Knitted fabric modeling method and system, computer equipment and program product

Abstract

The invention relates to a knitted fabric modeling method and system, computer equipment and a program product, and the method comprises the steps: building a plied yarn section model and a plied yarn track model, carrying out the special point sampling of the knitted fabric through the plied yarn track model, then selecting a control point, and obtaining the section information of the plied yarn of the knitted fabric through the plied yarn section model; mapping the control points and the section information of the strand to a space curve expressed by a B-spline curve to obtain the control points and section information of the strand track around any curve in the space; carrying out special point sampling on the knitted fabric through a microscope, carrying out back calculation on a single coil control point of the knitted fabric by using an NURBS special point back calculation type value point method, and solving a control curve; mapping the control points and the section information of the plied yarns of the knitted fabric to a control curve; and obtaining a trajectory equation or a control point of a control curve, and combining a software section scanning entity command to complete a spatial multi-strand knitted fabric model. Therefore, the complex characteristics of the knitted fabric coil can be reflected more accurately.

Description

Technical Field

[0001] The present application relates to the field of knitting technology, and in particular to a modeling method, system, computer device and program product for knitted fabrics. Background Art

[0002] In the current knitted fabric modeling, although some progress has been made, the mainstream modeling methods still have significant limitations. The commonly adopted strategy is to simplify the yarn or ply into a single cylindrical model. This simplification facilitates calculation and design to a certain extent, but it also brings problems that cannot be ignored.

[0003] Since the surface of actual knitted fabric loops often presents complex characteristics, including rough texture, yarn twisting, and various deformations caused by the knitting process, these characteristics cannot be accurately reflected in the existing knitted fabric cylindrical model. Therefore, when using this simplified cylindrical model for modeling, the error of the simulation data will inevitably increase. This error not only affects the accuracy of the model, but also weakens the ability of the simulation results to predict the performance of actual knitted fabrics.

[0004] The limitations of this model are particularly prominent when dealing with knitted fabrics that are made by twisting multiple strands of yarn into one strand for weaving. Such knitted fabrics tend to have a stronger sense of texture and more complex thermal, mechanical and other properties. Using a cylinder model for simulation not only fails to capture these complex texture and performance characteristics, but also leads to further errors in the simulation results, thereby reducing the practicality and reliability of the simulation results.

[0005] In addition, the ability to reproduce real multi-strand weft knitted fabrics in computers is still limited. Although there have been some attempts at appearance simulation, there are still few simulation models that can be used in multiple occasions. In particular, the use of multi-strand models for finite element simulation is almost blank. This limits the precise control and optimization of knitted fabric design and production processes, and also hinders the further development of knitted fabric performance simulation technology. Summary of the invention

[0006] Based on this, it is necessary to provide a knitted fabric modeling method, system, computer equipment and program product to address the above technical issues, which can more accurately reflect the complex characteristics of knitted fabric loops.

[0007] In a first aspect, the present application provides a modeling method for a knitted fabric, the modeling method comprising:

[0008] Establishing a strand cross-section model and a strand trajectory model, and sampling special points of the knitted fabric through the strand trajectory model, and then selecting control points to obtain cross-section information of the strands of the knitted fabric through the strand cross-section model;

[0009] Mapping the control points and the cross-sectional information of the strands onto a space curve expressed by a B-spline curve to obtain the control points and cross-sectional information of the strand trajectory around any curve in space;

[0010] The special points of the knitted fabric are sampled through a microscope, and the control points of a single loop of the knitted fabric are calculated using the NURBS special point inverse value point method, and the control curve is obtained.

[0011] Mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve;

[0012] The trajectory equation or control points of the control curve are obtained, and the spatial multi-strand knitted fabric model is completed in combination with the software cross-section scanning entity command.

[0013] In one embodiment, the step of obtaining the trajectory equation or control points of the control curve and completing the spatial multi-strand knitted fabric model in combination with a software cross-section scanning entity command further includes:

[0014] Using a NURBS curve command, input the control points, or input the trajectory equation of the control curve through a preset three-dimensional modeling software;

[0015] Combine the software's cross-section scanning entity command to complete the spatial multi-strand knitted fabric model.

[0016] In one embodiment, before the step of sampling the knitted fabric at a specific point through a microscope, the method further includes: dividing the knitted fabric into multiple groups, and performing dehairing, flattening, and drying treatments on the grouped knitted fabrics;

[0017] The step of sampling the knitted fabric at a specific point by a microscope also includes:

[0018] The processed upper surface and cross section of the knitted fabric are placed under a microscope to observe the fabric structure, and special point sampling is performed under the corresponding plug-in of the microscope. The special points include: characteristic points and interweaving points of the knitted fabric.

[0019] In one embodiment, the step of using the NURBS special point back-calculation type value point method to back-calculate the control point of a single loop of the knitted fabric also includes:

[0020] The node vector of the control point is determined using the uniform parameterization method, and the node vector u k+i (i=0,1,…,n) corresponds to special points one by one, the specific formula is:

[0021]

[0022] The first control point Q1 of the control curve is located at the midpoint of the extension line between the point itself and the subsequent control points. The specific relationship is expressed as follows:

[0023]

[0024] Where: Q Y1 , Q Y2 The midpoint of the extended line is used to calculate the control point using equation (1) above, and the control curve P is obtained.

[0025] In one embodiment, the step of establishing the strand cross-section model further includes:

[0026] The cross section of each yarn is set to be the same circle, and each yarn is a cylinder;

[0027] It is established based on the number of twisted low-ply and multi-ply yarns as well as the cross-section of the yarn and the cross-section of the cylindrical structure.

[0028] In one embodiment, the control method further includes:

[0029] When completing the spatial multi-strand knitted fabric model, the influence of the twist and twist direction of the knitted fabric on the strand shape is further considered.

[0030] In one embodiment, the step of mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve further includes:

[0031] By using the strand trajectory model, n points of the knitted fabric are taken as data points on average, and there are 2i (k + 1 / n) data points in total;

[0032] Obtain the intersection of each data point and the center line of the strand, record the intersection as the actual control point, record the position coordinates and arc length information of the strand cross-section control point, and calculate the distance from each control point to the origin:

[0033]

[0034] Divide the control curve definition domain into c equal parts, find the Vth score and substitute it into the control curve, add the accumulated sum and record it as S″. When S′iS″i≥0 appears for the first time, substitute V / c into the value of the control curve to determine the mapping point position and the strand circular cross-section information.

[0035] In a second aspect, an embodiment of the present application provides a modeling system for knitted fabrics, characterized in that the modeling system comprises:

[0036] A model building module, used to build a strand cross-section model and a strand trajectory model;

[0037] A selection module, used for sampling special points of the knitted fabric through the strand trajectory model, and then selecting control points;

[0038] A first acquisition module, used for acquiring cross-sectional information of strands of the knitted fabric through a strand cross-sectional model;

[0039] A second acquisition module is used to map the control points and the cross-sectional information of the strands onto a space curve expressed by a B-spline curve, and obtain the control points and cross-sectional information of the strand trajectory around any curve in space;

[0040] A calculation module is used to sample special points of knitted fabrics through a microscope, use the NURBS special point inverse calculation type value point method to inversely calculate the control points of a single loop of the knitted fabric, and calculate the control curve;

[0041] A mapping module, used for mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve;

[0042] The model forming module is used to obtain the trajectory equation or control points of the control curve, and complete the spatial multi-strand knitted fabric model in combination with the software section scanning entity command.

[0043] In a third aspect, an embodiment of the present application provides a computer device, which includes a memory and a processor, wherein the memory stores computer-readable instructions, and the processor is used to implement the steps of the method described above when executing the computer-readable instructions.

[0044] In a fourth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a computer program, and the computer program is used to implement the method described above when executed by a computer.

[0045] The above introduces a modeling method, system, computer equipment and program product for knitted fabrics. In constructing the knitted fabric model, special attention is paid to the simulation of the arrangement of the strand cross-section. By deeply studying the arrangement law of the yarn fiber level, this law is applied to the strand cross-section, so that the strand cross-section in the model is not only closer to the real yarn in appearance, but also achieves a high degree of simulation of the yarn fiber level in the internal structure. This design not only enhances the visual realism of the model, but more importantly, it can more realistically reflect the surface characteristics of the twisted strands, such as roughness, glossiness, etc., providing more accurate data support for subsequent simulation analysis.

[0046] In addition, when applying this knitted fabric model to simulation analysis, it will neither lose authenticity due to being too simple nor be too complex to be computationally inefficient. By optimizing the algorithm and calculation process, the acceptability of the model in terms of calculation time is ensured, so that the simulation analysis can be completed within a reasonable time. More importantly, due to the high degree of restoration of the model in structure and details, the accuracy of its simulation results has been significantly improved. This means that designers and engineers can rely more on simulation results to guide design and production decisions, thereby further improving the quality and performance of knitted fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a flow chart of a knitted fabric modeling method provided in an embodiment of the present application;

[0048] Figure 2 It is a schematic diagram of the center line of the knitted fabric coil;

[0049] Figure 3 (a) and Figure 3 (b) is a schematic diagram of a multi-strand twisted coil and a knitted fabric;

[0050] Figure 4 is a flow chart of another knitted fabric modeling method provided in an embodiment of the present application;

[0051] Figure 5 (a) is a schematic diagram of the geometric structure of the double-ply yarn after two yarns are twisted;

[0052] Figure 5 (b) is a schematic diagram of two yarns unfolding in a cylindrical strand;

[0053] Figure 6 is a flow chart of another knitted fabric modeling method provided in an embodiment of the present application;

[0054] Figure 7 is a structural block diagram of a knitted fabric modeling system provided in an embodiment of the present application;

[0055] Figure 8 It is a basic structural block diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0057] Please participate Figure 1 , Figure 1 is a flow chart of a knitted fabric modeling method provided in an embodiment of the present application, such as Figure 1 As shown, the modeling method includes the following steps:

[0058] Step S1: Establish a strand cross-section model and a strand trajectory model, and perform special point sampling on the knitted fabric through the strand trajectory model, then select control points, and obtain the cross-section information of the strands of the knitted fabric through the strand cross-section model. The strand trajectory model can be specifically a cylindrical strand trajectory model.

[0059] Step S2: Mapping the control points and cross-sectional information of the strands onto a space curve expressed by a B-spline curve to obtain the strand trajectory control points and cross-sectional information around the arbitrary space curve.

[0060] Specifically, the control points and cross-section information can be mapped to an arbitrary curve in space expressed by a B-spline curve by using a control point distance equal to an arc length method.

[0061] Step S3: sampling special points of the knitted fabric through a microscope, using the NURBS special point inverse calculation method to inversely calculate the control points of a single loop of the knitted fabric, and obtain the control curve.

[0062] Step S4: Mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve.

[0063] Step S5: Obtain the trajectory equation or control points of the control curve, and complete the spatial multi-strand knitted fabric model in combination with the software cross-section scanning entity command.

[0064] Specifically, it may include using a NURBS curve command to input the control points, or inputting a trajectory equation of the control curve through a preset three-dimensional modeling software, and further combining the software section scanning entity command to complete the spatial multi-strand knitted fabric model.

[0065] Therefore, this embodiment can be applied to the weft flat material knitted fabric model. In constructing the knitted fabric model, special attention is paid to the simulation of the arrangement of the strand cross section. By deeply studying the arrangement law of the yarn fiber level, this law is applied to the strand cross section, so that the strand cross section in the model is not only closer to the real yarn in appearance, but also achieves a high degree of simulation of the yarn fiber level in the internal structure. This design not only enhances the visual realism of the model, but more importantly, it can more realistically reflect the surface characteristics of the twisted strands, such as roughness, glossiness, etc., providing more accurate data support for subsequent simulation analysis.

[0066] In addition, when applying this knitted fabric model to simulation analysis, it will neither lose authenticity due to being too simple nor be too complex to be computationally inefficient. By optimizing the algorithm and calculation process, the acceptability of the model in terms of calculation time is ensured, so that the simulation analysis can be completed within a reasonable time. More importantly, due to the high degree of restoration of the model in structure and details, the accuracy of its simulation results has been significantly improved. This means that designers and engineers can rely more on simulation results to guide design and production decisions, thereby further improving the quality and performance of knitted fabrics.

[0067] Wherein, before the step of sampling the knitted fabric at a specific point by a microscope in step S3, the method further includes: dividing the fabric into a plurality of groups, and performing a dehairing, flattening and drying process on the knitted fabric after the grouping;

[0068] Step S3 further includes placing the processed upper surface and cross section of the knitted fabric under a microscope to observe the fabric structure, and sampling special points under the corresponding plug-in of the microscope, wherein the special points include: characteristic points and interlacing points of the knitted fabric. Figure 2 As shown in the XY axis coordinate system, N0 is the starting point of the feature point, N 14 is the end point of the feature point. N0,…,N 14 is the point at the center of the knitted fabric loop, T1,…,T 13 is the intersection point, M2,…,M 12 is the characteristic segmentation point of the Peirce model line segment. The coil height and width of the same weft plane material are defined as A (mm) and B (mm) respectively. Cut the same batch of fabrics at different positions, take each type value point multiple times, and use the average type value of each position to calculate the percentage coefficients ai and bi of the coil width and height occupied by the distance of each type value point from the X-axis and Y-axis. In the YZ axis coordinate system, Z represents the parameter of the coil in the thickness direction. For the length in the Z axis direction, the average value of each measuring point is taken for calculation. As shown in Table 1, the characteristic values ​​and coefficients of the fabric sample obtained by processing are further substituted into the average coil height A and width B to complete the calculation.

[0069] Table 1 Special point processing

[0070]

[0071] Furthermore, the step of inversely calculating the control points of the knitted fabric by sampling the NURBS curve at the special points, i.e., using the NURBS special point inverse value point method in step S3 above to inversely calculate the control points of the single loop of the knitted fabric and calculate the control curve also includes:

[0072] The node vector of the control point is determined using the uniform parameterization method, and the node vector u k+i(i=0,1,…,n) corresponds to special points one by one, the specific formula is:

[0073]

[0074] The first control point Q1 of the control curve is located at the midpoint of the extension line between the point itself and the subsequent control points. The specific relationship is expressed as follows:

[0075]

[0076] Where: Q Y1 , Q Y2 The midpoint of the extended line is used to calculate the control point using equation (1) above, and the control curve P is obtained.

[0077] Furthermore, the present application also considers that twisting of knitted fabric strands improves the tensile strength, wear resistance and heat insulation of yarns. When twisting yarns, the yarn structure is mainly determined by factors such as yarn type, yarn twist, and yarn twist direction, and the cross-sectional morphology of the strands presents a certain regularity under ideal conditions, referring to the ideal stacking model in the yarn twisting and fiber arrangement. Among them, yarn and strand are the same concept at a certain level, but usually, a single yarn is composed of fiber layers, and a strand is formed by twisting a single yarn.

[0078] Figure 3 The ideal arrangement of the strands for two situations is shown. Figure 3 As shown in (a), a small number of strands are arranged to meet daily performance requirements. When the number of strands is large, the cross-sectional arrangement is as follows Figure 3 (b) For both cases, see Figure 4 The step of establishing the strand cross-section model may further include:

[0079] Step S11: setting the cross section of each yarn to be the same circle, and each yarn to be a cylinder.

[0080] And ignore the influence of yarn hairiness and the influence of single yarn twist retraction when twisting the ply yarn, and ignore the stress deformation.

[0081] Step S12: Establish according to the number of twisted low-strand yarns and the number of multi-layer strands as well as the cross-section of the yarn and the cross-section of the cylindrical structure.

[0082] The cross section of multi-layer strands takes three layers of stacking as an example, and adopts a single-core open type. The first two layers of circular cross sections are tangent to each other. From the third layer, gaps appear between the strands. The starting position of each layer is the position of the positive half axis of the X axis O i1 , the gap spacing should be smaller than the yarn diameter, then the number of roots per layer is:

[0083]

[0084] Where: ml is the number of strands in the lth layer, l≥2. α is the ray O P1 , O P2 Angle.

[0085] In the arrangement of the strand cross section, the yarn cross section in both cases 1 and 2 has the characteristic of rotating around the circumference. In case 1, the center point O1 of the starting circle is located on the positive half axis of the X-axis, and a point on the circle is located at the origin of the coordinate system. The line connecting the centers of the circles is a regular polygon. Then the coordinates of the center of any layer in case 1 and case 2 satisfy the complex expression:

[0086]

[0087] Where: i is the category number in case 1 or the i-th layer section in case 2; j is the cross-section circle in a certain category or the cross-section of a certain layer from the starting circle O1 / O i1 The strand numbers are counted counterclockwise; r i , n i Respectively represent the number of strands of type i and the radius of the yarn cross section; R is the radius coefficient, indicating the center O1 / O i1 Distance from the origin. In case 1, R = r' i ,r′ i =r1,r′2=r2,r′3=2*31 / 2 / 3r3,r′4=21 / 2r4,r′5=r5 / tan(π / 5), in case 2, R=2(j-1)r,j≥2; where N is the coefficient of the number of yarns used for twisting the ply, in case 1, N=n i , in case 2, N = ml,

[0088] Combining equations (1) and (2), the general strand cross-section parameter equation for any situation is established:

[0089]

[0090] Where: t is the angle parameter of the parametric equation, and its range is t∈[0,2π]; (x ij ,y ij ) are the coordinates of the center of the cross section of the jth strand in the i-th type / layer arrangement.

[0091] Furthermore, when completing the spatial multi-strand knitted fabric model, the influence of the twist and twist direction of the knitted fabric on the strand shape is further considered.

[0092] The focus is on discussing the influence of twist on the strand structure and giving the limit range. Secondly, in order to truly establish the knitted fabric model, it is necessary to establish a spatial arbitrary trajectory cylindrical strand model, that is, select appropriate control points on the straight cylindrical strand, and perform projection and geometric transformation operations on the control points to obtain the spatial arbitrary strand centerline model, such as Figure 5(a) shows the geometric structure of the two-ply yarn after twisting. The angle between the apparent yarn and the ply axis, i.e. the twist angle β, is introduced as Figure 5 (b) as shown.

[0093] According to the relationship between yarn twist Tt and twist angle, the center line of the straight cylindrical strand is assumed to be the space curve expressed by parameters:

[0094]

[0095] Where: θ is the angle between the projection of the yarn around its axis on the XY plane and the X-axis (rad); u is the twist direction variable, u = ±1, when u is 1, the strand is S-twisted (clockwise), when it is -1, the strand is Z-twisted (counterclockwise).

[0096] For further information, see Figure 6 The step of "mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve" in the above step S4 further includes:

[0097] Step S21: taking n points of the knitted fabric as data points on average through the strand trajectory model, and there are 2i (k+1 / n) data points in total;

[0098] Step S22: Obtain the intersection of each data point and the center line of the strand, record the intersection as the actual control point, and record the position coordinates and arc length information of the strand cross-section control point, and calculate the distance from each control point to the origin:

[0099]

[0100] Step S23: Divide the control curve definition domain into c equal parts, find the Vth score and substitute it into the control curve, add up the sum and record it as S″, when S′ appears for the first time i -S″ i When V / c is ≥0, substitute the value of the control curve to determine the mapping point position and the strand circular cross-section information.

[0101] The present application also provides a knitted fabric modeling system, which is applied to the knitted fabric modeling method described above. Figure 7 , the system 70 comprises:

[0102] A model building module 71, used to build a strand cross-section model and a strand trajectory model;

[0103] A selection module 72, for sampling special points of the knitted fabric through the strand trajectory model, and then selecting control points;

[0104] An acquisition module 73, used for acquiring cross-sectional information of strands of the knitted fabric through a strand cross-sectional model;

[0105] A second acquisition module 74 is used to map the control points and the cross-sectional information of the strands onto a space curve expressed by a B-spline curve, and obtain the control points and cross-sectional information of the strand trajectory around any curve in space;

[0106] The calculation module 75 is used to sample special points of the knitted fabric through a microscope, use the NURBS special point inverse calculation type value point method to inversely calculate the control points of a single loop of the knitted fabric, and obtain the control curve;

[0107] A mapping module 76, for mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve;

[0108] The model forming module 77 is used to obtain the trajectory equation or control points of the control curve, and complete the spatial multi-strand knitted fabric model in combination with the software cross-section scanning entity command.

[0109] The specific construction process is as described above and will not be repeated here.

[0110] To solve the above technical problems, the present application also provides a computer device. Figure 8 , Figure 8 This is a basic structural block diagram of the computer device in this embodiment.

[0111] The computer device 6 includes a memory 61, a processor 62, and a network interface 63 that are interconnected and communicated through a system bus. It should be noted that the figure only shows a computer device 6 having components 61-63, but it should be understood that it is not required to implement all the components shown, and more or fewer components can be implemented instead. Among them, those skilled in the art can understand that the computer device here is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital processors (DSPs), embedded devices, etc.

[0112] The computer device may be a computing device such as a desktop computer, a notebook, a PDA, a cloud server, etc. The computer device may interact with a user through a keyboard, a mouse, a remote controller, a touch pad, or a voice control device.

[0113] The memory 61 includes at least one type of readable storage medium, and the readable storage medium includes flash memory, hard disk, multimedia card, card-type memory (for example, SD or DX memory, etc.), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, disk, optical disk, etc. In some embodiments, the memory 61 can be an internal storage unit of the computer device 6, such as a hard disk or memory of the computer device 6. In other embodiments, the memory 61 can also be an external storage device of the computer device 6, such as a plug-in hard disk equipped on the computer device 6, a smart memory card (Smart Med ia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Of course, the memory 61 can also include both the internal storage unit of the computer device 6 and its external storage device. In this embodiment, the memory 61 is generally used to store the operating system and various application software installed on the computer device 6, such as computer-readable instructions of the modeling method of knitted fabrics, etc. In addition, the memory 61 can also be used to temporarily store various types of data that have been output or are to be output.

[0114] The processor 62 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chips in some embodiments. The processor 62 is generally used to control the overall operation of the computer device 6. In this embodiment, the processor 62 is used to run the computer-readable instructions or process data stored in the memory 61, such as computer-readable instructions for running the modeling method of the knitted fabric.

[0115] The network interface 63 may include a wireless network interface or a wired network interface. The network interface 63 is generally used to establish a communication connection between the computer device 6 and other electronic devices.

[0116] The present application also provides another embodiment, namely, providing a computer program product, wherein the computer program product stores computer-readable instructions, and the computer-readable instructions can be executed by at least one processor to enable the at least one processor to perform the steps of the knitted fabric modeling method as described above.

[0117] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for a terminal device (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0118] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0119] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations 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 shall be subject to the attached claims.

Claims

1. A modeling method for knitted fabrics, characterized in that: The modeling method comprises: Establishing a strand cross-section model and a strand trajectory model, and sampling special points of the knitted fabric through the strand trajectory model, and then selecting control points to obtain cross-section information of the strands of the knitted fabric through the strand cross-section model; Mapping the control points and the cross-sectional information of the strands onto a space curve expressed by a B-spline curve to obtain the control points and cross-sectional information of the strand trajectory around the arbitrary space curve; The special points of the knitted fabric are sampled through a microscope, and the control points of a single loop of the knitted fabric are calculated using the NURBS special point inverse value point method, and the control curve is obtained. Mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve; The trajectory equation or control points of the control curve are obtained, and the spatial multi-strand knitted fabric model is completed in combination with the software cross-section scanning entity command.

2. The modeling method according to claim 1, characterized in that: The step of obtaining the trajectory equation or control points of the control curve and completing the spatial multi-strand knitted fabric model in combination with the software cross-section scanning entity command also includes: Using a NURBS curve command, input the control points, or input the trajectory equation of the control curve through a preset three-dimensional modeling software; Combine the software's cross-section scanning entity command to complete the spatial multi-strand knitted fabric model.

3. The modeling method according to claim 1, characterized in that: Before the step of sampling the knitted fabric at a specific point through a microscope, the method further includes: dividing the knitted fabric into a plurality of groups, and performing a dehairing, flattening and drying process on the knitted fabric after the grouping; The step of sampling the knitted fabric at a specific point by a microscope also includes: The processed upper surface and cross section of the knitted fabric are placed under a microscope to observe the fabric structure, and special point sampling is performed under the corresponding plug-in of the microscope. The special points include: characteristic points and interweaving points of the knitted fabric.

4. The modeling method according to claim 1, characterized in that: The step of using the NURBS special point back-calculation type value point method to back-calculate the control point of a single loop of the knitted fabric also includes: The node vector of the control point is determined using the uniform parameterization method, and the node vector u k+i (i=0,1,…,n) corresponds to the special points one by one, the specific formula is: The first control point Q1 of the control curve is located at the midpoint of the extension line between the point itself and the subsequent control points. The specific relationship is expressed as follows: Where: Q Y1 , Q Y2 The midpoint of the extended line is used to calculate the control point using equation (1) above, and the control curve P is obtained.

5. The modeling method according to claim 1, characterized in that: The steps of establishing the strand cross-section model also include: The cross section of each yarn is set to be the same circle, and each yarn is a cylinder; It is established based on the number of twisted low-ply and multi-ply yarns as well as the cross-section of the yarn and the cross-section of the cylindrical structure.

6. The modeling method according to claim 1, characterized in that: The control method further comprises: When completing the spatial multi-strand knitted fabric model, the influence of the twist and twist direction of the knitted fabric on the strand shape is further considered.

7. The modeling method according to claim 1, characterized in that: The step of mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve further includes: By using the strand trajectory model, n points of the knitted fabric are taken as data points on average, and there are 2i (k + 1 / n) data points in total; Obtain the intersection of each data point and the center line of the strand, record the intersection as the actual control point, record the position coordinates and arc length information of the strand cross-section control point, and calculate the distance from each control point to the origin: Divide the control curve domain into c equal parts, find the Vth score and substitute it into the control curve, add up the sum and record it as S″. When S′ appears for the first time i -S″ i When V / c is ≥0, substitute the value of the control curve to determine the mapping point position and the strand circular cross-section information.

8. A modeling system for knitted fabrics, characterized in that: The modeling system comprises: A model building module, used to build a strand cross-section model and a strand trajectory model; A selection module, used for sampling special points of the knitted fabric through the strand trajectory model, and then selecting control points; A first acquisition module, used for acquiring cross-sectional information of strands of the knitted fabric through a strand cross-sectional model; A second acquisition module is used to map the control points and the cross-sectional information of the strands onto a space curve expressed by a B-spline curve, and obtain the control points and cross-sectional information of the strand trajectory around any curve in space; A calculation module is used to sample special points of knitted fabrics through a microscope, use the NURBS special point inverse calculation type value point method to inversely calculate the control points of a single loop of the knitted fabric, and calculate the control curve; A mapping module, used for mapping the cross-sectional information of the control points and the strands of the knitted fabric onto the control curve; The model forming module is used to obtain the trajectory equation or control points of the control curve, and complete the spatial multi-strand knitted fabric model in combination with the software cross-section scanning entity command.

9. A computer device, characterized in that: The computer device comprises a memory and a processor, wherein the memory stores computer-readable instructions, and the processor is configured to implement the steps of the method according to any one of claims 1 to 7 when executing the computer-readable instructions.

10. A computer program product, characterized in that The computer program product comprises a computer program for implementing the method according to any one of claims 1 to 7 when the computer program is executed by a computer.

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