Virtual simulation system design method of spacecraft unfolding mechanism

Abstract

The invention discloses a virtual simulation system design method for a spacecraft unfolding mechanism, and belongs to the technical field of spacecraft unfolding mechanism simulation. The problems that an existing spacecraft unfolding mechanism is long in ground simulation period and poor in flexibility are solved. Comprising the steps of obtaining 2D position coordinates under a pixel coordinate system by adopting a PnP algorithm based on world coordinate system 3D position coordinates of feature points in a real scene point cloud model; obtaining a first coordinate transformation matrix from an AR equipment coordinate system to a world coordinate system in combination with the internal reference of the AR equipment; a real space coordinate system is established, a second coordinate transformation matrix from the AR equipment coordinate system to the real space coordinate system is obtained through calculation, and the pose of the expansion mechanism virtual model under the AR equipment coordinate system is obtained based on the second coordinate transformation matrix; a virtual simulation framework and a real scene point cloud model are fused to obtain a fused virtual framework, an expansion mechanism virtual model is fixedly arranged on the fused virtual framework to obtain a virtual simulation system, and a selected rendering position in a real scene is rendered through AR equipment. The method is used for simulation of the spacecraft unfolding mechanism.

Description

Technical Field

[0001] The invention relates to a virtual simulation system design method for a spacecraft deployment mechanism, and belongs to the technical field of spacecraft deployment mechanism simulation. Background Art

[0002] For large spacecraft deployment mechanisms, traditional ground simulation experimental methods rely on the construction of complex large-scale simulation mechanical structure platforms, which has significant limitations. First, it takes a long time to build a matching large-scale simulation mechanical structure platform. From design, manufacturing to installation and debugging, the entire process often takes months or even longer, which greatly limits the flexibility and response speed of the R&D cycle. Secondly, the cost is high. The construction and maintenance costs of the simulation platform are extremely high. This includes not only the initial construction investment, but also the subsequent operation and maintenance costs. The high cost limits frequent experiments and iterations, thereby affecting the speed and efficiency of technological progress. In addition, this method lacks flexibility. Once the simulation platform is built, its structure and function are relatively fixed, and it is difficult to adapt to the ever-changing experimental simulation needs. This lack of flexibility limits the diversity and innovation of experimental design.

[0003] In addition, existing research on unfolding mechanism simulation mainly focuses on the field of computer simulation, using the powerful computing power of computers to obtain the required data. However, there are still some deficiencies in the visualization of simulation. In the project verification stage, experts from various fields are needed to discuss and determine the specific plan. It is difficult for non-experts in related fields to intuitively feel the dynamic changes and details of the simulation process by relying solely on data. Summary of the invention

[0004] In view of the problem that the existing ground simulation period of a spacecraft deployment mechanism is long and the flexibility is poor, the present invention provides a virtual simulation system design method for a spacecraft deployment mechanism.

[0005] A virtual simulation system design method for a spacecraft deployment mechanism of the present invention comprises:

[0006] Based on the real scene image captured by the AR device, a real scene point cloud model is established; based on the 3D position coordinates of the feature points in the real scene point cloud model in the world coordinate system, the PnP algorithm is used to calculate the 2D position coordinates of the feature points in the real scene image in the pixel coordinate system; then combined with the AR device internal parameters, the first coordinate conversion matrix from the AR device coordinate system to the world coordinate system is calculated; the position and posture relationship of the AR device relative to the world coordinate system is determined by the first coordinate conversion matrix;

[0007] Create a spatial anchor point in the real scene, and establish a real space coordinate system based on the spatial anchor point; calculate a second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system; calculate the position and posture of the virtual model of the unfolding mechanism in the AR device coordinate system according to the second coordinate transformation matrix and the selected rendering position of the virtual model of the unfolding mechanism in the real space coordinate system;

[0008] Establish a full system data model of the spacecraft deployment mechanism, and build a virtual simulation framework based on the full system data model;

[0009] The virtual simulation framework is integrated with the point cloud model of the real scene to obtain a fused virtual framework; the virtual model of the unfolding mechanism is fixed on the fused virtual framework to form a virtual simulation system; under the premise that the position and posture relationship of the AR device relative to the world coordinate system is determined, the virtual simulation system can render the selected rendering position in the real scene, thus completing the construction of the virtual simulation system.

[0010] According to the method for designing a virtual simulation system for a spacecraft deployment mechanism of the present invention, after the virtual simulation system is built, the state switching of the deployment mechanism virtual model is controlled by driving force to achieve performance testing of the deployment mechanism virtual model.

[0011] According to the virtual simulation system design method of the spacecraft deployment mechanism of the present invention, the first coordinate transformation matrix is ​​expressed as [Rt], where R is the rotation parameter matrix and t is the translation parameter matrix;

[0012] Then the AR device coordinate system (O c X c Y c Z c ) and the world coordinate system (O w X w Y w Z w ) is:

[0013]

[0014] Where [X w Y w Z w ] T is the 3D position coordinate of the feature point in the world coordinate system, and the corresponding homogeneous coordinate is [X w Y w Z w 1] T ;[X c Y c Z c ] T is the 3D position coordinate of the feature point in the AR device coordinate system;

[0015] Set the 2D position coordinates of the feature point in the pixel coordinate system to [u c v c ] T , the corresponding homogeneous coordinates are [u c v c 1] T , the AR device internal parameter is K, then the pixel coordinate system and the world coordinate system (O w X w Y w Z w ) is:

[0016]

[0017] Where z c is the linear relationship coefficient from high dimension to low dimension;

[0018] Expand the above formula to get the expanded formula:

[0019]

[0020] In the formula is the parameter coefficient in the rotation parameter matrix R, is the parameter coefficient in the translation parameter matrix t;

[0021] Express the expansion as a system of equations:

[0022] z c u c =f 11 X w +f 12 Y w +f 13 Z w +f 14 ,

[0023] z c v c =f 21 X w +f 22 Y w +f 23 Z w +f 24 ,

[0024] z c =f 31 X w +f 32 Y w +f 33 Z w +f 34 ,

[0025] Eliminate the linear relationship coefficient z from high dimension to low dimensionc Then we get:

[0026] f 11 X w +f 12 Y w +f 13 Z w +f 14 -f 31 X w u c -f 32 Y w u c -f 33 Z w u c -f 34 u c =0,

[0027] f 21 X w +f 22 Y w +f 23 Z w +f 24 -f 31 X w v c -f 32 Y w v c -f 33 Z w v c -f 34 v c =0,

[0028] Assume [u c v c ]There are N groups of matching points [u c1 v c1 ] to [u cN v cN ],[X w Y w Z w ]There are N sets of matching points [X w1 Y w1 Z w1 ] to [X wN Y wN Z wN ],get:

[0029]

[0030] Solved and

[0031] make

[0032] Combining F = [KR Kt], we get the rotation parameter matrix R and translation parameter matrix t as:

[0033]

[0034]

[0035] According to the virtual simulation system design method of the spacecraft deployment mechanism of the present invention, the solution is obtained and The methods include:

[0036] If N = 6, directly solve the linear equations;

[0037] If N>6:

[0038] set up:

[0039]

[0040] Then AF=0;

[0041] Calculate the least squares solution under the constraint of |F|=1, and then decompose A using the SVD method:

[0042] A=UDV T ,

[0043] Where A is a 2N×12 matrix, U is a 2N×2N matrix after decomposition, D is a 2N×12 matrix after decomposition, and V is a 12×12 matrix after decomposition; the last column of matrix V gives and The solution.

[0044] According to the virtual simulation system design method of the spacecraft deployment mechanism of the present invention, the method of establishing the real space coordinate system is:

[0045] Select spatial anchor points (A, B, C, D) corresponding to the feature points in the real scene, and establish a real space coordinate system based on the spatial anchor points;

[0046] In the AR device coordinate system, the three inconsistency anchor point vectors corresponding to the spatial anchor points (A, B, C, D) are:

[0047]

[0048] Where (a1, b1, c1) is the corresponding difference between the coordinate values ​​of spatial anchor point B and spatial anchor point A in the AR device coordinate system; (a2, b2, c2) is the corresponding difference between the coordinate values ​​of spatial anchor point C and spatial anchor point A in the AR device coordinate system; (a3, b3, c3) is the corresponding difference between the coordinate values ​​of spatial anchor point D and spatial anchor point A in the AR device coordinate system;

[0049] The Schmidt orthogonalization algorithm is used to orthogonally normalize the three inequitable surface anchor point vectors:

[0050]

[0051] Take r = 3,

[0052]

[0053] in:

[0054] J1=a1 2 +b1 2 +c1 2 ,

[0055] J2=a2 2 +b2 2 +c2 2 ,

[0056] H1=a1a2+b1b2+c1c2,

[0057] H2=a1a3+b1b3+c1c3,

[0058] H3=a2a3+b2b3+c2c3,

[0059] standardization:

[0060]

[0061] In the real scene, the spatial anchor point A is used as the coordinate origin O r ,by The vector direction is X r Axis direction, The vector direction is Y r Axis direction, The vector direction is Z r Axis direction, establish the real space coordinate system (O r X r Y r Z r ).

[0062] Beneficial effects of the invention: The method of the invention realizes virtual experiment simulation based on digital twins, further develops and improves simulation visualization technology, uses AR for reality enhancement, and more intuitively and vividly displays the simulation process, thereby improving the practicality and authenticity of the simulation. The method of the invention performs relevant simulations of large structural parts without the need for real experimental institutions and experimental environments, and can verify the relevant content of ground simulation experiments in advance, with the characteristics of short simulation cycle and strong flexibility.

[0063] The method of the present invention is aimed at large-scale structural parts of spacecraft. It only needs to build a virtual simulation environment in a real field based on the PnP algorithm to verify the relevant content of the ground simulation experiment in advance, which can greatly shorten the engineering cycle and reduce engineering costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a schematic diagram of the conversion relationship between the AR device coordinate system and the world coordinate system;

[0065] Figure 2 It is a schematic diagram of the relationship between the AR device coordinate system, the pixel coordinate system and the world coordinate system. In the figure, f represents the AR device coordinate system, c represents the device coordinate system, and w represents the world coordinate system.

[0066] Figure 3 This is a schematic diagram of creating spatial anchor points in a real scene;

[0067] Figure 4 It is a schematic diagram of using Schmidt orthogonalization algorithm to orthogonally normalize the anchor point vectors of three inequitable surfaces in a real scene;

[0068] Figure 5 is the real space coordinate system in the real scene (O r X r Z r Z r )

[0069] Figure 6 It is a rendering schematic diagram of the virtual model of the deployment mechanism in the first orientation in the real space coordinate system;

[0070] Figure 7 It is a rendering diagram of the virtual model of the deployment mechanism in the second orientation in the real space coordinate system;

[0071] Figure 8 is a schematic diagram of a full system data model of an antenna in an embodiment;

[0072] Fig. 9 Yes Figure 8 The model diagram after the whole system data model is transformed into a faceted model;

[0073] Fig.10is a schematic diagram of a solidworks model of a ground deployment device in an embodiment;

[0074] Fig.11 is a schematic diagram of a single antenna for constructing a large antenna model in an embodiment;

[0075] Fig.12 is a schematic diagram of a four-fold antenna for constructing a large antenna model in an embodiment;

[0076] Fig.13 is a schematic diagram of a large antenna virtual model and a ground deployment virtual device in an embodiment;

[0077] Fig.14 It is a rendering of the virtual simulation environment;

[0078] Fig.15 It is a schematic diagram of the folded state of the four-fold antenna in a virtual simulation environment;

[0079] Fig.16 This is a schematic diagram of a four-fold antenna being unfolded once in a virtual simulation environment;

[0080] Fig.17 This is a schematic diagram of the secondary unfolding of the four-fold antenna in a virtual simulation environment. DETAILED DESCRIPTION

[0081] 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 only 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.

[0082] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0083] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0084] Specific implementation method 1. Combination Figures 1 to 7 As shown, the present invention provides a virtual simulation system design method for a spacecraft deployment mechanism, comprising:

[0085] Based on the real scene image captured by the AR device, a real scene point cloud model is established; based on the 3D position coordinates of the feature points in the real scene point cloud model in the world coordinate system, the PnP algorithm is used to calculate the 2D position coordinates of the feature points in the real scene image in the pixel coordinate system; then combined with the AR device internal parameters, the first coordinate conversion matrix from the AR device coordinate system to the world coordinate system is calculated; the position and posture relationship of the AR device relative to the world coordinate system is determined by the first coordinate conversion matrix;

[0086] Create a spatial anchor point in the real scene, and establish a real space coordinate system based on the spatial anchor point; calculate a second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system; calculate the position and posture of the virtual model of the unfolding mechanism in the AR device coordinate system according to the second coordinate transformation matrix and the selected rendering position of the virtual model of the unfolding mechanism in the real space coordinate system;

[0087] Establish a full system data model of the spacecraft deployment mechanism, and build a virtual simulation framework based on the full system data model;

[0088] The virtual simulation framework is integrated with the point cloud model of the real scene to obtain a fused virtual framework; the virtual model of the unfolding mechanism is fixed on the fused virtual framework to form a virtual simulation system; under the premise that the position and posture relationship of the AR device relative to the world coordinate system is determined, the virtual simulation system can render the selected rendering position in the real scene, thus completing the construction of the virtual simulation system.

[0089] In this embodiment, the real scene images collected include multi-dimensional photo sets or GoPro panoramic camera images, and a real scene point cloud model is generated through a 3D reconstruction algorithm. Based on the feature points of the point cloud model, or feature points constructed by other methods, PnP (Perspective-n-Point) is used to solve the corresponding points from 3D to 2D.

[0090] Furthermore, after the virtual simulation system is built, the state switching of the virtual model of the deployment mechanism is controlled by driving force to achieve performance testing of the virtual model of the deployment mechanism.

[0091] PnP describes how to estimate the pose of an AR device when N 3D feature points and their positions are known. If the 3D position of a feature point in two images is known, at least 3 point pairs (and at least one additional verification point verification result) are required to calculate the motion of the AR device. The 3D position of the feature point can be determined by triangulation or the depth map of the RGB-D camera.

[0092] The geometric structure of the PnP problem is as follows Figure 1 As shown, given the coordinates of the 3D point and the corresponding 2D point and the intrinsic parameter matrix, the posture of the AR device is solved.

[0093] Known: coordinates of N points in the world coordinate system P1, P2...P N , corresponding point pixel coordinates p1, p2...p N , AR device internal parameter K.

[0094] In this embodiment, combined with Figure 1 and Figure 2 As shown, the first coordinate transformation matrix is ​​expressed as [Rt], where R is the rotation parameter matrix and t is the translation parameter matrix;

[0095] Then the AR device coordinate system (O c X c Y c Z c ) and the world coordinate system (O w X w Y w Z w ) is:

[0096]

[0097] Assume that the AR device has been calibrated, where [X w Y w Z w ] T is the 3D position coordinate of the feature point in the world coordinate system, and the corresponding homogeneous coordinate is [X w Y w Z w 1] T ;[X c Y c Z c ] T is the 3D position coordinate of the feature point in the AR device coordinate system;

[0098] Set the 2D position coordinates of the feature point in the pixel coordinate system to [U c V c ] T , the corresponding homogeneous coordinates are [U c V c 1] T , the AR device internal parameter is k, such as Figure 2 As shown, the pixel coordinate system and the world coordinate system (o w x w Y w Z w ) is:

[0099]

[0100] Where z c is the linear relationship coefficient from high dimension to low dimension;

[0101] Expand the above formula to get the expanded formula:

[0102]

[0103] In the formula is the parameter coefficient in the rotation parameter matrix R, is the parameter coefficient in the translation parameter matrix t;

[0104] Express the expansion as a system of equations:

[0105] z c u c =F 11 X w +f 12 Y w +f 13 Z w +f 14 ,

[0106] z c v c =F 21 x w +f 22 Y w +f 23 Z w +f 24 ,

[0107] z c =F 31 x w +F 32 y w +F 33 z w +F 34 ,

[0108] Eliminate the linear relationship coefficient z from high dimension to low dimension c Then we get:

[0109] f 11 X w +F 12 y w +F 13 z w +f 14 -f 31 X w u c -f 32 Y w u c -f 33 Z w u c -f 34 u c =0,

[0110] f 21 X w +F 22 y w +F 23 z w +f 24 -f 31 X w v c -F 32 y w V c -F 33 z w v c -F 34 v c =0,

[0111] Each set of 3D-2D matching points corresponds to two equations, with a total of 12 unknowns, requiring at least 6 sets of matching points. c v c ]There are N groups of matching points [u c1 v c1 ] to [u cN v cN ],[X w Y w Z w ]There are N sets of matching points [X w1 Y w1 Z w1 ] to [X wN Y wN z wN ],get:

[0112]

[0113] Solved and make Combining F = [KR Kt], we get the rotation parameter matrix R and translation parameter matrix t as:

[0114]

[0115] Solved and The methods include:

[0116] If N = 6, directly solve the linear equations;

[0117] If N>6:

[0118] set up:

[0119]

[0120] Write the equation with N sets of matching points in matrix form, then AF=0;

[0121] Calculate the least squares solution under the constraint of |F|=1, and then decompose A using the SVD method:

[0122] A=UDV T ,

[0123] Where A is a 2N×12 matrix, U is a 2N×2N matrix after decomposition, D is a 2N×12 matrix after decomposition, and V is a 12×12 matrix after decomposition; the last column of matrix V gives and The solution.

[0124] Thus, a first coordinate transformation matrix from the AR device coordinate system to the world coordinate system is obtained, and the position and posture relationship of the AR device relative to the world coordinate system is determined according to the first coordinate transformation matrix.

[0125] Virtual model positioning based on spatial anchor points and posture transformation:

[0126] To render and generate a virtual model at a specific location in the real space, it is also necessary to convert the virtual model between the real space coordinate system and the AR device space coordinate system. First, a spatial anchor point must be created, and a real space coordinate system must be established based on the spatial anchor point. Then, based on the conversion relationship between the real space coordinate system and the AR device coordinate system, the position and posture of the virtual model in the AR device coordinate system is calculated, and then the virtual model is rendered at a specific location.

[0127] To create a spatial anchor point:

[0128] Characteristics of spatial anchor points: spatial anchor points are anchored on objects in real space based on feature point matching, and do not change with the position and posture of the AR device, but are only related to the position and posture of the real object where the feature point is located. Figure 3 The spatial anchor point created.

[0129] Going a step further, combined Figures 3 to 7 As shown, the method of establishing the real space coordinate system is:

[0130] Select spatial anchor points (A, B, C, D) corresponding to the feature points in the real scene, and establish a real space coordinate system based on the spatial anchor points;

[0131] In the AR device coordinate system, the three inconsistency anchor point vectors corresponding to the spatial anchor points (A, B, C, D) are:

[0132]

[0133] Where (a1, b1, c1) is the corresponding difference between the coordinates of the spatial anchor point B and the spatial anchor point A in the AR device coordinate system; (a2, b2, c2) is the corresponding difference between the coordinates of the spatial anchor point C and the spatial anchor point A in the AR device coordinate system; (a . ,b . ,c . ) is the corresponding difference between the coordinate values ​​of the spatial anchor point D and the spatial anchor point A in the AR device coordinate system;

[0134] like Figure 4 As shown, the Schmidt orthogonalization algorithm is used to orthogonally normalize the three inconsistency surface anchor point vectors:

[0135]

[0136] Because it is a three-dimensional space, we take r = 3.

[0137]

[0138] in:

[0139] J1=a1 2 +b1 2 +c1 2 ,

[0140] J2=a2 2 +b2 2 +c2 2 ,

[0141] H1=a1a2+b1b2+c1c2,

[0142] H2=a1a3+b1b3+c1c3,

[0143] H3=a2a3+b2b3+c2c3,

[0144] standardization:

[0145]

[0146] In the real scene, the spatial anchor point A is used as the coordinate origin O r ,by The vector direction is X r Axis direction, The vector direction is Y r Axis direction, The vector direction is Z r Axis direction, establish the real space coordinate system (O r X r Y r Z r ),like Figure 5 Middle red coordinate system.

[0147] Going further, calculate the virtual model pose coordinates in the AR device coordinate system:

[0148] The method for calculating the second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system is:

[0149] According to the establishment process of the real space coordinate system, the AR device coordinate system (O c X c Y c Z c ) and the real space coordinate system (O r X r Y r Z r ) is:

[0150]

[0151] Where M is the second coordinate transformation matrix:

[0152]

[0153] The pose coordinates of the virtual model of the unfolding mechanism in the AR device coordinate system are obtained.

[0154] The method for solving the pose coordinates of the virtual model of the unfolding mechanism in the AR device coordinate system is:

[0155] Assume that at a specific position in the real space, the coordinate system of the virtual model of the unfolding mechanism is ( b X b Y b Z b ), its position coordinate in the real space coordinate system is (X r1 ,Y r1 ,Z r1 ), the position of the virtual model of the unfolding mechanism in the real space coordinate system is expressed by four infinite numbers:

[0156] Solve the position coordinates (X c1 ,Y c1 ,Z c1 ):

[0157]

[0158] The coordinates of the body are (O b X b Y b Z b ) and the real space coordinate system (O r Xr Y r Z r ) is:

[0159]

[0160] Where Γ The coordinate transformation matrix from the real space coordinate system to the body coordinate system:

[0161]

[0162] Combining the second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system, we can get the transformation relationship between the body coordinate system and the AR device coordinate system:

[0163]

[0164] In the formula To unfold the virtual model of the mechanism in the AR device coordinate system:

[0165]

[0166] The coordinate transformation matrix from the AR device coordinate system to the body coordinate system;

[0167] The equation obtained from the above conversion relationship is:

[0168]

[0169] Solve and obtain the position and posture of the virtual model of the unfolding mechanism in the AR device coordinate system

[0170] Figure 6 and Figure 7 The figure shows a test example. The posture of the virtual model of the unfolding mechanism is anchored to the real space coordinate system. The change of the AR device posture will not change the posture of the virtual model of the unfolding mechanism. Instead, the posture of the virtual model of the unfolding mechanism in the AR device coordinate system is calculated and rendered in real time through an algorithm.

[0171] Going a step further, combined Figures 8 to 17 As shown, according to the application scenario, mission requirements and performance indicators of the spacecraft deployment mechanism, the design data is established and documented to obtain a data model of the entire system;

[0172] Establish the data conversion relationship between the whole system data model and the virtual simulation framework, and generate the virtual simulation framework through the Solidworks module by using the 3dmax data interface to convert the whole system data model into a virtual simulation framework.

[0173] The virtual simulation framework includes a truss, a hanger, a flip beam and a cylinder; the virtual simulation framework is integrated with the real scene point cloud model to obtain a fused virtual framework;

[0174] The virtual model of the unfolding mechanism includes a hinge mechanism and a fixing frame;

[0175] The virtual model of the unfolding mechanism is fixed on the fused virtual frame to form a virtual simulation system.

[0176] After the virtual simulation system is built, a driving force is added to the hinge mechanism of the virtual model of the unfolding mechanism, and a locking mechanism is added to the predetermined unfolding position of the virtual model of the unfolding mechanism to control the virtual model of the unfolding mechanism to unfold twice under the action of the driving force, thereby realizing the performance test of the virtual model of the unfolding mechanism.

[0177] Example:

[0178] Construction of virtual simulation framework based on unity3d:

[0179] Taking the deployment mechanism virtual model of a large antenna as an example, a full system data model of the large antenna is established:

[0180] A large-scale antenna full system data model is established based on the antenna's mission requirements and performance indicators. First, a detailed mathematical model of the antenna system is constructed based on its application scenarios and performance indicators, such as communication distance, frequency range, gain, and beam width. Then, these subsystem models are integrated into a unified framework for the overall design of large antennas. The accuracy of the model is preliminarily verified by testing with simulation software. Finally, the entire model is documented to form a data model of the antenna full system, such as Figure 8 shown.

[0181] Then, the data conversion between the large antenna full system data model (Pro / E, Solidworks and UG models) and the large antenna virtual model is realized, including the data content extracted from the large antenna full system data model and its storage format. The construction of the large antenna virtual model is mainly based on 3dmax data interface technology. The 3dmax interface technology imports the three-dimensional model data in the Solidworks system through a neutral interface file and reconstructs the model data. The large antenna virtual model data uses parametric patch data. The use of patched model data greatly improves the model display speed and can realize the rapid display of large data models, such as Fig. 9 shown.

[0182] Construct a large antenna ground deployment device model:

[0183] First, use SolidWorks to build a ground deployment device model, including trusses, hangers, flip beams and cylinders. Fig.10 shown.

[0184] Build a large antenna model:

[0185] First, a single antenna board is modeled, such as Fig.11 As shown; then add the hinge mechanism and the fixing frame to obtain Fig.12 The large antenna is shown in four folds.

[0186] Virtual simulation environment construction

[0187] The four-fold large antenna model is fixed to the ground deployment device and assembled into a large antenna deployment full system data model. Then the data conversion between the large antenna full system data model (Pro / E, Solidworks and UG models) and the large antenna virtual model is realized, including the data content extracted from the large antenna full system data model and its storage format. The construction of the large antenna virtual model is mainly based on 3dmax data interface technology. The 3dmax interface technology imports the three-dimensional model data in the Solidworks system through a neutral interface file and reconstructs the model data. The large antenna virtual model data uses parametric patch data. The use of patched model data greatly improves the model display speed and can realize the rapid display of large data models. Fig.13 shown.

[0188] Import the virtual model into Unity and add a physical engine, such as adding driving force to the antenna connection hinge, adding collision properties, etc., to build a virtual simulation environment.

[0189] Virtual simulation system test:

[0190] The virtual simulation environment is rendered in the real space:

[0191] The constructed virtual simulation environment is integrated with the point cloud model, the program is packaged and copied into the AR device, and the program is run on the AR device to render and generate the virtual simulation environment. Fig.14 shown.

[0192] The four-fold antenna is unfolded in a virtual simulation environment:

[0193] After the virtual simulation environment is built, a driving force is added to the hinge, and a locking mechanism is added at the predetermined unfolding position to control the quadruple-fold antenna to unfold twice under the action of the driving force. Figures 15 to 17 shown.

[0194] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.

Claims

1. A virtual simulation system design method for a spacecraft deployment mechanism, characterized in that: include: Based on the real scene images collected by AR devices, a real scene point cloud model is established; Based on the 3D position coordinates of the feature points in the real scene point cloud model in the world coordinate system, the PnP algorithm is used to calculate the 2D position coordinates of the feature points in the real scene image in the pixel coordinate system; then combined with the AR device internal parameters, the first coordinate transformation matrix from the AR device coordinate system to the world coordinate system is calculated; the position and posture relationship of the AR device relative to the world coordinate system is determined by the first coordinate transformation matrix; Create spatial anchor points in the real scene and establish a real space coordinate system based on the spatial anchor points; A second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system is calculated; a position and posture of the virtual model of the unfolding mechanism in the AR device coordinate system is calculated according to the second coordinate transformation matrix and the selected rendering position of the virtual model of the unfolding mechanism in the real space coordinate system; Establish a full system data model of the spacecraft deployment mechanism, and build a virtual simulation framework based on the full system data model; The virtual simulation frame is integrated with the real scene point cloud model to obtain a fused virtual frame; The virtual model of the unfolding mechanism is fixed on the fused virtual frame to form a virtual simulation system; under the premise that the position and posture relationship of the AR device relative to the world coordinate system is determined, the virtual simulation system can render the selected rendering position in the real scene, thus completing the construction of the virtual simulation system.

2. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 1, characterized in that: After the virtual simulation system is built, the state switching of the virtual model of the deployment mechanism is controlled by the driving force to achieve the performance test of the virtual model of the deployment mechanism.

3. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 2, characterized in that: The first coordinate transformation matrix is ​​expressed as [Rt], where R is the rotation parameter matrix and t is the translation parameter matrix; Then the AR device coordinate system (O c X c Y c Z c ) and the world coordinate system (O w X w Y w Z w ) is: Where [X w Y w Z w ] T is the 3D position coordinate of the feature point in the world coordinate system, and the corresponding homogeneous coordinate is [X w Y w Z w 1] T ;[X c Y c Z c ] T is the 3D position coordinate of the feature point in the AR device coordinate system; Set the 2D position coordinates of the feature point in the pixel coordinate system to [u c v c ] T , the corresponding homogeneous coordinates are [u c v c 1] T , the AR device internal parameter is K, then the pixel coordinate system and the world coordinate system (O w X w Y w Z w ) is: Where z c is the linear relationship coefficient from high dimension to low dimension; Expand the above formula to get the expanded formula: In the formula is the parameter coefficient in the rotation parameter matrix R, is the parameter coefficient in the translation parameter matrix t; Express the expansion as a system of equations: z c u c =f 11 X w +f 12 Y w +f 13 Z w +f 14 , z c v c =f 21 X w +f 22 Y w +f 23 Z w +f 24 , z c =f 31 X w +f 32 Y w +f 33 Z w +f 34 , Eliminate the linear relationship coefficient z from high dimension to low dimension c Then we get: f 11 X w +f 12 Y w +f 13 Z w +f 14 -f 31 X w u c -f 32 Y w u c -f 33 Z w u c -f 34 u c =0, f 21 X w +f 22 Y w +f 23 Z w +f 24 -f 31 X w v c -f 32 Y w v c -f 33 Z w v c -f 34 v c =0, Assume [u c v c ]There are N groups of matching points [u c1 v c1 ] to [u cN v cN ],[X w Y w Z w ]There are N sets of matching points [X w1 Y w1 Z w1 ] to [X wN Y wN Z wN ],get: Solved and make Combining F = [KR Kt], we get the rotation parameter matrix R and translation parameter matrix t as:

4. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 3, characterized in that: Solved and The methods include: If N = 6, directly solve the linear equations; If N>6: set up: Then AF=0; Calculate the least squares solution under the constraint of |F|=1, and then decompose A using the SVD method: A=UDV T , Where A is a 2N×12 matrix, U is a 2N×2N matrix after decomposition, D is a 2N×12 matrix after decomposition, and V is a 12×12 matrix after decomposition; the last column of matrix V gives and The solution.

5. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 4, characterized in that: The method to establish the real space coordinate system is: Select spatial anchor points (A, B, C, D) corresponding to the feature points in the real scene, and establish a real space coordinate system based on the spatial anchor points; In the AR device coordinate system, the three inconsistency anchor point vectors corresponding to the spatial anchor points (A, B, C, D) are: Where (a1, b1, c1) is the corresponding difference between the coordinate values ​​of spatial anchor point B and spatial anchor point A in the AR device coordinate system; (a2, b2, c2) is the corresponding difference between the coordinate values ​​of spatial anchor point C and spatial anchor point A in the AR device coordinate system; (a3, b3, c3) is the corresponding difference between the coordinate values ​​of spatial anchor point D and spatial anchor point A in the AR device coordinate system; The Schmidt orthogonalization algorithm is used to orthogonally normalize the three inequitable surface anchor point vectors: Take r = 3, in: J1=a1 2 +b1 2 +c1 2 , <h2 style=";text-align:left;direction:ltr">J2=a2<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +b2<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +c2<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> , H1=a1a2+b1b2+c1c2, H2=a1a3+b1b3+c1c3, H3=a2a3+b2b3+c2c3, standardization: In the real scene, the spatial anchor point A is used as the coordinate origin O r ,by The vector direction is X r Axis direction, The vector direction is Y r Axis direction, The vector direction is Z r Axis direction, establish the real space coordinate system (O r X r Y r Z r ).

6. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 5, characterized in that: The method for calculating the second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system is: AR device coordinate system (O c X c Y c Z c ) and the real space coordinate system (O r X r Y r Z r ) is: Where M is the second coordinate transformation matrix: The pose coordinates of the virtual model of the unfolding mechanism in the AR device coordinate system are obtained.

7. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 6, characterized in that: The method for solving the pose coordinates of the virtual model of the unfolding mechanism in the AR device coordinate system is: Assume that the coordinate system of the virtual model of the unfolding mechanism is ( b X b Y b Z b ), its position coordinate in the real space coordinate system is (X r1 ,Y r1 ,Z r1 ), the position of the virtual model of the unfolding mechanism in the real space coordinate system is expressed by four infinite numbers: Solve the position coordinates (X c1 ,Y c1 ,Z c1 ): The coordinates of the body are (O b X b Y b Z b ) and the real space coordinate system (O r X r Y r Z r ) is: In the formula The coordinate transformation matrix from the real space coordinate system to the body coordinate system: Combining the second coordinate transformation matrix from the AR device coordinate system to the real space coordinate system, we can get the transformation relationship between the body coordinate system and the AR device coordinate system: In the formula To unfold the virtual model of the mechanism in the AR device coordinate system: The coordinate transformation matrix from the AR device coordinate system to the body coordinate system; The equation obtained from the above conversion relationship is: Solve and obtain the position and posture of the virtual model of the unfolding mechanism in the AR device coordinate system 8. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 7, characterized in that: According to the application scenarios, mission requirements and performance indicators of the spacecraft deployment mechanism, the design data is established and documented to obtain the data model of the entire system; Establish the data conversion relationship between the whole system data model and the virtual simulation framework, and generate the virtual simulation framework through the Solidworks module by using the 3dmax data interface to convert the whole system data model into a virtual simulation framework.

9. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 8, characterized in that: The virtual simulation framework includes a truss, a hanger, a flip beam and a cylinder; the virtual simulation framework is integrated with the real scene point cloud model to obtain a fused virtual framework; the virtual model of the unfolding mechanism includes a hinge mechanism and a fixed frame; The virtual model of the unfolding mechanism is fixed on the fused virtual frame to form a virtual simulation system.

10. The method for designing a virtual simulation system for a spacecraft deployment mechanism according to claim 9, characterized in that: After the virtual simulation system is built, a driving force is added to the hinge mechanism of the virtual model of the unfolding mechanism, and a locking mechanism is added to the predetermined unfolding position of the virtual model of the unfolding mechanism to control the virtual model of the unfolding mechanism to unfold twice under the action of the driving force, thereby realizing the performance test of the virtual model of the unfolding mechanism.

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