Miura origami structure parametric modeling method

Abstract

The invention discloses a Miura origami structure parameterization modeling method. The method comprises the following steps that firstly, scale parameters and geometric parameters of a Miura origami structure are set; calculating position coordinates of each thin plate in the paper folding structure based on the parameters, and realizing automatic processing through Python programming; and generating a RecurDyn-Template table file containing vertex coordinates and connection relationships of all the thin plates, and importing the table into multi-body system dynamics RecurDyn software, so that a Miura origami structure model corresponding to parameter configuration is automatically established. According to the method, efficient parameterized automatic modeling of the Miura origami structure is achieved, and the method has the advantages of being easy and convenient to operate, high in repeatability and suitable for multi-scale design.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of origami engineering and computer-aided design, and particularly relates to a Miura origami structure parameterized automatic modeling method based on a dynamics simulation software RecurDyn. BACKGROUND

[0002] The origami structure, in particular the Miura origami, has great application potential in the fields of spacecraft deployable structures (such as solar panels and antennas), medical stents, flexible robots and metamaterials due to its excellent characteristics such as negative Poisson's ratio and large folding ratio.

[0003] At present, the research and analysis of the Miura origami structure seriously depend on three-dimensional modeling software (such as SolidWorks, CATIA, etc.). The traditional modeling method is inefficient and the repetitive work is heavy, and the core pain point is that it is difficult to realize fast modeling and fast modification: for Miura origami structures with different geometric parameters (such as angles and side lengths) or scale parameters (such as the number of units), researchers need to manually generate, stretch and assemble each unit structure one by one in the CAD software; once the core parameters such as the size of the structure and the number of units are adjusted, the original model is almost completely invalid, and needs to be pushed down and manually redrawn, which not only prolongs the design iteration cycle, but also introduces errors due to human operation. At the same time, the traditional modeling method has low parameterization degree, and it is difficult to realize multi-scale design and automatically generate new three-dimensional models by simply modifying the core parameters, which seriously restricts the efficiency of multi-scale optimization design in different application scenarios.

[0004] In addition, in the traditional dynamics software analysis process, the structure modeling and analysis process is fragmented. The geometric model established in the CAD software usually needs to go through additional and tedious steps (such as format conversion, model simplification, and constraint redefinition) before being imported into multi-body dynamics or finite element analysis software such as RecurDyn, Adams, etc. for simulation. This process not only consumes time, but also may cause information loss or errors, causing a breakpoint in the integrated process of "design-modeling-simulation".

[0005] Therefore, there is an urgent need for a method that can realize fast, automatic and accurate parameterization modeling of Miura origami structure and can be seamlessly integrated with mainstream simulation software. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and provide a Miura origami structure parameterized modeling method, which realizes an integrated process from parameter input to automatic generation of a three-dimensional model, effectively solving the problems of low efficiency, difficulty in ensuring accuracy and poor integration with dynamics analysis software in manual modeling.

[0007] The technical scheme for achieving the object of the present application is as follows: a Miura origami structure parameterized modeling method, comprising the following steps:

[0008] Step S1: setting scale parameters and geometric parameters of the Miura origami structure;

[0009] Step S2: based on the scale parameters and the geometric parameters, automatically generating two-dimensional plane coordinates of four vertices of all thin plates in the structure through a calculation processing unit;

[0010] Step S3: automatically generating a RecurDyn-Template table file containing all thin plate vertex coordinates and connection relationships according to the calculated two-dimensional plane coordinate data;

[0011] Step S4: importing the RecurDyn-Template table file into a RecurDyn multi-body dynamics simulation environment to automatically generate a three-dimensional model of the Miura origami structure corresponding to the scale parameters and the geometric parameters.

[0012] Further, in step S1:

[0013] The scale parameters include: the number of longitudinal Miura single plates , the number of transverse Miura single plates ;

[0014] The geometric parameters include: the length of the transverse Miura single plate , the length of the longitudinal Miura single plate , the thickness of the Miura single plate , the Miura angle , and the distance between adjacent Miura single plates ;

[0015] Wherein, the longitudinal direction refers to the arrangement direction of the Miura single plates, the transverse direction refers to the arrangement direction of the Miura single plates, and the transverse direction and the longitudinal direction are perpendicular to each other.

[0016] Further, in step S2, the calculation processing unit is implemented through a Python script program, and the Python script program performs the following processes:

[0017] (a) defining the four vertex coordinate numbers of each thin plate: the vertex number of the left upper corner of a single thin plate is a, and the numbers are b, d, and c in clockwise order, wherein the coordinates of the vertices along the transverse direction are called transverse coordinates, and the coordinates of the vertices along the longitudinal direction are called longitudinal coordinates;

[0018] (b) according to the scale parameters ( , generating an index representing the position of each panel of the Miura origami structure , wherein is the position of the longitudinal direction of the single panel, is the position of the transverse direction of the single panel;

[0019] (c) according to the geometric parameters , , , , ) and each panel index , , the two-dimensional plane coordinates of the four vertices of each panel are sequentially determined by a loop iteration algorithm based on the geometric configuration of the Miura origami.

[0020] Further, in step S2, the Python script program calculates the two-dimensional plane coordinates of the four vertices of each panel based on the following rules;

[0021] (I) the transverse coordinates of the four vertices of each panel

[0022] (I) when is odd, let the transverse coordinates of the four vertices of the panel be , , , , then

[0023] (a) when :

[0024] , , ,

[0025] (b) when :

[0026] , ,

[0027] ,

[0028] (c) when is between 1 and N:

[0029] , , unchanged, wherein

[0030] (II) when When even, let the transverse coordinates of the four vertices of the thin plate be respectively , , , At this time, we have:

[0031] (a) When ,

[0032] , , ,

[0033] (b) When ,

[0034] , ,

[0035] ,

[0036] (c) When is between 1 and N:

[0037] , , No change, where

[0038] (II) The longitudinal coordinates of the four vertices of each thin plate

[0039] The longitudinal coordinates are independent of the parity of , and the longitudinal coordinates of vertices a and b are equal, denoted as ; the longitudinal coordinates of vertices c and d are equal, denoted as At this time, we have:

[0040]

[0041] .

[0042] Further, the Python script program uses the Tkinter library to provide a graphical user interface for interactive input of the scale parameters and geometric parameters.

[0043] Further, the RecurDyn-Template table file is generated by the openpyxl library of Python, and the specific table header in the RecurDyn-Template table file corresponds to a specific modeling operation in the RecurDyn software.

[0044] Further, the specific table header in the RecurDyn-Template table file includes:

[0045] Header_PV, used for setting the parameter variable of the RecurDyn environment;

[0046] Header_PP, used for defining the point position coordinates of four vertices of each sheet;

[0047] Header_Body_New, used for triggering the operation of creating a new rigid body;

[0048] Header_Geo_Outline, used for indicating that the four vertices are sequentially connected to generate a closed outline;

[0049] Header_Geo_Sheet, used for indicating that the closed outline is filled to generate a sheet;

[0050] Header_Geo_SolidExtrude, used for indicating that the sheet is stretched along the normal direction by a specified sheet thickness distance, and finally a three-dimensional solid sheet is generated.

[0051] Further, the data organization mode in the RecurDyn-Template table file is that the modeling operation of a single sheet is taken as a basic loop unit, and for a Miura origami structure with a size of MxN, the Python script automatically generates a data block of MxN basic loop units.

[0052] Further, in the step S4, the RecurDyn software sequentially reads and executes all data blocks in the RecurDyn-Template table file, and automatically constructs a complete Miura origami structure three-dimensional model in a loop.

[0053] A Miura origami structure parameterized modeling system implements the Miura origami structure parameterized modeling method, realizes the parameterized modeling of the Miura origami structure, and executes steps S1 to S4 in four modules.

[0054] Compared with the prior art, the present application has the following advantages:

[0055] (1) The whole automation of coordinate calculation and file generation is realized through the Python script, the manual modeling time of several hours or even several days is shortened to several minutes, and the design efficiency and iteration speed are greatly improved.

[0056] (2) Based on strict geometric algorithm to calculate vertex coordinates, completely avoid the operation error in the process of artificial modeling, ensure the high precision of the model and the consistency between different design versions.

[0057] (3) The generated RecurDyn-Template table file can be directly read by RecurDyn and automatically execute the modeling command, the generated model naturally contains correct geometric information, can be directly used for subsequent rigid-flexible coupling dynamics analysis, realizes the seamless connection from design to simulation.

[0058] (4) By modifying the scale parameters (M, N), it is easy to generate Miura origami structures of different scales, which can adapt to a wide range of scientific research and engineering application requirements. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 It is the flow chart of the Miura origami structure parameterized modeling method of the application. Figure 2 It is a schematic diagram of geometric parameters and scale parameters of Miura origami structure. Figure 3 It is the APP visual interface initialization diagram in the embodiment of the application.

[0060] Figure 4 It is a schematic diagram of the data structure of the RecurDyn-Template table file generated by the Python script in the embodiment of the application.

[0061] Figure 5 It is a three-dimensional Miura origami structure model effect diagram automatically generated in the RecurDyn software in the embodiment of the application. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical scheme and advantages of the application more clear, the application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the application, and are not used to limit the application. As Figure 1 As shown in a Miura origami structure parameterized modeling method, comprising the following main steps:

[0063] Step S1: Set the scale parameters and geometric parameters of the Miura origami structure;

[0064] In the step S1, the user runs the graphical user interface (GUI) application developed by the Tkinter library of Python, and the interface is initialized as Figure 3 As shown in the figure. In the corresponding input box of the interface, the specific values of the above-mentioned geometric parameters and scale parameters are input in turn, wherein:

[0065] Scale parameters include: number of vertical Miura veneers Horizontal Miura single-layer board quantity ;

[0066] Geometric parameters include: transverse Miura veneer length Longitudinal Miura veneer length Miura veneer thickness Miura's angle Spacing between adjacent Miura panels ;

[0067] Wherein, the longitudinal direction refers to the The arrangement direction of the Miura veneers, horizontally refers to the... The Miura veneers are arranged in a direction that is perpendicular to each other in the horizontal and vertical directions.

[0068] Step S2: Based on the scale parameters and geometric parameters, the two-dimensional plane coordinates of the four vertices of all thin plates in the structure are automatically calculated by the calculation processing unit;

[0069] In step S2, after the user clicks the "Calculate" button, the Python script program begins to execute the core calculation task.

[0070] 1. Generate Unit Index: The script first generates an index representing the position of each sheet in the Miura origami structure based on the scale parameters (M, N). , ),in The longitudinal position of a single thin plate. This represents the lateral position of a single sheet; this index corresponds one-to-one with all the sheets in the Miura structure.

[0071] 2. Define vertex numbering rules: As described in claim 3, define four vertices for each quadrilateral thin plate. Taking the plane where the thin plate is located as a reference, set the top left vertex as a, and the others as b, d, and c in a clockwise direction. The coordinates of the vertex along the horizontal direction are called the horizontal coordinates, and the coordinates along the vertical direction are called the vertical coordinates.

[0072] 3. Calculate spatial coordinates: The script is based on the geometric principles of Miura origami structures, and uses a loop iterative algorithm to calculate the coordinates for indices ( ). , Calculate the coordinates of the four vertices of the thin plate. Based on the geometric parameters ( , , , , ) and the index of each unit ( , ), based on the geometric configuration principle of Miura origami, the two-dimensional plane coordinates of the four vertices of each sheet are determined in turn by a cyclic iteration algorithm, which can be expressed as: (here the and represent the position of the sheet, where , represents the distance between the two sheets in the transverse direction, as shown in Figure 2 .

[0073] (I) The transverse coordinates of the four vertices of each sheet are:

[0074] (I) When is odd, let the transverse coordinates of the four vertices of the sheet be , , , , then:

[0075] (a) When :

[0076] , , ,

[0077] (b) When :

[0078] , ,

[0079] ,

[0080] (c) When is between 1 and N:

[0081] , , No change, where

[0082] (II) When is even, let the transverse coordinates of the four vertices of the sheet be , , , , then:

[0083] (a) When :

[0084] , , ,

[0085] (b) when ,

[0086] , ,

[0087] ,

[0088] (c) when between 1 and N:

[0089] , , unchanged, where

[0090] (ii) the longitudinal coordinates of the four vertices of each sheet are:

[0091] The longitudinal coordinates are independent of the parity of , and the longitudinal coordinates of vertices a and b are equal, denoted as ; the longitudinal coordinates of vertices c and d are equal, denoted as , so we have:

[0092]

[0093]

[0094] Step S3: According to the calculated position coordinate data, automatically generate a RecurDyn-Template table file containing all sheet vertex coordinates and connection relationships;

[0095] The step S3, the Python script calls the openpyxl library to write data into a structured RecurDyn-Template template file. The data structure diagram of the template is as shown in Figure 4 .

[0096] The template defines a specific header (Header) to indicate the corresponding modeling operation of RecurDyn.

[0097] For the first sheet (Sheet1) , , the script creates a data block in RecurDyn-Template:

[0098] (a) In the column corresponding to Header_PP (Point Position), fill in the horizontal coordinates and longitudinal coordinates of the four vertices a, b, c, d of the sheet in turn.

[0099] (b) In the line of Header_Body_New, mark "Create" to trigger RecurDyn to create a new rigid body (Body).

[0100] (c) In the line of Header_Geo_Outline, mark "Yes" to instruct RecurDyn to connect the four points in order to generate a closed outline (Outline).

[0101] (d) In the line of Header_Geo_Sheet, mark "Yes" to instruct RecurDyn to fill the outline to generate a planar sheet (Sheet).

[0102] (e) In the line of Header_Geo_SolidExtrude, fill in the sheet thickness value "0.01" to instruct RecurDyn to stretch the planar sheet along the normal direction by this thickness to generate a 3D solid sheet (Solid).

[0103] The above process constitutes a basic cycle unit of sheet modeling. The script then automatically and cyclically executes this process to generate data blocks of the same structure for the rest of the sheets. Each data block contains vertex coordinates that are calculated based on its cell index (i, j). , Finally, the RecurDyn-Template table file contains all the data blocks arranged in sequence. With the modeling operation of a single sheet as a basic cycle unit, the Python script automatically generates M x N data blocks of the basic cycle unit for a Miura origami structure of M x N size.

[0104] Step S4: Import the structured data file into the RecurDyn multi-body dynamics simulation environment to automatically generate a 3D model of the Miura origami structure corresponding to the parameters.

[0105] In the step S4, the user starts the RecurDyn multi-body dynamics simulation software and reads the RecurDyn-Template template file of a specific format generated by the method through the Template function in RecurDyn.

[0106] After the cyclic processing of all data blocks, RecurDyn can automatically and quickly construct a complete M x N cell Miura origami structure 3D model in its modeling environment, as shown in Figure 5 All the sheets of the model are correctly created and positioned, and the model can be directly used to add hinge constraints, apply loads, and perform rigid-flexible coupled dynamics simulation analysis. ​

[0107] Example

[0108] This example demonstrates the construction of a medium-sized Miura origami structure, with the following specific parameters:

[0109] Step S1, set the scale and geometric parameters of the Miura origami structure as follows:

[0110] Scale parameter: Number of vertical Miura boards Horizontal Miura single-layer board quantity .

[0111] Horizontal Miura veneer length Longitudinal Miura veneer length Miura veneer thickness Miura's angle Spacing between adjacent Miura panels .

[0112] Step S2, after running the Python script, the script first determines the scale parameter. , Generate the corresponding cell index sequence ( , This index corresponds one-to-one with the 15 thin plates in the Miura structure. Subsequently, based on the geometric configuration principle of the Miura origami structure, a cyclic iterative algorithm is used to calculate the horizontal and vertical coordinates of the four vertices of each thin plate.

[0113] Step S3: The Python script calls the openpyxl library to write the calculated data, which includes the coordinates of the thin plate vertices and their connection relationships, into a structured RecurDyn-Template table file.

[0114] Step S4: Start the RecurDyn multibody dynamics simulation software, read the RecurDyn-Template table file generated by this method, and after iterative processing of all data blocks in the file, RecurDyn can automatically and quickly build a complete 5×3 unit Miura origami structure 3D model in its modeling environment.

[0115] This invention also proposes a parametric modeling system for Miura origami structures, which implements the parametric modeling method for Miura origami structures to achieve parametric modeling of Miura origami structures. The system is divided into four modules that execute steps S1 to S4 respectively.

[0116] Any technical features in the above embodiments can be combined, and for the sake of brevity, not all possible combinations are described above, however, any combination of these technical features is considered to be within the scope of the present disclosure.

[0117] The above embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but should not be understood as a limitation on the scope of the present application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for parametric modeling of Miura origami structure, characterized in that, The method comprises the following steps: Step S1: setting scale parameters and geometric parameters of the Miura origami structure; Step S2: automatically generating two-dimensional plane coordinates of four vertices of all thin plates in the structure by a calculation processing unit based on the scale parameters and the geometric parameters; Step S3: automatically generating a RecurDyn-Template table file containing all vertex coordinates and connection relationships of the thin plates according to the calculated two-dimensional plane coordinate data; Step S4: importing the RecurDyn-Template table file into a RecurDyn multi-body dynamics simulation environment to automatically generate a three-dimensional model of the Miura origami structure corresponding to the scale parameters and the geometric parameters.

2. The Miura origami structure parameterized modeling method according to claim 1, wherein, In step S1: Scale parameters include: number of longitudinal Miura boards number of transverse Miura boards ; Geometric parameters include: transverse Miura strip length , longitudinal Miura strip length , Miura strip thickness , Miura angle , and adjacent Miura strip spacing ; Wherein, the longitudinal direction refers to the arrangement direction of the Miura veneer, the transverse direction refers to the arrangement direction of the Miura veneer, and the transverse direction and the longitudinal direction are perpendicular to each other.

3. The Miura origami structure parameterized modeling method according to claim 1, wherein, In step S2, the calculation processing unit is implemented by a Python script program, and the Python script program performs the following processes: (a) defining the coordinate numbers of four vertices of each thin plate: the vertex number of the upper left corner of a single thin plate is a, and the numbers are b, d, and c in clockwise order, wherein the coordinate along the horizontal direction is referred to as the horizontal coordinate, and the coordinate along the vertical direction is referred to as the vertical coordinate; (b) Based on the scale parameter ( , Generate an index representing the position of each sheet in the Miura origami structure. , ),in The longitudinal position of a single thin plate. The lateral position of a single thin plate; (c) Based on geometric parameters ( , , , , ) and each thin plate index ( , Based on the geometric configuration of Miura origami, the two-dimensional plane coordinates of the four vertices of each thin plate are determined sequentially through a cyclic iterative algorithm.

4. The Miura origami structure parameterized modeling method according to claim 3, characterized in that, In step S2, the Python script program calculates the two-dimensional plane coordinates of the four vertices of each thin plate based on the following rules: (I) the horizontal coordinates of the four vertices of each thin plate (I) when Let the transverse coordinates of the four vertices of the sheet be respectively , , , , then (a) when time: ， ， ， ； (b) when : ， ； ， ； (c) when between 1 and N: , , No change, wherein ; (II) when Let the transverse coordinates of the four vertices of the sheet be respectively , , , In this case, we have: (a) when time: ， ， ， ； (b) when time: ， ， ， ； (c) when between 1 and N: , , No change, wherein ; (II) the vertical coordinates of the four vertices of each thin plate Vertical coordinates and The parity of vertices a and b is irrelevant, and their vertical coordinates are equal; let be denoted as . The vertical coordinates of vertices c and d are equal, let them be... At this point, we have: ； 。 5. The Miura origami structure parameterized modeling method according to claim 3, wherein, The Python script program uses the Tkinter library to provide a graphical user interface to interactively input the scale parameters and the geometric parameters.

6. The Miura origami structure parameterized modeling method according to claim 4, wherein, The RecurDyn-Template table file is generated by operating the openpyxl library of Python, and specific table headers in the RecurDyn-Template table file correspond to specific modeling operations in the RecurDyn software.

7. The Miura origami structure parameterized modeling method according to claim 1, wherein, The specific table headers in the RecurDyn-Template table file include: Header_PV, used to set a parameter variable (Parameter Variable) of the RecurDyn environment; Header_PP, used to define the plane position coordinates (Point Position) of the four vertices of each thin plate; Header_Body_New, used to trigger the operation of creating a new rigid body (Body); Header_Geo_Outline, used to indicate that the four vertices are sequentially connected to generate a closed contour line (Outline); Header_Geo_Sheet, used to indicate that the closed contour line is filled to generate a plane thin plate (Sheet); Header_Geo_SolidExtrude, used to indicate that the plane thin plate is stretched along the normal direction by a specified plate thickness distance to finally generate a three-dimensional solid (Solid) thin plate.

8. The Miura origami structure parameterized modeling method according to claim 1, wherein, The data in the RecurDyn-Template table file is organized in the following manner: taking the modeling operation of a single sheet as a basic cycle unit, for a Miura origami structure of M×N size, the Python script automatically generates data blocks of M×N basic cycle units.

9. The Miura origami structure parameterized modeling method according to claim 1, wherein, In the step S4, the RecurDyn software automatically constructs a complete Miura origami structure three-dimensional model by sequentially reading and executing all data blocks in the RecurDyn-Template table file.

10. A Miura origami structure parameterized modeling system, comprising: The Miura origami structure parameterized modeling method of any one of claims 1-9 is implemented to realize Miura origami structure parameterized modeling, which is executed in four modules respectively for steps S1-S4.

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