CN109086492B - Wire frame representation and deformation method and system for three-dimensional model of vehicle body structure - Google Patents
Wire frame representation and deformation method and system for three-dimensional model of vehicle body structure Download PDFInfo
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Abstract
The invention provides a wire frame representation and deformation method and system for a three-dimensional model of a vehicle body structure. The method comprises the following steps: extracting sub-graph models of beam members and plate members in a three-dimensional model of a vehicle body to be analyzed; assembling the extracted sub-graph models according to the connection relation of the beams and the plate members in the vehicle body structure to obtain an initial graph model corresponding to the vehicle body structure; simplifying the initial graph model into a wire frame model; finishing the deformation of the wire frame model by a grid deformation method based on the Laplace coordinate; and finishing the deformation of the three-dimensional model of the vehicle body structure based on a deformation method of the radial basis function. The method can quickly acquire the adjusted finite element model in the process of optimization design of the vehicle body structure, avoids the time-consuming and labor-consuming behaviors of manual re-modeling by professional technicians, and can be widely popularized in the field of vehicle body structure design on the basis of the reason.
Description
Technical Field
The invention relates to the field of vehicle body structure design, in particular to a method and a system for representing and deforming a wire frame of a three-dimensional model of a vehicle body structure.
Background
With the increasing requirements for light weight and safety, how to improve the structural performance indexes of the designed vehicle body structure becomes a key problem of vehicle body design. The above problems can be effectively solved by adopting an optimal design technology. In the design of structure optimization, it is generally required to provide multiple sets of models to calculate the sensitivity or shape update of the structure.
The vehicle body structure is generally subjected to structural mechanics simulation analysis by adopting a finite element analysis model or an isogeometric analysis model. In order to update the analysis model, the shape change of the whole vehicle structure analysis model is mainly obtained by manual modeling at the present stage. Since both types of models have complex geometries, manual modeling not only takes a lot of time, but also requires a technician to have a rich modeling experience.
The other method adopts a pre-parameterized CAD model to realize the change of the geometric shape of the whole vehicle, and then obtains a finite element mesh suitable for structural analysis according to an automatic mesh generation method. However, the automatic generation of mesh models from geometrically complex CAD models presents robustness problems.
Disclosure of Invention
In light of the above-mentioned technical problems, a wire frame representation and deformation method for a three-dimensional model of a vehicle body structure is provided to quickly obtain an adjusted finite element model. The technical means adopted by the invention are as follows:
a wire frame representation and deformation method of a three-dimensional model of a vehicle body structure comprises the following steps:
s1, extracting sub-graph models of a beam member and a plate member in a three-dimensional model of a vehicle body to be analyzed;
s2, assembling the extracted sub-graph models according to the connection relation of beams and plate members in the vehicle body structure to obtain an initial graph model corresponding to the vehicle body structure;
s3, simplifying the initial graph model into a wire frame model, wherein the wire frame model consists of a vertex set of the initial graph model and a straight line segment set representing vertex connection relation;
s4, completing the deformation of the wire frame model by a grid deformation method based on Laplace coordinates;
and S5, inputting the wire frame model before and after deformation through a deformation method based on the radial basis function, and completing the deformation of the three-dimensional model of the vehicle body structure.
Further, in step S1, a sub-graph model of the beam member is extracted automatically or manually, wherein the center line of the extracted beam member satisfies the following relationship:
each beam member has a center line corresponding to the beam member, and the center line should penetrate through the beam member and pass through the center point of each cross section of the member;
the connecting positions of the beam members are composed of intersection points of a plurality of central lines corresponding to the beam members;
and adopting a broken line segment to represent the central line, and obtaining a group of vertex sets and straight edge sets connecting the vertices.
Further, in step S1, extracting the sub-graph model of the plate member includes:
s101, extracting a boundary curve of a plate component model;
s102, sampling type value points on the boundary curve, and calculating through a K-MEANS algorithm to obtain sampling points inside the plate member;
s103, taking sampling type value points on the boundary curve and in the plate member as input of a Voronoi division method, and dividing the area where the plate member is located to obtain a plurality of sub-areas;
and S104, connecting sampling type value points corresponding to adjacent sub-regions by adopting a straight edge according to the adjacency relation of the sub-regions obtained by subdivision to form a subgraph corresponding to the plate member.
Further, in steps S2 and S3, a wire frame model is constructed as follows:
s21, establishing a connection relation between a subgraph of the beam member and an inner vertex of a subgraph of the plate member adjacent to the subgraph according to the adjacent relation of the beam and the plate member, and assembling the subgraph of the beam member and the subgraph of the plate member adjacent to the subgraph;
s22, assembling all the sub-graphs to obtain an initial graph model;
s31, respectively classifying vertexes in the initial graph model, wherein intersection points of three or more members are secondary vertexes, vertexes forming the convex hull of the initial wire frame model are primary vertexes, and other vertexes are zero-order vertexes;
s32, setting a length threshold value, simultaneously ensuring that any straight edge at most contains one secondary vertex, and simplifying an initial graph model by the following method:
s321, if the length of a straight edge is greater than the threshold value, no operation is performed;
if the length of a certain straight edge is not greater than the threshold value, the following judgment is carried out:
when the two vertexes connected by the straight edge have the same grade, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the average value of the two vertexes connected by the straight edge,
when the two connected vertexes of the straight edge are different in grade, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the same as the position of a vertex with a higher grade in the straight edge;
s322, connecting adjacent vertexes of the two vertexes of the straight edge with the introduced new vertex;
and S323, repeating the steps S321 and S322 until the length of the straight edge is smaller than the threshold value, and obtaining a simplified initial graph model, namely a wire frame model.
Further, in step S4, a deformed wire frame model is obtained by the following method:
s41, dividing the driven subgraph into a plurality of flow pattern subgraphs according to the vehicle body structural member corresponding to each vertex in the driven subgraph and the flow pattern structure of the driven subgraph,
wherein the driven sub-graph is the other regions except the deformation region and the fixed region in the wire-frame model,
the flow pattern structure comprises a beam component subgraph as a first-order flow pattern and a plate component subgraph as a second-order flow pattern;
s42, calculating the deformation of each flow pattern subgraph forming the driven subgraph by a grid deformation method of Laplace coordinates,
wherein L is k Laplace operator for the k-order flow pattern, δ = L k v is Laplace coordinate of each vertex v in the k-order flow pattern subgraph, and (i, j) represents the vertex v i And v j The set C is a vertex set shared by the slave subgraphs, the deformed subgraphs and the fixed subgraphs, wherein the vertex set is shared by the different flow pattern subgraphs;
s43, assembling the deformed deformation subgraph, the driven subgraph and the fixed subgraph according to the shared vertex to obtain a deformed wire frame model.
Further, the step S5 is a method for deforming the three-dimensional model of the vehicle body structure as follows:
s51, all vertexes { v ] in the wire-frame model before deformation, namely the wire-frame model in the step S3 i And (5) as a base point of the radial basis function deformation method, calculating deformation vectors of vertexes of the wire frame model before and after deformation:
d i =v i ′-v i ；
s52, calculating a deformation vector of the arbitrary space point x by the following formula:
wherein, | x-v i L is from space point x to RBF base point v i Has a Euclidean distance of phi as a radial basis function, w i For base point v of RBF i The weight coefficients of the radial basis functions are determined,
calculating the weight coefficient:
let x = v j To obtain d j =∑ i w i φ(|v j -v i |)=∑ i w i φ ji
Wherein v is j Is a base point of a certain RBF. Therefore, the weight coefficient w at each RBF base point can be obtained according to the above formula i ；
And S53, substituting the grid vertex of the three-dimensional model into the deformation vector calculation formula in S52, calculating the deformation vector of the three-dimensional model vertex, and adding the deformation vector to the grid vertex to obtain the deformation result of the three-dimensional model.
The invention also provides a wire frame representation and deformation system of the three-dimensional model of the vehicle body structure, which comprises the following components:
the sub-graph model building unit is used for extracting sub-graph models of beam members and plate members in the three-dimensional model of the vehicle body to be analyzed;
the initial graph model building unit is used for assembling the extracted sub-graph models to build an initial graph model;
the wire frame model building unit is used for simplifying and recombining the vertex set and the straight-line segment set of the initial graph model to build a wire frame model;
the wire frame model deformation unit is used for carrying out deformation processing on the wire frame model;
and a vehicle body structure three-dimensional model deformation unit.
According to the invention, the beam members and the plate members in the graph model are recombined and simplified into the wire frame model, and the three-dimensional model of the vehicle body structure is driven by the wire frame model to realize the deformation process of the finite element model.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a flow chart of a wire frame representation and deformation method of a three-dimensional model of a vehicle body structure according to the present invention.
FIG. 2 is a block diagram of a wire frame representation and deformation system for a three-dimensional model of a vehicle body structure according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
As shown in fig. 1, a method for representing and deforming a wire frame of a three-dimensional model of a vehicle body structure includes the following steps:
s1, extracting sub-graph models of a beam member and a plate member in a three-dimensional model of a vehicle body to be analyzed;
s2, assembling the extracted sub-graph models according to the connection relation of beams and plate members in the vehicle body structure to obtain an initial graph model corresponding to the vehicle body structure;
s3, simplifying the initial graph model into a wire frame model, wherein the wire frame model consists of a vertex set of the initial graph model and a straight line segment set representing vertex connection relation;
s4, completing the deformation of the wire frame model by a grid deformation method based on Laplace coordinates;
and S5, inputting the wire frame model before and after deformation through a deformation method based on the radial basis function, and completing the deformation of the three-dimensional model of the vehicle body structure.
The wire frame model is represented by a graph model and is marked as G = { V, E }, wherein V is a vertex set of the graph model, E represents a connection relation of each vertex in V, and two adjacent vertices are connected by adopting a straight line segment.
Vehicle body structures are generally composed of beam, panel members. Aiming at the characteristic, firstly, sub-graph models corresponding to the beam and the plate component are respectively extracted, and then the extracted sub-graph models are assembled according to the connection relation of the components to obtain a graph model corresponding to the vehicle body structure.
In step S1, a sub-graph model of the beam member is extracted in an automatic or manual manner, wherein a center line of the extracted beam member satisfies the following relationship:
each beam member has a center line corresponding to the beam member, and the center line penetrates the beam member as far as possible and passes through the center point of each cross section of the member;
the connection positions of the plurality of beam members, i.e., joint portions, are represented by intersections of a plurality of center lines corresponding to the beam members;
and adopting a broken line segment to represent the central line, and obtaining a group of vertex sets and straight edge sets connecting the vertices.
The polyline segments represent control polygons that include, but are not limited to, polyline segments obtained by directly sampling the centerline, parametric curves used to approximate the centerline. The user may further insert new vertices for the polyline segment according to design requirements.
Obtaining a set of vertex sets V = { V = { (vi) } i And a set of straight edges E = { E } connecting vertices ij And (6) forming a subgraph of the corresponding beam member.
A beam member subgraph is in a first-order flow pattern, namely, any vertex in the subgraph is required to have two adjacent points except for a boundary point, and the two adjacent points are not mutually adjacent.
The sub-graph model of the extraction plate member comprises:
s101, extracting a boundary curve of a plate component model;
s102, sampling M type value points on a boundary curve, and calculating by a K-MEANS algorithm to obtain N sampling points inside the plate member;
s103, dividing the area of the plate member by taking M sampling type value points on the boundary curve and N sampling type value points in the plate member as input of a Voronoi division method to obtain a plurality of sub-areas S i ；
S i ={x|d(x,v i )＜d(x,v j ),i≠j} (1)
In the formula (I), the compound is shown in the specification,
d(x,v i ) Is the Euclidean distance between the two points x and v, v i And v j For any two sampling type value points
And S104, connecting sampling type value points corresponding to adjacent sub-regions by adopting a straight edge according to the adjacency relation of the sub-regions obtained by subdivision to form a subgraph corresponding to the plate member.
And selecting proper M and N values to ensure that the subgraph model of the plate member model is a second-order flow pattern.
In steps S2 and S3, a wire-frame model is constructed as follows:
and S21, a subgraph of a certain beam component is Gb, and a subgraph of an adjacent plate component is Gp. And establishing a connection relation of inner vertexes of the sub-graphs Gb and Gp according to the adjacent relation of the beams and the plate members, and assembling the Gb and the Gp.
And S22, assembling all the sub-graphs to obtain an initial graph model G, wherein the graph model can effectively represent the connection relation of all the components in the vehicle body structure.
The resulting graph model G is further simplified and referred to as a wire-frame representation for subsequent calculations.
First, the vertices in the graph model are classified, wherein the intersections of a plurality of (three or more) members are secondary vertices, the vertices constituting the convex hull of the initial wire-frame model are called primary vertices, and the remaining vertices are called zero-order vertices. It should be ensured that any straight edge contains at most only one secondary vertex.
Next, the graph model G is simplified according to the following rule
1) A user designates a length threshold T, and if the length of a certain straight edge is greater than the threshold T, no operation is performed;
2) Otherwise:
2a) If the two connected vertexes of the straight edge have the same grade, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the average value of the two connected vertexes of the straight edge;
2b) Otherwise, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the same as the position of a vertex with higher grade in the straight edge;
2c) Wherein, introducing a new vertex and changing the connection relation of the wire frame model according to the following procedures: and connecting the adjacent vertex of the two vertexes of the straight edge with the introduced new vertex.
3) And repeating the steps until the length of the straight edge is less than T.
Finally, the simplified graph model G is represented as a simplified wire frame of the three-dimensional model.
In step S4, a deformed wire frame model is obtained by the following method:
a user needs to interactively specify a deformation region and a fixed region in the wire-frame model, and the remaining region is a driven region and is subjected to shape change according to the deformation region and the fixed region. Respectively calling deformation and fixed regions in the wire-frame model as deformation and fixed subgraphs, wherein the regions are represented by graph models formed by vertexes and straight edges; the driven area is called a driven graph.
And solving the deformation of the driven subgraph according to the deformation subgraph and the fixed subgraph to obtain the integral deformation of the wire-frame model. The deformation of the slave graph is calculated as follows:
1) And dividing the driven subgraph into a plurality of flow subgraphs according to the corresponding vehicle body structural parts of all vertexes in the driven subgraph and the affiliated flow pattern structures (the beam component is in a first-order flow pattern, and the plate component is in a second-order flow pattern).
2) And calculating the deformation of each flow pattern subgraph forming the driven subgraph by adopting a grid deformation method based on Laplace coordinates, wherein the deformation is described as the following formula:
wherein L is k Laplace operator for the k-order flow pattern, δ = L k v is the Laplace coordinate of each vertex v in the k-order flow pattern subgraph. And establishing the incidence relation of the graph model vertex by adopting a Laplace operator and transferring deformation.(i, j) denotes the vertex v i And v j The shared vertexes of different flow type subgraphs are required to have no difference in position. This is because adjacent flow-type subgraphs must have shared vertices connecting them, and it is required to maintain the consistency of the shared vertex positions in the process of solving from the deformation of the subgraph. The set C is a vertex set shared by the driven subgraph and the deformation subgraph and the fixed subgraph, so that the vertex shared by the driven subgraph and the deformation subgraph and the fixed subgraph is used as a deformation constraint condition, and the deformation result is ensured to meet the design requirement of the deformation of the vehicle body structure.
3) And assembling the deformed deformation subgraph, the driven subgraph and the fixed subgraph according to the shared vertex to obtain a deformed wire frame model.
S5, the deformation method of the three-dimensional model of the vehicle body structure comprises the following steps:
s51, all vertexes { v ] in the wire-frame model G before deformation i Using the vector as the base point of the RBF deformation method, and calculating the deformation vector d of each vertex of the wire frame model before and after deformation i =v i ′-v i 。
S52, calculating the deformation vector of any space point x according to the RBF method according to the following formula:
wherein, | x-v i L is from space point x to RBF base point v i Has a Euclidean distance of phi as a radial basis function, w i For base point v of RBF i The weight coefficients of the radial basis functions. Alternative RBF basis functions are common knowledge and can be found in the literature.
dland,2006)。
3) Since the weight coefficients are unknown, interpolation calculation according to the RBF method is required. Let x = v j There is a following formula established,
wherein v is j Base point for a certain RBF. Therefore, the weight coefficient w at each RBF base point can be obtained according to the above formula i 。
And (4) bringing the mesh vertex of the three-dimensional model into a formula, and calculating to obtain the deformation vector of the three-dimensional model vertex. By adding these deformation vectors to the mesh vertices, the deformation results of the three-dimensional model can be obtained.
A wire frame representation and deformation system for a three-dimensional model of a vehicle body structure, comprising:
the sub-graph model building unit is used for extracting sub-graph models of beam members and plate members in the three-dimensional model of the vehicle body to be analyzed;
the initial graph model building unit is used for assembling the extracted sub-graph models to build an initial graph model;
the line frame model building unit is used for simplifying and recombining the vertex set and the straight line segment set of the initial graph model to build a line frame model;
the wire frame model deformation unit is used for carrying out deformation processing on the wire frame model;
and a vehicle body structure three-dimensional model deformation unit.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and these modifications or substitutions do not depart from the spirit of the corresponding technical solutions of the embodiments of the present invention.
Claims (3)
1. A wire frame representation and deformation method of a three-dimensional model of a vehicle body structure is characterized by comprising the following steps: the method comprises the following steps:
s1, extracting sub-graph models of a beam member and a plate member in a three-dimensional model of a vehicle body to be analyzed;
s2, assembling the extracted sub-graph models according to the connection relation of beams and plate members in the vehicle body structure to obtain an initial graph model corresponding to the vehicle body structure;
s3, simplifying the initial graph model into a wire-frame model, wherein the wire-frame model is composed of a vertex set of the initial graph model and a straight line segment set representing vertex connection relations;
s4, completing the deformation of the wire frame model by a grid deformation method based on Laplace coordinates;
s5, inputting the wire frame model before and after deformation through a deformation method based on a radial basis function, and completing deformation of the three-dimensional model of the vehicle body structure;
the step S1 specifically includes: s101, extracting a boundary curve of a plate component model;
s102, sampling M type value points on a boundary curve, and calculating by a K-MEANS algorithm to obtain N sampling points inside the plate member;
s103, dividing the area of the plate member by taking M sampling type value points on the boundary curve and N sampling type value points in the plate member as input of a Voronoi division method to obtain a plurality of sub-areas S i ；
S i ＝{x|d(x,v i )<d(x,v j ),i≠j} (1)
In the formula (I), the compound is shown in the specification,
d(x,v i ) Is the Euclidean distance between the two points x and v, v i And v j Any two sampling type value points are adopted;
s104, according to the adjacency relation of the sub-regions obtained by subdivision, connecting sampling type value points corresponding to the adjacent sub-regions by adopting straight edges to form sub-images corresponding to the plate members;
selecting proper M and N values to ensure that a subgraph model of the plate member model is a second-order flow pattern;
in step S4, a deformed wire frame model is obtained by the following method:
s41, dividing the driven subgraph into a plurality of flow pattern subgraphs according to the vehicle body structural member corresponding to each vertex in the driven subgraph and the flow pattern structure of the driven subgraph,
wherein the driven sub-graph is the other regions except the deformation region and the fixed region in the wire-frame model,
the flow pattern structure comprises a beam component subgraph as a first-order flow pattern and a plate component subgraph as a second-order flow pattern;
s42, calculating the deformation of each flow pattern subgraph forming the driven subgraph by a grid deformation method of Laplace coordinates,
wherein L is k Laplacian of order k flow pattern, δ = L k v is Laplace coordinate of each vertex v in the k-order flow pattern subgraph, and (i, j) represents the vertex v i And v j The set C is a vertex set shared by the slave subgraphs, the deformed subgraphs and the fixed subgraphs;
s43, assembling the deformed deformation subgraph, the driven subgraph and the fixed subgraph according to the shared vertex to obtain a deformed wire frame model;
s5, the deformation method of the three-dimensional model of the vehicle body structure comprises the following steps: s51, all vertexes { v ] in the wire-frame model before deformation, namely the wire-frame model in the step S3 i And (5) as a base point of the radial basis function deformation method, calculating deformation vectors of vertexes of the wire frame model before and after deformation:
d i ＝v′ i -v i ；
s52, calculating a deformation vector of any space point x by the following formula:
wherein, | x-v i L is from space point x to RBF base point v i Has a Euclidean distance of phi as a radial basis function, w i For base point v of RBF i The weight coefficients of the radial basis functions,
calculating the weight coefficient:
let x = v j D is obtained j ＝∑ i w i φ(|v j -v i |)＝∑ i w i φ ji
Wherein v is j Is a certain RBF base point, therefore, the weight coefficient w at each RBF base point can be obtained by the above formula i ；
And S53, substituting the grid vertex of the three-dimensional model into the deformation vector calculation formula in S52, calculating the deformation vector of the three-dimensional model vertex, and adding the deformation vector to the grid vertex to obtain the deformation result of the three-dimensional model.
2. The wire-frame representation and deformation method of a three-dimensional model of a vehicle body structure according to claim 1, wherein in step S1, a sub-graph model of a beam member is extracted in an automatic or manual manner, wherein the centerline of the extracted beam member satisfies the following relationship:
each beam member has a center line corresponding to the beam member, and the center line should penetrate through the beam member and pass through the center point of each cross section of the member;
the connecting positions of the beam members are composed of intersection points of a plurality of central lines corresponding to the beam members;
and adopting a broken line segment to represent the central line, and obtaining a group of vertex sets and straight edge sets connecting the vertices.
3. A wire frame representation and deformation method of a three-dimensional model of a vehicle body structure according to claim 2, wherein in steps S2, S3, the wire frame model is constructed by:
s21, establishing a connection relation between a subgraph of the beam member and an inner vertex of a subgraph of the plate member adjacent to the subgraph according to the adjacent relation of the beam and the plate member, and assembling the subgraph of the beam member and the subgraph of the plate member adjacent to the subgraph;
s22, assembling all the sub-graphs to obtain an initial graph model;
s31, respectively classifying vertexes in the initial graph model, wherein intersection points of three or more members are secondary vertexes, vertexes forming the convex hull of the initial wire frame model are primary vertexes, and other vertexes are zero-order vertexes;
s32, setting a length threshold value, meanwhile, ensuring that any straight edge contains at most one secondary vertex, and simplifying an initial graph model by the following method:
s321, if the length of a straight edge is greater than the threshold value, no operation is performed;
if the length of a certain straight edge is not greater than the threshold value, the following judgment is carried out:
when the two vertexes connected by the straight edge have the same grade, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the average value of the two vertexes connected by the straight edge,
when the two connected vertexes of the straight edge are different in grade, deleting the straight edge, introducing a new vertex and changing the connection relation of the wire frame model, wherein the coordinate position of the introduced new vertex is the same as the position of a vertex with a higher grade in the straight edge;
s322, connecting adjacent vertexes of the two vertexes of the straight edge with the introduced new vertex;
and S323, repeating the steps S321 and S322 until the length of the straight edge is smaller than the threshold value, and obtaining a simplified initial graph model, namely a wire frame model.
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| CN111964599A (en) * | 2020-04-26 | 2020-11-20 | 杭州同睿工程科技有限公司 | Highway high slope surface deformation monitoring and analyzing method based on oblique photogrammetry technology |
Citations (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008045392A2 (en) * | 2006-10-06 | 2008-04-17 | Savoy Mark A | Method and apparatus for assembling exterior automotive vehicle body components onto an automotive vehicle body |
| CN102222361A (en) * | 2010-04-06 | 2011-10-19 | 清华大学 | Method and system for capturing and reconstructing 3D model |
| CN102306396A (en) * | 2011-09-15 | 2012-01-04 | 山东大学 | Three-dimensional entity model surface finite element mesh automatic generation method |
| CN103049932A (en) * | 2012-12-20 | 2013-04-17 | 北京农业信息技术研究中心 | Radial basis function-based plant three-dimensional configuration virtual modeling method |
| EP2585975A1 (en) * | 2010-06-28 | 2013-05-01 | Precitec KG | A method for classifying a multitude of images recorded by a camera observing a processing area and laser material processing head using the same |
| CN103303367A (en) * | 2013-06-21 | 2013-09-18 | 电子科技大学 | Vehicle body stability control method for four-wheel drive electric vehicle |
| CN103521410A (en) * | 2013-10-14 | 2014-01-22 | 大连理工大学 | Method for automatically spray painting three-dimensional patterns on vehicle body surface |
| CN104133923A (en) * | 2013-05-31 | 2014-11-05 | 郑州宇通客车股份有限公司 | High-speed modification design method of vehicle body |
| CN104376179A (en) * | 2014-11-24 | 2015-02-25 | 大连理工大学 | Fast vehicle modeling rendering based on database |
| CN104392042A (en) * | 2014-11-24 | 2015-03-04 | 大连理工大学 | Fast 3D automobile body modeling method based on model database |
| CN105173921A (en) * | 2015-08-17 | 2015-12-23 | 宝鸡南车时代工程机械有限公司 | Simple contact net constant-tension wire barrow |
| CN105243243A (en) * | 2015-11-16 | 2016-01-13 | 武汉理工大学 | Car body aerodynamic modeling optimization method based on free deformation technology |
| EP1861679B1 (en) * | 2005-03-09 | 2016-03-02 | Commissariat à l'Énergie Atomique et aux Énergies Alternatives | Method and device for acquiring a geometric form |
| CN105966394A (en) * | 2015-03-11 | 2016-09-28 | 丰田自动车株式会社 | Vehicle body state quantity estimating device |
| CN106021701A (en) * | 2016-05-17 | 2016-10-12 | 吉林大学 | Car body beam frame collision modeling and analysis method considering characteristics of plastic hinge |
| CN106649992A (en) * | 2016-11-17 | 2017-05-10 | 复旦大学 | Ship and wake mesh model merging and optimization method |
| CN106971424A (en) * | 2017-03-13 | 2017-07-21 | 华侨大学 | A kind of shoe tree shoe last variation based on mesh deformation technique |
| CN106991722A (en) * | 2017-03-01 | 2017-07-28 | 浙江大学 | It is a kind of that the geometric mesh model deformation method of convex closure is influenceed based on oblique ellipsoid domain |
| CN107065567A (en) * | 2017-05-22 | 2017-08-18 | 江南大学 | A kind of automatic stopping control system that control is constrained based on adaptive neural network |
| CN107464285A (en) * | 2017-06-26 | 2017-12-12 | 北京长城华冠汽车科技股份有限公司 | The Meshing Method and device of a kind of threedimensional model |
| CN107491616A (en) * | 2017-08-24 | 2017-12-19 | 北京航空航天大学 | A kind of structure finite element parametric modeling method suitable for grid configuration rudder face |
| CN107609282A (en) * | 2017-09-18 | 2018-01-19 | 广州汽车集团股份有限公司 | A kind of conceptual design method of body shell |
| CN107832527A (en) * | 2017-11-09 | 2018-03-23 | 广州汽车集团股份有限公司 | A kind of vehicle body equivalent simplified model method for building up and system |
| CN108090963A (en) * | 2017-12-25 | 2018-05-29 | 大连理工大学 | A kind of numerical computation method of fibre reinforced composites thermal residual strain at low temperature |
| CN108230452A (en) * | 2017-12-18 | 2018-06-29 | 华侨大学 | A kind of model filling-up hole method based on textures synthesis |
-
2018
- 2018-07-11 CN CN201810754531.8A patent/CN109086492B/en active Active
Patent Citations (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1861679B1 (en) * | 2005-03-09 | 2016-03-02 | Commissariat à l'Énergie Atomique et aux Énergies Alternatives | Method and device for acquiring a geometric form |
| WO2008045392A2 (en) * | 2006-10-06 | 2008-04-17 | Savoy Mark A | Method and apparatus for assembling exterior automotive vehicle body components onto an automotive vehicle body |
| CN102222361A (en) * | 2010-04-06 | 2011-10-19 | 清华大学 | Method and system for capturing and reconstructing 3D model |
| EP2585975A1 (en) * | 2010-06-28 | 2013-05-01 | Precitec KG | A method for classifying a multitude of images recorded by a camera observing a processing area and laser material processing head using the same |
| CN102306396A (en) * | 2011-09-15 | 2012-01-04 | 山东大学 | Three-dimensional entity model surface finite element mesh automatic generation method |
| CN103049932A (en) * | 2012-12-20 | 2013-04-17 | 北京农业信息技术研究中心 | Radial basis function-based plant three-dimensional configuration virtual modeling method |
| CN104133923A (en) * | 2013-05-31 | 2014-11-05 | 郑州宇通客车股份有限公司 | High-speed modification design method of vehicle body |
| CN103303367A (en) * | 2013-06-21 | 2013-09-18 | 电子科技大学 | Vehicle body stability control method for four-wheel drive electric vehicle |
| CN103521410A (en) * | 2013-10-14 | 2014-01-22 | 大连理工大学 | Method for automatically spray painting three-dimensional patterns on vehicle body surface |
| CN104392042A (en) * | 2014-11-24 | 2015-03-04 | 大连理工大学 | Fast 3D automobile body modeling method based on model database |
| CN104376179A (en) * | 2014-11-24 | 2015-02-25 | 大连理工大学 | Fast vehicle modeling rendering based on database |
| CN105966394A (en) * | 2015-03-11 | 2016-09-28 | 丰田自动车株式会社 | Vehicle body state quantity estimating device |
| CN105173921A (en) * | 2015-08-17 | 2015-12-23 | 宝鸡南车时代工程机械有限公司 | Simple contact net constant-tension wire barrow |
| CN105243243A (en) * | 2015-11-16 | 2016-01-13 | 武汉理工大学 | Car body aerodynamic modeling optimization method based on free deformation technology |
| CN106021701A (en) * | 2016-05-17 | 2016-10-12 | 吉林大学 | Car body beam frame collision modeling and analysis method considering characteristics of plastic hinge |
| CN106649992A (en) * | 2016-11-17 | 2017-05-10 | 复旦大学 | Ship and wake mesh model merging and optimization method |
| CN106991722A (en) * | 2017-03-01 | 2017-07-28 | 浙江大学 | It is a kind of that the geometric mesh model deformation method of convex closure is influenceed based on oblique ellipsoid domain |
| CN106971424A (en) * | 2017-03-13 | 2017-07-21 | 华侨大学 | A kind of shoe tree shoe last variation based on mesh deformation technique |
| CN107065567A (en) * | 2017-05-22 | 2017-08-18 | 江南大学 | A kind of automatic stopping control system that control is constrained based on adaptive neural network |
| CN107464285A (en) * | 2017-06-26 | 2017-12-12 | 北京长城华冠汽车科技股份有限公司 | The Meshing Method and device of a kind of threedimensional model |
| CN107491616A (en) * | 2017-08-24 | 2017-12-19 | 北京航空航天大学 | A kind of structure finite element parametric modeling method suitable for grid configuration rudder face |
| CN107609282A (en) * | 2017-09-18 | 2018-01-19 | 广州汽车集团股份有限公司 | A kind of conceptual design method of body shell |
| CN107832527A (en) * | 2017-11-09 | 2018-03-23 | 广州汽车集团股份有限公司 | A kind of vehicle body equivalent simplified model method for building up and system |
| CN108230452A (en) * | 2017-12-18 | 2018-06-29 | 华侨大学 | A kind of model filling-up hole method based on textures synthesis |
| CN108090963A (en) * | 2017-12-25 | 2018-05-29 | 大连理工大学 | A kind of numerical computation method of fibre reinforced composites thermal residual strain at low temperature |
Non-Patent Citations (5)
| Title |
|---|
| 一类大型薄壁杆件装配体有限元快速精确建模研究及其在车身结构分析的应用;顾金伟;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20170515;C035-140 * |
| 基于代理模型的车身吸能结构抗撞性优化;郝亮;《中国博士学位论文全文数据库 工程科技Ⅱ辑》;20130815;C035-55 * |
| 基于自由变形技术的伴随方法优化设计大曲率扩压通道;于广元;《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》;20150115;摘要、正文第一至六章节 * |
| 快速网格变形技术在车身开发流程中的应用;闫亮;《内燃机与配件》;20170530;24-26 * |
| 面向车身结构分析的骨架驱动模型变形方法;李宝军;《湖南大学学报(自然科学版)》;20140825;摘要、正文第1-4节 * |
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