Method, device and equipment for monitoring internal force of space grid based on three-dimensional reconstruction

Abstract

The present invention discloses a method, device and equipment for monitoring the internal force of a space grid based on three-dimensional reconstruction. The method includes obtaining a three-dimensional reconstruction model of a space grid in an initial state and a three-dimensional reconstruction model of a space grid in a current state, and obtaining a three-dimensional reconstruction model alignment model between the two based on a grid model alignment strategy, and the current deformation amount and the current grid overall stiffness matrix corresponding to each ball node, and determining stress analysis results, internal force analysis results and balance verification results. The embodiment of the present invention can obtain the three-dimensional reconstruction models corresponding to the space grid in the initial state and the current state respectively based on image acquisition and three-dimensional reconstruction, determine the current deformation amount of the ball node and the current grid overall stiffness matrix by combining the two three-dimensional reconstruction models, analyze and obtain stress analysis results, internal force analysis results and balance verification results, and there is no need to attach strain gauges at the ball nodes, which not only reduces the construction cost, but also improves the efficiency and accuracy of obtaining the relevant results of the internal force monitoring of the space grid.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a method, device and equipment for monitoring the internal force of a space grid based on three-dimensional reconstruction. Background Art

[0002] The space grid structure is a mesh space bar system structure composed of multiple bars through ball nodes according to a certain rule. It has been widely used in the construction process of stadiums, exhibition centers, cultural facilities, transportation hubs or industrial plants that require large spans and large spaces. When monitoring the internal force of the space grid structure, strain gauges are generally attached to the ball nodes. The above-mentioned method of attaching strain gauges not only has a large construction workload and high construction costs, but also has a huge amount of data after data collection from multiple strain gauges and then data processing, resulting in low calculation efficiency and low reliability of calculation results. Summary of the invention

[0003] The embodiments of the present invention provide a method, device and equipment for monitoring the internal force of a space grid structure based on three-dimensional reconstruction, aiming to solve the problem that in the prior art, when monitoring the internal force of a space grid structure, strain gauges are attached to the ball nodes, which not only has a large construction workload and high construction cost, but also the data acquisition and data processing of multiple strain gauges will result in a huge amount of data, resulting in low calculation efficiency and low reliability of calculation results.

[0004] In a first aspect, an embodiment of the present invention provides a method for monitoring internal forces of a space grid based on three-dimensional reconstruction, which comprises:

[0005] In response to the spatial grid internal force monitoring instruction, an initial state spatial grid three-dimensional reconstruction model is obtained; wherein the initial state spatial grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the spatial grid image collected when the spatial grid is initially spliced ​​and not placed in the actual installation position;

[0006] Obtaining a three-dimensional reconstruction model of the current state space grid; wherein the three-dimensional reconstruction model of the current state space grid is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position;

[0007] Acquire a three-dimensional reconstruction model alignment model between the current state space grid three-dimensional reconstruction model and the initial state space grid three-dimensional reconstruction model based on a preset grid model alignment strategy;

[0008] Determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model;

[0009] Acquire the current grid overall stiffness matrix corresponding to the three-dimensional reconstruction model of the current state space grid;

[0010] Based on the current grid overall stiffness matrix and the current deformation, the stress analysis results, internal force analysis results and balance verification results corresponding to the current state space grid three-dimensional reconstruction model are determined.

[0011] In a second aspect, an embodiment of the present invention further provides a spatial grid internal force monitoring device based on three-dimensional reconstruction, which includes:

[0012] An initial grid three-dimensional reconstruction model acquisition unit is used to respond to the spatial grid internal force monitoring instruction to acquire an initial state spatial grid three-dimensional reconstruction model; wherein the initial state spatial grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the spatial grid image collected when the spatial grid is initially spliced ​​and not placed in the actual installation position;

[0013] A current grid three-dimensional reconstruction model acquisition unit is used to acquire a current state space grid three-dimensional reconstruction model; wherein the current state space grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position;

[0014] A 3D reconstruction model alignment model acquisition unit, used for acquiring a 3D reconstruction model alignment model between the current state space grid 3D reconstruction model and the initial state space grid 3D reconstruction model based on a preset grid model alignment strategy;

[0015] A current deformation amount determination unit is used to determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation amount corresponding to the current state space grid three-dimensional reconstruction model;

[0016] A stiffness matrix acquisition unit, used to acquire the current grid overall stiffness matrix corresponding to the three-dimensional reconstruction model of the current state space grid;

[0017] The internal force monitoring unit is used to determine the stress analysis results, internal force analysis results and balance verification results corresponding to the three-dimensional reconstruction model of the current state space frame based on the current overall stiffness matrix of the frame and the current deformation.

[0018] In a third aspect, an embodiment of the present invention further provides a computer device, which includes a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the method described in the first aspect is implemented.

[0019] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer storage medium stores a computer program, wherein the computer program includes program instructions, and when the program instructions are executed by a processor, the method described in the first aspect above can be implemented.

[0020] The embodiment of the present invention provides a method, device and equipment for monitoring the internal force of a space grid based on 3D reconstruction. The method comprises: in response to a space grid internal force monitoring instruction, obtaining an initial state 3D reconstruction model of the space grid; wherein the initial state 3D reconstruction model of the space grid is obtained by performing 3D reconstruction on a space grid image collected when the space grid is initially spliced ​​and not placed in an actual installation position; obtaining a current state 3D reconstruction model of the space grid; wherein the current state 3D reconstruction model of the space grid is obtained by performing 3D reconstruction on a space grid image collected when the space grid is spliced ​​and placed in an actual installation position; obtaining the current state 3D reconstruction model of the space grid based on a preset grid model alignment strategy. The three-dimensional reconstruction model alignment model between the three-dimensional reconstruction model of the space grid and the three-dimensional reconstruction model of the initial state space grid; based on the three-dimensional reconstruction model alignment model, the displacement of each ball node in the three-dimensional reconstruction model of the current state space grid and the corresponding ball node in the three-dimensional reconstruction model of the initial state space grid is determined, and the current deformation corresponding to the three-dimensional reconstruction model of the space grid in the current state is determined; the overall stiffness matrix of the current grid corresponding to the three-dimensional reconstruction model of the space grid in the current state is obtained; based on the overall stiffness matrix of the current grid and the current deformation, the stress analysis result, the internal force analysis result and the balance verification result corresponding to the three-dimensional reconstruction model of the space grid in the current state are determined. The embodiment of the present invention can obtain the three-dimensional reconstruction models corresponding to the space grid in the initial state and the current state respectively based on image acquisition and three-dimensional reconstruction, and then determine the current deformation of the ball node and the overall stiffness matrix of the current grid by combining the two three-dimensional reconstruction models, and determine the stress analysis result, the internal force analysis result and the balance verification result obtained by analysis, without the need to attach strain gauges at the ball nodes, which not only reduces the construction cost, but also improves the efficiency and accuracy of obtaining the internal force monitoring related results of the space grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0022] Figure 1 A schematic diagram of an application scenario of a spatial grid internal force monitoring method based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0023] Figure 2 A schematic flow chart of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a sub-process of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0025] Figure 4A A schematic diagram of a model of a three-dimensional reconstruction model of a space grid in an initial state in a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0026] Figure 4B A schematic diagram of a model of a three-dimensional reconstruction model of a space grid in a current state in a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of a sub-process of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of a sub-process of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0029] Figure 7 A schematic diagram of a sub-process of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0030] Figure 8 A schematic block diagram of a spatial grid internal force monitoring device based on three-dimensional reconstruction provided by an embodiment of the present invention;

[0031] Fig. 9 A schematic block diagram of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0034] It should also be understood that the terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0035] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0036] Please also refer to Figure 1 and Figure 2 ,in Figure 1 Schematic diagram of a scene of a method for monitoring internal forces of a space grid based on three-dimensional reconstruction according to an embodiment of the present invention. Figure 2 FIG. 1 is a flow chart of a method for monitoring the internal force of a space grid based on three-dimensional reconstruction provided by an embodiment of the present invention. Figure 1 As shown, the spatial grid internal force monitoring method based on three-dimensional reconstruction provided in an embodiment of the present invention is applied to a server 10, and the server 10 is communicatively connected with an image acquisition device 20 and a user terminal.

[0037] like Figure 2 As shown, the method includes the following steps S110-S160.

[0038] S110, in response to the spatial grid internal force monitoring instruction, obtaining the initial state spatial grid three-dimensional reconstruction model.

[0039] The three-dimensional reconstruction model of the initial state space grid is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is initially spliced ​​and not placed in the actual installation position.

[0040] In this embodiment, taking the deployment of a space grid in any scenario such as a stadium, convention and exhibition center, cultural facility, transportation hub or industrial plant as an example, when the space grid is initially spliced ​​and not placed in the actual installation position, an image acquisition device such as an aerial photography device (such as a drone equipped with a camera) can be used to capture multiple frames of initial state images of the space grid that has been initially spliced ​​and not placed in the actual installation position to form an initial state image set of the space grid.

[0041] Afterwards, when obtaining the initial state space grid three-dimensional reconstruction model based on the initial state image set of the space grid, it is necessary to combine the preset three-dimensional reconstruction strategy, as follows:

[0042] 11) Extracting image feature points from each frame of the spatial grid initial state image in the spatial grid initial state image set according to a preset feature point extraction model (such as fast feature point extraction and description), and performing feature point matching processing on multiple image feature points to establish feature point correspondence between feature points of each image;

[0043] 12) The corresponding relationship of the feature points is combined with the camera parameters of the image acquisition device to determine the camera motion trajectory, and the multi-view geometric relationship of the initial state image of each frame of the spatial grid in the initial state image set is determined according to the camera motion trajectory; wherein the camera parameters of the image acquisition device at least include a basic matrix and an essential matrix;

[0044] 13) According to the feature point correspondence relationship between each image feature point and the multi-view geometric relationship, the image feature point correspondence of each frame space grid initial state image is converted into an initial point cloud and then subjected to Poisson dense reconstruction processing to obtain an initial target point cloud, and the initial target point cloud is used as the initial state space grid three-dimensional reconstruction model.

[0045] The three-dimensional reconstruction model of the initial state space grid is obtained through the above process. The spatial position of each rod unit in the space grid in the three-dimensional space, the three-dimensional spatial coordinates of the sphere center corresponding to the spherical nodes at both ends of each rod unit in the three-dimensional space, and the radius of the spherical nodes are also known.

[0046] S120, obtaining a three-dimensional reconstruction model of the current state space grid.

[0047] The three-dimensional reconstruction model of the current state space grid is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position.

[0048] In this embodiment, when the spatial grid is completed and placed in the actual installation position, the image acquisition device is still used to capture multiple frames of current state images of the spatial grid that has completed splicing and placed in the actual installation position to form a current state image set of the spatial grid.

[0049] Afterwards, in the process of constructing the current state space grid three-dimensional reconstruction model according to the current state image set of the space grid, the process of constructing the initial state space grid three-dimensional reconstruction model according to the initial state image set of the space grid can also be referred to, and no further description is given here. When the space grid is completed and placed in the actual installation position, the difference from the initial completion of the splicing and not placed in the actual installation position is that the rod unit and / or ball node in the space grid will be displaced, which requires subsequent comparison analysis to determine.

[0050] Moreover, in order to have a clearer understanding of the technical solution of the present application, it can be assumed that the space grid corresponding to the initial state space grid three-dimensional reconstruction model is placed in the initial state, and the entire space grid is translated in the same direction as a whole to obtain the most initial current state space grid three-dimensional reconstruction model. However, after the space grid is actually subjected to force, the rod units and / or ball nodes will be displaced, thereby obtaining the current state space grid three-dimensional reconstruction model.

[0051] S130, obtaining a three-dimensional reconstruction model alignment model between the current state space grid three-dimensional reconstruction model and the initial state space grid three-dimensional reconstruction model based on a preset grid model alignment strategy.

[0052] In this embodiment, since the current state spatial grid 3D reconstruction model corresponds to the state of the spatial grid after the splicing is completed and placed in the actual installation position, and the initial state spatial grid 3D reconstruction model corresponds to the state of the spatial grid after the initial splicing is completed and not placed in the actual installation position, the alignment result between the current state spatial grid 3D reconstruction model and the initial state spatial grid 3D reconstruction model can be obtained when the initial state spatial grid 3D reconstruction model is used as the reference model. After the two are aligned, the displacement of each rod unit and ball node in the spatial grid can be further determined.

[0053] In one embodiment, as a first embodiment of the grid model alignment strategy, Figure 3 As shown, step S130 includes:

[0054] S131A, based on the vertex screening sub-strategy in the grid model alignment strategy, select a vertex ball node from the initial state space grid 3D reconstruction model and use it as a reference origin;

[0055] S132A, obtaining at least two reference rod elements having one end connected to a vertex ball node corresponding to the reference origin based on the rod screening sub-strategy in the grid model alignment strategy;

[0056] S133A. Align the current state vertex ball nodes corresponding to the reference origin in the current state space grid three-dimensional reconstruction model, and align the current state rod units corresponding to at least two reference rod units in the current state space grid three-dimensional reconstruction model to obtain the three-dimensional reconstruction model alignment model.

[0057] In this embodiment, in order to more clearly understand the alignment process of the current state space grid 3D reconstruction model and the initial state space grid 3D reconstruction model, reference may be made to the following. Figure 4A The initial state space grid 3D reconstruction model similar to the triangular pyramid shape Figure 4BThe alignment process between the current state space grid 3D reconstruction model is also similar to the triangular pyramid. First, based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node can be selected from the initial state space grid 3D reconstruction model and used as the reference origin. For example, Figure 4A The vertex ball node A1 in the three-dimensional reconstruction model of the space grid is used as the reference origin (more specifically, the center of the vertex ball node A1 is used as the reference origin). Then, the rod unit connecting the vertex ball node A1 and the vertex ball node A2, and the rod unit connecting the vertex ball node A1 and the vertex ball node A3 are obtained based on the rod screening sub-strategy in the grid model alignment strategy and used as reference rod units. Finally, the vertex ball node B1 in the current state space grid three-dimensional reconstruction model is aligned with the vertex ball node A1 in the initial state space grid three-dimensional reconstruction model, and the rod unit between the vertex ball node B1 and the vertex ball node B2 is parallel to the reference rod unit between the vertex ball node A1 and the vertex ball node A2, and the rod unit between the vertex ball node B1 and the vertex ball node B3 is parallel to the reference rod unit between the vertex ball node A1 and the vertex ball node A3. After the above alignment process, the three-dimensional reconstruction model alignment model that simultaneously includes the initial state space grid three-dimensional reconstruction model can be obtained. Moreover, in the above process, the initial state space grid three-dimensional reconstruction model may not be moved, but it may be used as a reference model to move the current state space grid three-dimensional reconstruction model accordingly.

[0058] In one embodiment, as a second embodiment of the grid model alignment strategy, Figure 5 As shown, step S130 includes:

[0059] S131B, based on the vertex screening sub-strategy in the grid model alignment strategy, select a vertex ball node from the initial state space grid 3D reconstruction model and use it as a reference origin;

[0060] S132B, obtaining the current state vertex ball node corresponding to the reference origin in the current state space grid three-dimensional reconstruction model, and aligning it with the reference origin;

[0061] S133B, obtain the remaining vertex ball node set after removing the current state vertex ball node in the current state space grid three-dimensional reconstruction model, and obtain the corresponding translated current state space grid three-dimensional reconstruction model under the state that satisfies the sum of the squares of the distances between each vertex ball node in the remaining vertex ball node set and the corresponding vertex ball nodes in the initial state space grid three-dimensional reconstruction model is minimum, and form the three-dimensional reconstruction model alignment model with the initial state space grid three-dimensional reconstruction model.

[0062] In this embodiment, reference can still be made to Figure 4A and Figure 4B In the second embodiment of the grid model alignment strategy, it is only necessary to align the vertex ball node B1 in the current state space grid 3D reconstruction model with the vertex ball node A1 in the initial state space grid 3D reconstruction model. After that, there is no need to align the rod elements. Instead, a method is sought such that (the sphere center coordinates of the vertex ball node B2 - the sphere center coordinates of the vertex ball node A2) 2 + (the coordinates of the center of the vertex ball node B3 - the coordinates of the center of the vertex ball node A3) 2 + (the coordinates of the center of the vertex ball node B4 - the coordinates of the center of the vertex ball node A4) 2 The corresponding translated current state space grid 3D reconstruction model under the minimum state forms the 3D reconstruction model alignment model with the initial state space grid 3D reconstruction model. Similarly, in the above process, the initial state space grid 3D reconstruction model may not be moved, but the current state space grid 3D reconstruction model may be moved accordingly using it as a reference model, and the sum of the squares of the distances between each vertex ball node in the remaining vertex ball node set and the corresponding vertex ball node in the initial state space grid 3D reconstruction model is in the minimum state.

[0063] S140. Determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model.

[0064] In this embodiment, after obtaining the three-dimensional reconstruction model alignment model, the displacement of each ball node in the initial state space grid three-dimensional reconstruction model in the three-dimensional reconstruction model alignment model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model can be combined, and the displacement of the rod unit between each two adjacent ball nodes can be further derived, so as to comprehensively determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model.

[0065] In one embodiment, step S140 includes:

[0066] Based on the three-dimensional reconstruction model alignment model and the reference space coordinate system corresponding to the initial state space grid three-dimensional reconstruction model, the displacement of each ball node in the current state space grid three-dimensional reconstruction model relative to the corresponding ball node in the initial state space grid three-dimensional reconstruction model is determined, and the current deformation is composed of the displacement of each ball node in the current state space grid three-dimensional reconstruction model.

[0067] In this embodiment, in order to more quickly determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model relative to the corresponding ball node in the initial state space grid three-dimensional reconstruction model, a vertex ball node can still be selected in the initial state space grid three-dimensional reconstruction model and used as the reference origin to construct a reference space coordinate system, and the space coordinate adjustment vector can be determined based on the difference between the space coordinates of the vertex ball node (such as considering the coordinates of the center of the ball node as the coordinates of the ball node) in the physical world and the coordinates (0,0,0) corresponding to the reference origin, and the space coordinate adjustment vector is used as the space coordinate adjustment vector of other rod units and ball nodes in the initial state space grid three-dimensional reconstruction model. After constructing the reference space coordinate system based on the reference origin and the space coordinate adjustment vector, the coordinates of each ball node in the reference space coordinate system in the current state space grid three-dimensional reconstruction model can be quickly obtained, and then the coordinates of each ball node in the current state space grid three-dimensional reconstruction model are subtracted from the coordinates of the corresponding ball node in the initial state space grid three-dimensional reconstruction model, so as to quickly determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and form the current deformation.

[0068] S150, obtaining the current grid overall stiffness matrix corresponding to the three-dimensional reconstruction model of the current state space grid.

[0069] In this embodiment, after determining the current deformation of the current state space grid 3D reconstruction model, the current grid overall stiffness matrix corresponding to the current state space grid 3D reconstruction model can be further obtained. In specific implementation, the unit stiffness matrix corresponding to each rod unit in the current state space grid 3D reconstruction model can be first obtained, and then the current grid overall stiffness matrix can be formed.

[0070] In one embodiment, if Figure 6 As shown, step S150 includes:

[0071] S151, for each rod element in the three-dimensional reconstruction model of the current state space grid, determine the unit stiffness matrix of the rod element in the local coordinate system according to the ball node numbers at both ends of the rod element;

[0072] S152, determining a transformed unit stiffness matrix of the bar unit in the reference space coordinate system based on a coordinate transformation matrix between the local coordinate system and the reference space coordinate system corresponding to the three-dimensional reconstruction model of the initial state space grid;

[0073] S153. According to the order corresponding to the ball node numbers at both ends of each rod unit in the three-dimensional reconstruction model of the current state space grid, the converted unit stiffness matrix of each rod unit in the three-dimensional reconstruction model of the current state space grid is spliced ​​to form the overall stiffness matrix of the current grid.

[0074] In this embodiment, for each rod unit in the current state space truss three-dimensional reconstruction model, according to the ball node numbering at both ends of the rod unit, for example, the ball nodes at both ends of a rod unit are numbered m and n respectively (where m and n are both positive integers), and the current state space truss three-dimensional reconstruction model includes a total of NT1 ball nodes and NT2 rod units (NT1 and NT2 are both positive integers), assuming that the length of the rod unit between two ball nodes with node numbers m and n is L, the cross-sectional area is A, and the elastic modulus is E, then the unit stiffness matrix of the above-mentioned rod unit in the local coordinate system can be regarded as a 6×6 unit stiffness matrix (the process of obtaining the unit stiffness matrix needs to be combined with the deformation formula of the axial tension and compression rod ΔL=FL / EA, where ΔL is the axial deformation of the rod unit, F is the axial force, and the unit stiffness matrix of the rod unit in the local coordinate system can be determined based on EA / L). After that, the direction cosines of the rod unit in the local coordinate system and the reference space coordinate system corresponding to the initial state space grid three-dimensional reconstruction model in the x, y, and z axes are obtained, and a coordinate transformation matrix is ​​formed. Then, the unit stiffness matrix of the rod unit and the coordinate transformation matrix are processed by coordinate transformation, such as the coordinate transformation processing of the transpose matrix of the coordinate transformation matrix × the unit stiffness matrix of the rod unit × the coordinate transformation matrix, and the transformed unit stiffness matrix of the rod unit in the reference space coordinate system can be obtained. Finally, the numbers of the ball nodes at both ends of each rod unit in the overall structure corresponding to the three-dimensional reconstruction model of the current state space grid are placed in the corresponding positions of the overall stiffness matrix, and the overall stiffness matrix of the current grid can be obtained.

[0075] S160. Based on the current grid overall stiffness matrix and the current deformation, determine the stress analysis results, internal force analysis results and balance verification results corresponding to the current state space grid three-dimensional reconstruction model.

[0076] In this embodiment, after determining the current overall stiffness matrix of the spatial grid and the current deformation, stress analysis, internal force analysis and balance verification can be performed to obtain corresponding stress analysis results, internal force analysis results and balance verification results.

[0077] In one embodiment, if Figure 7 As shown, step S160 includes:

[0078] S161, obtaining the node displacement corresponding to the current deformation of each rod unit in the three-dimensional reconstruction model of the current state space grid, and obtaining the rod unit length of each rod unit, based on the displacement component of the node displacement of each rod unit in the axial direction of the rod unit multiplied by the elastic modulus of the rod unit divided by the rod unit length, to obtain the stress value of each rod unit, and compose the stress analysis result;

[0079] S162, obtaining the stress value of each bar unit in the three-dimensional reconstruction model of the current state space grid and multiplying it by the cross-sectional area of ​​the corresponding bar unit to obtain the internal force value of each bar unit, and forming the internal force analysis result;

[0080] S163. Based on the current overall stiffness matrix of the truss, the node displacement corresponding to the current deformation and the preset node force determination strategy, determine the node force corresponding to each ball node in the three-dimensional reconstruction model of the current state space truss, and compare the node force corresponding to each ball node with the preset node force threshold to obtain the balance verification result.

[0081] In this embodiment, since the node displacement corresponding to each bar unit in the current state space grid three-dimensional reconstruction model in the current deformation and the overall stiffness matrix of the current grid have been determined before, the stress value and internal force value of each bar unit can be calculated respectively in combination with the bar unit length and the elastic modulus of each bar unit. In addition, the node force corresponding to each ball node in the current state space grid three-dimensional reconstruction model is determined in combination with the node force determination strategy (such as the static equilibrium equation method), and the node force corresponding to each ball node is compared with the preset node force threshold to obtain the balance verification result. Specifically, if it is determined that the node force corresponding to each ball node is less than the preset node force threshold, the balance verification pass result is used as the balance verification result; if it is determined that the node force corresponding to a ball node is greater than the node force threshold, the node number of the corresponding ball node in the current state space grid three-dimensional reconstruction model is obtained, and the node number and the balance verification failure result are used as the balance verification result.

[0082] It can be seen that the embodiment of the method can obtain the three-dimensional reconstruction models corresponding to the initial state and the current state of the space truss respectively based on image acquisition and three-dimensional reconstruction, and then determine the current deformation of the ball node and the current overall stiffness matrix of the truss by combining the two three-dimensional reconstruction models, and determine the stress analysis results, internal force analysis results and balance verification results obtained by analysis. There is no need to attach strain gauges at the ball nodes, which not only reduces the construction cost, but also improves the efficiency and accuracy of obtaining the relevant results of the internal force monitoring of the space truss.

[0083] Figure 8is a schematic block diagram of a spatial grid internal force monitoring device based on three-dimensional reconstruction provided by an embodiment of the present invention. Figure 8 As shown, corresponding to the above-mentioned space grid internal force monitoring method based on three-dimensional reconstruction, the present invention also provides a space grid internal force monitoring device 100 based on three-dimensional reconstruction. Figure 8 As shown, the spatial truss internal force monitoring device 100 based on three-dimensional reconstruction includes an initial truss three-dimensional reconstruction model acquisition unit 110, a current truss three-dimensional reconstruction model acquisition unit 120, a three-dimensional reconstruction model alignment model acquisition unit 130, a current deformation determination unit 140, a stiffness matrix acquisition unit 150 and an internal force monitoring unit 160.

[0084] The initial grid three-dimensional reconstruction model acquisition unit 110 is used to obtain the initial state space grid three-dimensional reconstruction model in response to the space grid internal force monitoring instruction.

[0085] The three-dimensional reconstruction model of the initial state space grid is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is initially spliced ​​and not placed in the actual installation position.

[0086] In this embodiment, taking the deployment of a space grid in any scenario such as a stadium, convention and exhibition center, cultural facility, transportation hub or industrial plant as an example, when the space grid is initially spliced ​​and not placed in the actual installation position, an image acquisition device such as an aerial photography device (such as a drone equipped with a camera) can be used to capture multiple frames of initial state images of the space grid that has been initially spliced ​​and not placed in the actual installation position to form an initial state image set of the space grid.

[0087] Afterwards, when obtaining the initial state space grid three-dimensional reconstruction model based on the initial state image set of the space grid, it is necessary to combine the preset three-dimensional reconstruction strategy. Through the initial state space grid three-dimensional reconstruction model obtained by the above process, the spatial position of each rod unit in the space grid in three-dimensional space, the three-dimensional spatial coordinates of the sphere center corresponding to the spherical nodes at both ends of each rod unit in three-dimensional space, and the radius of the spherical nodes are also known.

[0088] The current grid 3D reconstruction model acquisition unit 120 is used to acquire the current state space grid 3D reconstruction model.

[0089] The three-dimensional reconstruction model of the current state space grid is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position.

[0090] In this embodiment, when the spatial grid is completed and placed in the actual installation position, the image acquisition device is still used to capture multiple frames of current state images of the spatial grid that has completed splicing and placed in the actual installation position to form a current state image set of the spatial grid.

[0091] Afterwards, in the process of constructing the current state space grid three-dimensional reconstruction model according to the current state image set of the space grid, the process of constructing the initial state space grid three-dimensional reconstruction model according to the initial state image set of the space grid can also be referred to, and no further description is given here. When the space grid is completed and placed in the actual installation position, the difference from the initial completion of the splicing and not placed in the actual installation position is that the rod unit and / or ball node in the space grid will be displaced, which requires subsequent comparison analysis to determine.

[0092] Moreover, in order to have a clearer understanding of the technical solution of the present application, it can be assumed that the space grid corresponding to the initial state space grid three-dimensional reconstruction model is placed in the initial state, and the entire space grid is translated in the same direction as a whole to obtain the most initial current state space grid three-dimensional reconstruction model. However, after the space grid is actually subjected to force, the rod units and / or ball nodes will be displaced, thereby obtaining the current state space grid three-dimensional reconstruction model.

[0093] The 3D reconstruction model alignment model acquisition unit 130 is used to acquire a 3D reconstruction model alignment model between the current state space grid 3D reconstruction model and the initial state space grid 3D reconstruction model based on a preset grid model alignment strategy.

[0094] In this embodiment, since the current state spatial grid 3D reconstruction model corresponds to the state of the spatial grid after the splicing is completed and placed in the actual installation position, and the initial state spatial grid 3D reconstruction model corresponds to the state of the spatial grid after the initial splicing is completed and not placed in the actual installation position, the alignment result between the current state spatial grid 3D reconstruction model and the initial state spatial grid 3D reconstruction model can be obtained when the initial state spatial grid 3D reconstruction model is used as the reference model. After the two are aligned, the displacement of each rod unit and ball node in the spatial grid can be further determined.

[0095] In one embodiment, as a first embodiment of the grid model alignment strategy, the 3D reconstruction model alignment model acquisition unit 130 is specifically used to:

[0096] Based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node is selected from the initial state space grid three-dimensional reconstruction model and used as a reference origin;

[0097] Acquire at least two reference rod elements having one end connected to a vertex ball node corresponding to the reference origin based on the rod screening sub-strategy in the grid model alignment strategy;

[0098] The current state vertex ball nodes corresponding to the reference origin in the current state space grid three-dimensional reconstruction model are aligned, and the current state rod units corresponding to at least two reference rod units in the current state space grid three-dimensional reconstruction model are aligned to obtain the three-dimensional reconstruction model alignment model.

[0099] In this embodiment, in order to more clearly understand the alignment process of the current state space grid 3D reconstruction model and the initial state space grid 3D reconstruction model, reference may be made to the following. Figure 4A The initial state space grid 3D reconstruction model similar to the triangular pyramid shape Figure 4B The alignment process between the current state space grid 3D reconstruction model is also similar to the triangular pyramid. First, based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node can be selected from the initial state space grid 3D reconstruction model and used as the reference origin. For example, Figure 4A The vertex ball node A1 in the three-dimensional reconstruction model of the space grid is used as the reference origin (more specifically, the center of the vertex ball node A1 is used as the reference origin). Then, the rod unit connecting the vertex ball node A1 and the vertex ball node A2, and the rod unit connecting the vertex ball node A1 and the vertex ball node A3 are obtained based on the rod screening sub-strategy in the grid model alignment strategy and used as reference rod units. Finally, the vertex ball node B1 in the current state space grid three-dimensional reconstruction model is aligned with the vertex ball node A1 in the initial state space grid three-dimensional reconstruction model, and the rod unit between the vertex ball node B1 and the vertex ball node B2 is parallel to the reference rod unit between the vertex ball node A1 and the vertex ball node A2, and the rod unit between the vertex ball node B1 and the vertex ball node B3 is parallel to the reference rod unit between the vertex ball node A1 and the vertex ball node A3. After the above alignment process, the three-dimensional reconstruction model alignment model that simultaneously includes the initial state space grid three-dimensional reconstruction model can be obtained. Moreover, in the above process, the initial state space grid three-dimensional reconstruction model may not be moved, but it may be used as a reference model to move the current state space grid three-dimensional reconstruction model accordingly.

[0100] In one embodiment, as a second embodiment of the grid model alignment strategy, the 3D reconstruction model alignment model acquisition unit 130 is specifically used to:

[0101] Based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node is selected from the initial state space grid three-dimensional reconstruction model and used as a reference origin;

[0102] Acquire the current state vertex ball node corresponding to the reference origin in the current state space grid three-dimensional reconstruction model, and align it with the reference origin;

[0103] Obtain the remaining vertex ball node set after removing the current state vertex ball node in the current state space grid three-dimensional reconstruction model, and obtain the corresponding translated current state space grid three-dimensional reconstruction model under the state that satisfies the sum of the squares of the distances between each vertex ball node in the remaining vertex ball node set and the corresponding vertex ball nodes in the initial state space grid three-dimensional reconstruction model is minimum, and form the three-dimensional reconstruction model alignment model with the initial state space grid three-dimensional reconstruction model.

[0104] In this embodiment, reference can still be made to Figure 4A and Figure 4B In the second embodiment of the grid model alignment strategy, it is only necessary to align the vertex ball node B1 in the current state space grid 3D reconstruction model with the vertex ball node A1 in the initial state space grid 3D reconstruction model. After that, there is no need to align the rod elements. Instead, a method is sought such that (the sphere center coordinates of the vertex ball node B2 - the sphere center coordinates of the vertex ball node A2) 2 + (the coordinates of the center of the vertex ball node B3 - the coordinates of the center of the vertex ball node A3) 2 + (the coordinates of the center of the vertex ball node B4 - the coordinates of the center of the vertex ball node A4) 2 The corresponding translated current state space grid 3D reconstruction model under the minimum state forms the 3D reconstruction model alignment model with the initial state space grid 3D reconstruction model. Similarly, in the above process, the initial state space grid 3D reconstruction model may not be moved, but the current state space grid 3D reconstruction model may be moved accordingly using it as a reference model, and the sum of the squares of the distances between each vertex ball node in the remaining vertex ball node set and the corresponding vertex ball node in the initial state space grid 3D reconstruction model is in the minimum state.

[0105] The current deformation determination unit 140 is used to determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model.

[0106] In this embodiment, after obtaining the three-dimensional reconstruction model alignment model, the displacement of each ball node in the initial state space grid three-dimensional reconstruction model in the three-dimensional reconstruction model alignment model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model can be combined, and the displacement of the rod unit between each two adjacent ball nodes can be further derived, so as to comprehensively determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model.

[0107] In one embodiment, the current deformation amount determining unit 140 is specifically used to:

[0108] Based on the three-dimensional reconstruction model alignment model and the reference space coordinate system corresponding to the initial state space grid three-dimensional reconstruction model, the displacement of each ball node in the current state space grid three-dimensional reconstruction model relative to the corresponding ball node in the initial state space grid three-dimensional reconstruction model is determined, and the current deformation is composed of the displacement of each ball node in the current state space grid three-dimensional reconstruction model.

[0109] In this embodiment, in order to more quickly determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model relative to the corresponding ball node in the initial state space grid three-dimensional reconstruction model, a vertex ball node can still be selected in the initial state space grid three-dimensional reconstruction model and used as the reference origin to construct a reference space coordinate system, and the space coordinate adjustment vector can be determined based on the difference between the space coordinates of the vertex ball node (such as considering the coordinates of the center of the ball node as the coordinates of the ball node) in the physical world and the coordinates (0,0,0) corresponding to the reference origin, and the space coordinate adjustment vector is used as the space coordinate adjustment vector of other rod units and ball nodes in the initial state space grid three-dimensional reconstruction model. After constructing the reference space coordinate system based on the reference origin and the space coordinate adjustment vector, the coordinates of each ball node in the reference space coordinate system in the current state space grid three-dimensional reconstruction model can be quickly obtained, and then the coordinates of each ball node in the current state space grid three-dimensional reconstruction model are subtracted from the coordinates of the corresponding ball node in the initial state space grid three-dimensional reconstruction model, so as to quickly determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and form the current deformation.

[0110] The stiffness matrix acquisition unit 150 is used to acquire the current grid overall stiffness matrix corresponding to the current state space grid three-dimensional reconstruction model.

[0111] In this embodiment, after determining the current deformation of the current state space grid 3D reconstruction model, the current grid overall stiffness matrix corresponding to the current state space grid 3D reconstruction model can be further obtained. In specific implementation, the unit stiffness matrix corresponding to each rod unit in the current state space grid 3D reconstruction model can be first obtained, and then the current grid overall stiffness matrix can be formed.

[0112] In one embodiment, the stiffness matrix acquisition unit 150 is specifically used for:

[0113] For each rod element in the three-dimensional reconstruction model of the current state space grid, determine the element stiffness matrix of the rod element in the local coordinate system according to the ball node numbers at both ends of the rod element;

[0114] Determine the transformed unit stiffness matrix of the bar element in the reference space coordinate system based on the coordinate transformation matrix between the local coordinate system and the reference space coordinate system corresponding to the three-dimensional reconstruction model of the initial state space grid;

[0115] According to the corresponding order of the ball node numbers at both ends of each rod unit in the current state space grid three-dimensional reconstruction model, the converted unit stiffness matrix of each rod unit in the current state space grid three-dimensional reconstruction model is spliced ​​to form the current grid overall stiffness matrix.

[0116] In this embodiment, for each rod unit in the current state space truss three-dimensional reconstruction model, according to the ball node numbering at both ends of the rod unit, for example, the ball nodes at both ends of a rod unit are numbered m and n respectively (where m and n are both positive integers), and the current state space truss three-dimensional reconstruction model includes a total of NT1 ball nodes and NT2 rod units (NT1 and NT2 are both positive integers), assuming that the length of the rod unit between two ball nodes with node numbers m and n is L, the cross-sectional area is A, and the elastic modulus is E, then the unit stiffness matrix of the above-mentioned rod unit in the local coordinate system can be regarded as a 6×6 unit stiffness matrix (the process of obtaining the unit stiffness matrix needs to be combined with the deformation formula of the axial tension and compression rod ΔL=FL / EA, where ΔL is the axial deformation of the rod unit, F is the axial force, and the unit stiffness matrix of the rod unit in the local coordinate system can be determined based on EA / L). After that, the direction cosines of the rod unit in the local coordinate system and the reference space coordinate system corresponding to the initial state space grid three-dimensional reconstruction model in the x, y, and z axes are obtained, and a coordinate transformation matrix is ​​formed. Then, the unit stiffness matrix of the rod unit and the coordinate transformation matrix are processed by coordinate transformation, such as the coordinate transformation processing of the transpose matrix of the coordinate transformation matrix × the unit stiffness matrix of the rod unit × the coordinate transformation matrix, and the transformed unit stiffness matrix of the rod unit in the reference space coordinate system can be obtained. Finally, the numbers of the ball nodes at both ends of each rod unit in the overall structure corresponding to the three-dimensional reconstruction model of the current state space grid are placed in the corresponding positions of the overall stiffness matrix, and the overall stiffness matrix of the current grid can be obtained.

[0117] The internal force monitoring unit 160 is used to determine the stress analysis result, internal force analysis result and balance verification result corresponding to the current state space grid three-dimensional reconstruction model based on the current grid overall stiffness matrix and the current deformation.

[0118] In this embodiment, after determining the current overall stiffness matrix of the spatial grid and the current deformation, stress analysis, internal force analysis and balance verification can be performed to obtain corresponding stress analysis results, internal force analysis results and balance verification results.

[0119] In one embodiment, the internal force monitoring unit 160 is specifically used for:

[0120] Obtaining the node displacement corresponding to the current deformation of each rod unit in the three-dimensional reconstruction model of the current state space grid, and obtaining the rod unit length of each rod unit, based on the displacement component of the node displacement of each rod unit in the axial direction of the rod unit multiplied by the elastic modulus of the rod unit divided by the rod unit length, to obtain the stress value of each rod unit, and compose the stress analysis result;

[0121] Obtaining the stress value of each bar unit in the three-dimensional reconstruction model of the current state space grid and multiplying it by the cross-sectional area of ​​the corresponding bar unit to obtain the internal force value of each bar unit and form the internal force analysis result;

[0122] Based on the current overall stiffness matrix of the truss, the node displacement corresponding to the current deformation and the preset node force determination strategy, the node force corresponding to each ball node in the three-dimensional reconstruction model of the current state space truss is determined, and the node force corresponding to each ball node is compared with the preset node force threshold to obtain the balance verification result.

[0123] In this embodiment, since the node displacement corresponding to each bar unit in the current state space grid three-dimensional reconstruction model in the current deformation and the overall stiffness matrix of the current grid have been determined before, the stress value and internal force value of each bar unit can be calculated respectively in combination with the bar unit length and the elastic modulus of each bar unit. In addition, the node force corresponding to each ball node in the current state space grid three-dimensional reconstruction model is determined in combination with the node force determination strategy (such as the static equilibrium equation method), and the node force corresponding to each ball node is compared with the preset node force threshold to obtain the balance verification result. Specifically, if it is determined that the node force corresponding to each ball node is less than the preset node force threshold, the balance verification pass result is used as the balance verification result; if it is determined that the node force corresponding to a ball node is greater than the node force threshold, the node number of the corresponding ball node in the current state space grid three-dimensional reconstruction model is obtained, and the node number and the balance verification failure result are used as the balance verification result.

[0124] It can be seen that the implementation example of the device can obtain the three-dimensional reconstruction models corresponding to the initial state and the current state of the space truss respectively based on image acquisition and three-dimensional reconstruction, and then determine the current deformation of the ball node and the current overall stiffness matrix of the truss by combining the two three-dimensional reconstruction models, and determine the stress analysis results, internal force analysis results and balance verification results obtained by analysis. There is no need to stick strain gauges at the ball nodes, which not only reduces the construction cost, but also improves the efficiency and accuracy of obtaining the relevant results of the internal force monitoring of the space truss.

[0125] The above-mentioned spatial grid internal force monitoring device based on three-dimensional reconstruction can be implemented in the form of a computer program. The computer program can be used in Fig. 9 Runs on the computer device shown.

[0126] See also Fig. 9 , Fig. 9 The schematic block diagram of a computer device provided by an embodiment of the present invention is shown in FIG. The computer device integrates any of the three-dimensional reconstruction-based space grid internal force monitoring devices provided by an embodiment of the present invention.

[0127] See also Fig. 9 The computer device 400 includes a processor 402 , a memory and a network interface 405 connected via a system bus 401 , wherein the memory may include a storage medium 403 and an internal memory 404 .

[0128] The storage medium 403 can store an operating system 4031 and a computer program 4032. The computer program 4032 includes program instructions, and when the program instructions are executed, the processor 402 can execute the above-mentioned spatial grid internal force monitoring method based on three-dimensional reconstruction.

[0129] The processor 402 is used to provide computing and control capabilities to support the operation of the entire computer device.

[0130] The internal memory 404 provides an environment for the operation of the computer program 4032 in the storage medium 403. When the computer program 4032 is executed by the processor 402, the processor 402 can execute the above-mentioned spatial grid internal force monitoring method based on three-dimensional reconstruction.

[0131] The network interface 405 is used to communicate with other devices over the network. Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0132] The processor 402 is used to run the computer program 4032 stored in the memory to implement the above-mentioned method for monitoring the internal force of a spatial grid based on three-dimensional reconstruction.

[0133] It should be understood that in the embodiment of the present invention, the processor 402 may be a central processing unit (CPU), and the processor 402 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0134] It can be understood by those skilled in the art that all or part of the processes in the method for implementing the above embodiment can be completed by instructing the relevant hardware through a computer program. The computer program includes program instructions, and the computer program can be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in the computer device to implement the process steps of the embodiment of the above method.

[0135] Therefore, the present invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, wherein the computer program includes program instructions. When the program instructions are executed by a processor, the processor executes the above-mentioned spatial grid internal force monitoring method based on three-dimensional reconstruction.

[0136] The computer-readable storage medium may be a USB flash drive, a mobile hard disk, a read-only memory (ROM), a magnetic disk, or an optical disk, etc., which are computer-readable storage media that can store program codes.

[0137] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0138] In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of each unit is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed.

[0139] The steps in the method of the embodiment of the present invention can be adjusted in order, combined and deleted according to actual needs. The units in the device of the embodiment of the present invention can be combined, divided and deleted according to actual needs. In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0140] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, terminal, or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention.

[0141] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for monitoring internal forces of a space grid based on three-dimensional reconstruction, characterized in that: include: In response to the spatial grid internal force monitoring instruction, a three-dimensional reconstruction model of the initial state spatial grid is obtained; wherein the three-dimensional reconstruction model of the initial state spatial grid is obtained by three-dimensionally reconstructing the spatial grid image collected when the spatial grid is initially spliced ​​and not placed in the actual installation position; Obtaining a three-dimensional reconstruction model of the space grid in the current state; wherein the three-dimensional reconstruction model of the space grid in the current state is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position; Acquire a three-dimensional reconstruction model alignment model between the current state space grid three-dimensional reconstruction model and the initial state space grid three-dimensional reconstruction model based on a preset grid model alignment strategy; Determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation corresponding to the current state space grid three-dimensional reconstruction model; Acquire the current grid overall stiffness matrix corresponding to the three-dimensional reconstruction model of the current state space grid; Based on the current grid overall stiffness matrix and the current deformation, determine the stress analysis results, internal force analysis results and balance verification results corresponding to the current state space grid three-dimensional reconstruction model; Wherein, based on the preset three-dimensional reconstruction strategy and the initial state image set of the space grid, the three-dimensional reconstruction model of the initial state space grid is obtained, including: Extracting image feature points from each frame of the spatial grid initial state image in the spatial grid initial state image set according to a preset feature point extraction model, and performing feature point matching processing on multiple image feature points to establish a feature point correspondence relationship between the feature points of each image; The corresponding relationship of the feature points is combined with the camera parameters of the image acquisition device to determine the camera motion trajectory, and the multi-view geometric relationship of the initial state image of each frame of the space grid in the initial state image set of the space grid is determined according to the camera motion trajectory; wherein the camera parameters of the image acquisition device include at least a basic matrix and an essential matrix; According to the feature point correspondence relationship between the feature points of each image and the multi-view geometric relationship, the image feature points of the initial state image of each frame of the spatial grid are converted into an initial point cloud, and then a Poisson dense reconstruction process is performed to obtain an initial target point cloud, and the initial target point cloud is used as the initial state spatial grid 3D reconstruction model; The current state space grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position based on the three-dimensional reconstruction strategy.

2. The method according to claim 1, characterized in that: The method of obtaining a three-dimensional reconstruction model alignment model between the current state space grid three-dimensional reconstruction model and the initial state space grid three-dimensional reconstruction model based on a preset grid model alignment strategy includes: Based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node is selected from the initial state space grid three-dimensional reconstruction model and used as a reference origin; Acquire at least two reference rod elements having one end connected to a vertex ball node corresponding to the reference origin based on the rod screening sub-strategy in the grid model alignment strategy; The current state vertex ball nodes corresponding to the reference origin in the current state space grid three-dimensional reconstruction model are aligned, and the current state rod units corresponding to at least two reference rod units in the current state space grid three-dimensional reconstruction model are aligned to obtain the three-dimensional reconstruction model alignment model.

3. The method according to claim 1, characterized in that The method of obtaining a three-dimensional reconstruction model alignment model between the current state space grid three-dimensional reconstruction model and the initial state space grid three-dimensional reconstruction model based on a preset grid model alignment strategy includes: Based on the vertex screening sub-strategy in the grid model alignment strategy, a vertex ball node is selected from the initial state space grid three-dimensional reconstruction model and used as a reference origin; Acquire the current state vertex ball node corresponding to the reference origin in the current state space grid three-dimensional reconstruction model, and align it with the reference origin; Obtain the remaining vertex ball node set after removing the current state vertex ball node in the current state space grid three-dimensional reconstruction model, and obtain the corresponding translated current state space grid three-dimensional reconstruction model under the state that satisfies the sum of the squares of the distances between each vertex ball node in the remaining vertex ball node set and the corresponding vertex ball nodes in the initial state space grid three-dimensional reconstruction model is minimum, and form the three-dimensional reconstruction model alignment model with the initial state space grid three-dimensional reconstruction model.

4. The method according to claim 1, characterized in that The method of determining the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determining the current deformation amount corresponding to the current state space grid three-dimensional reconstruction model, includes: Based on the three-dimensional reconstruction model alignment model and the reference space coordinate system corresponding to the initial state space grid three-dimensional reconstruction model, the displacement of each ball node in the current state space grid three-dimensional reconstruction model relative to the corresponding ball node in the initial state space grid three-dimensional reconstruction model is determined, and the current deformation is composed of the displacement of each ball node in the current state space grid three-dimensional reconstruction model.

5. The method according to claim 4, characterized in that The step of obtaining a current grid overall stiffness matrix corresponding to the current state space grid three-dimensional reconstruction model comprises: For each rod element in the three-dimensional reconstruction model of the current state space grid, determine the unit stiffness matrix of the rod element in the local coordinate system according to the ball node numbers at both ends of the rod element; Determine the transformed unit stiffness matrix of the bar unit in the reference space coordinate system based on the coordinate transformation matrix between the local coordinate system and the reference space coordinate system corresponding to the three-dimensional reconstruction model of the initial state space grid; According to the corresponding order of the ball node numbers at both ends of each rod unit in the current state space grid three-dimensional reconstruction model, the converted unit stiffness matrix of each rod unit in the current state space grid three-dimensional reconstruction model is spliced ​​to form the current grid overall stiffness matrix.

6. The method according to claim 1, characterized in that The determining of the stress analysis result, internal force analysis result and balance verification result corresponding to the three-dimensional reconstruction model of the current state space grid based on the current grid overall stiffness matrix and the current deformation includes: Obtaining the node displacement corresponding to the current deformation of each rod unit in the three-dimensional reconstruction model of the current state space grid, and obtaining the rod unit length of each rod unit, based on the displacement component of the node displacement of each rod unit in the axial direction of the rod unit multiplied by the elastic modulus of the rod unit divided by the rod unit length, to obtain the stress value of each rod unit, and compose the stress analysis result; Obtaining the stress value of each bar unit in the three-dimensional reconstruction model of the current state space grid and multiplying it by the cross-sectional area of ​​the corresponding bar unit to obtain the internal force value of each bar unit and form the internal force analysis result; Based on the current overall stiffness matrix of the truss, the node displacement corresponding to the current deformation and the preset node force determination strategy, the node force corresponding to each ball node in the three-dimensional reconstruction model of the current state space truss is determined, and the node force corresponding to each ball node is compared with the preset node force threshold to obtain the balance verification result.

7. The method according to claim 6, characterized in that The step of comparing the node force corresponding to each ball node with a preset node force threshold and obtaining the balance verification result includes: If it is determined that the node forces corresponding to the various spherical nodes are all less than the preset node force threshold, the balance verification passing result is used as the balance verification result; If it is determined that the node force corresponding to the ball node is greater than the node force threshold, the node number of the corresponding ball node in the three-dimensional reconstruction model of the current state space grid is obtained, and the node number and the balance verification failure result are used as the balance verification result.

8. A spatial grid internal force monitoring device based on three-dimensional reconstruction, characterized in that: include: An initial grid three-dimensional reconstruction model acquisition unit is used to respond to the spatial grid internal force monitoring instruction to acquire an initial state spatial grid three-dimensional reconstruction model; wherein the initial state spatial grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the spatial grid image collected when the spatial grid is initially spliced ​​and not placed in the actual installation position; A current grid three-dimensional reconstruction model acquisition unit is used to acquire a current state space grid three-dimensional reconstruction model; wherein the current state space grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position; A 3D reconstruction model alignment model acquisition unit, used for acquiring a 3D reconstruction model alignment model between the current state space grid 3D reconstruction model and the initial state space grid 3D reconstruction model based on a preset grid model alignment strategy; A current deformation amount determination unit is used to determine the displacement of each ball node in the current state space grid three-dimensional reconstruction model and the corresponding ball node in the initial state space grid three-dimensional reconstruction model based on the three-dimensional reconstruction model alignment model, and determine the current deformation amount corresponding to the current state space grid three-dimensional reconstruction model; A stiffness matrix acquisition unit, used to acquire the current grid overall stiffness matrix corresponding to the three-dimensional reconstruction model of the current state space grid; An internal force monitoring unit, used to determine the stress analysis result, internal force analysis result and balance verification result corresponding to the three-dimensional reconstruction model of the current state space grid based on the current grid overall stiffness matrix and the current deformation; Wherein, based on the preset three-dimensional reconstruction strategy and the initial state image set of the space grid, the three-dimensional reconstruction model of the initial state space grid is obtained, including: Extracting image feature points from each frame of the spatial grid initial state image in the spatial grid initial state image set according to a preset feature point extraction model, and performing feature point matching processing on multiple image feature points to establish a feature point correspondence relationship between the feature points of each image; The corresponding relationship of the feature points is combined with the camera parameters of the image acquisition device to determine the camera motion trajectory, and the multi-view geometric relationship of the initial state image of each frame of the space grid in the initial state image set of the space grid is determined according to the camera motion trajectory; wherein the camera parameters of the image acquisition device include at least a basic matrix and an essential matrix; According to the feature point correspondence relationship between the feature points of each image and the multi-view geometric relationship, the image feature points of the initial state image of each frame of the spatial grid are converted into an initial point cloud, and then a Poisson dense reconstruction process is performed to obtain an initial target point cloud, and the initial target point cloud is used as the initial state spatial grid 3D reconstruction model; The current state space grid three-dimensional reconstruction model is obtained by three-dimensionally reconstructing the space grid image collected when the space grid is spliced ​​and placed in the actual installation position based on the three-dimensional reconstruction strategy.

9. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and the processor implements the steps of the spatial grid internal force monitoring method based on three-dimensional reconstruction according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for monitoring internal forces of a space grid based on three-dimensional reconstruction as described in any one of claims 1 to 7 are implemented.

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