center of the meridian arc to the rotation axis.

[0119] The construction operator of the rotation surface is F=f(A, L, α1, α2), where A is the local coordinate system O-XYZ, the rotation axis is the Z axis, L is the contour line of the rotation surface, and α1 and α2 are the starting and ending angles of the contour line rotation, respectively.

[0120] The construction operator of the stretched surface is F=f(v, L, H1, H2), where f is the construction operator of the stretched surface, v is the stretching direction, H1 is the starting length along the v direction, and H2 is the ending length along the v direction.

[0121] The results before and after the repair of this embodiment are as follows Figure 6 and Figure 7 shown.

Claims

1. A method for optimizing the surface of a three-dimensional model of a vane pump, characterized in that: The broken surfaces in the three-dimensional model of the vane pump are identified based on the attribute connection diagram, and the base surface construction fitting is performed according to the geometric type of each fragment in the broken surface, so as to effectively correct the broken surfaces in the three-dimensional model of the vane pump.

2. A vane pump three-dimensional model surface optimization method according to claim 1, characterized in that: The broken surface definition in the vane pump 3D model is established based on geometric features. The specific steps are as follows: (1) constructing surfaces with the same shape type, the same topological structure, similar curvature distribution, and position continuity, tangent direction continuity, and curvature continuity at the common boundary into a surface group F; (2) There exists a surface S in the surface group F i If the ratio of the area of ​​to the area of ​​surface group F is less than the specified threshold, it is considered that there is a broken surface defect in surface group F.

3. A vane pump three-dimensional model surface optimization method according to claim 1 or 2, characterized in that: Before the broken surface recognition, it is necessary to repair the topological defects of the vane pump 3D model based on geometric reconstruction, including surface topology reconstruction, edge and point information reconstruction, and edge and point topology reconstruction.

4. A vane pump three-dimensional model surface optimization method according to claim 3, characterized in that: The process of identifying the broken surfaces in the vane pump 3D model based on the attribute connection diagram is as follows: A preliminary attribute connection graph G of the entire vane pump three-dimensional model is established; wherein the nodes in the attribute connection graph G represent the various surfaces in the vane pump three-dimensional model; the edges represent the shared boundaries between adjacent surfaces; and the attributes represent the geometric and topological properties of the nodes or edges. Analyze the continuity of each adjacent node in G on the edge connecting the two nodes, and add continuity information to the connecting edge to obtain an extended attribute adjacency graph G' with edge attributes; In the extended attribute adjacency graph G', the edges that do not satisfy the three continuity properties correspond to the defective edges of the broken surface. The edges that do not satisfy the three continuity properties are extracted from the extended attribute adjacency graph G' to obtain a non-repeating edge set E, and the set E is grouped to obtain n subsets of edges E1, E2, ..., E n ; Wherein, the three types of continuity include position continuity, tangent direction continuity, and curvature continuity; Take the sub-edge sets E1, E2, ..., E n Construct the edge-induced subgraph set of G' {G'1, G'2, G'3, ..., G' n }, where subgraph G i ′, i = 1, 2, ..., n is the number of G's i Derived subgraphs; each subgraph corresponds to a broken surface defect on the surface of the vane pump three-dimensional model, the surface corresponding to each node in the subgraph is the broken surface, and the topological edge corresponding to each edge in the subgraph is the edge of the broken surface.

5. A method for optimizing the surface of a vane pump three-dimensional model according to claim 4, characterized in that: The three types of continuity are as follows: Position continuity: refers to the continuity of the shared boundary of two faces in space; Tangent direction continuity: refers to the continuity of the tangent direction of the shared boundary; Curvature continuity: refers to the curvature continuity of shared boundaries.

6. A method for optimizing the surface of a vane pump three-dimensional model according to claim 5, characterized in that: The grouping rules of set E are as follows: If there are two elements, edge e1 and edge e2, in E, and e1 and e2 have associated vertex sets Pe1 and Pe2 in G'; if Then e1 and e2 are considered to be the same group, denoted as G(e1)=G(e2); For the edge elements in the same group, construct the edge subsets E1, E2, E3, ..., E1 that meet the following conditions: n , G(e1)≠G(e s ),(e1∈E i ,have been s ∈E j ;i≠j)。

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