A method, system, device, and medium for dynamic deformation simulation of weft knitted fabrics

Abstract

The application discloses a weft-knitted fabric dynamic deformation simulation method, system, device and medium, and relates to the technical field of weft-knitted fabric dynamic simulation. The method comprises the following steps: establishing a weft-knitted fabric structure three-dimensional structure model comprising a plurality of loop unit three-dimensional structure models; setting an interlacing point at the mutual penetration position of the loop units to represent the position of the loop units, and setting a type value point on the center line of the loop unit describing the geometric path of the loop unit to define the shape of the loop unit; improving a traditional spring-particle model based on the interlacing point to obtain an improved spring-particle model; setting the position of the particle of the improved spring-particle model at the position of the interlacing point; simulating the center line of the loop unit by using a non-uniform rational B-spline curve, and continuously updating the particle position in the improved spring-particle model through force analysis and dynamic solving, so that the simulation process of the center line of the loop unit of the weft-knitted fabric structure is dynamically, accurately and efficiently expressed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of weft-knitted fabric dynamic simulation, in particular to a weft-knitted fabric dynamic deformation simulation method and system, an electronic device and a storage medium. BACKGROUND

[0002] Knitting computer-aided design technology originated in the 1960s, and after years of development, there are now a variety of technical solutions applied to knitted fabric simulation, but there is still a lot of room for improvement in terms of intelligence, convenience and realism, and there is a lack of dynamic effect simulation display of fabric loop deformation behavior.

[0003] In the process of development, digital and intelligent technology has played a promoting role in various industries, and computer-aided design has been increasingly applied in the knitting field to realize intelligent design and development innovation of products. Among them, weft-knitted fabric has good extensibility and elastic recovery, which leads to deformation under force, affecting the style and quality of the fabric. Therefore, studying the deformation behavior of weft-knitted fabric under force is one of the important prerequisites for designing high-quality comfortable clothing, which has a huge impact on product wearability and production quality.

[0004] Simulation of the appearance and pattern effect of weft-knitted fabric has great practical significance for guiding production, which can not only improve production efficiency but also reduce dependence on labor, and further dynamically simulate the deformation process of weft-knitted fabric composed of different basic loop units, which can further reduce production costs and improve production quality, so that the knitting industry can gain more advantages in market competition in the new era, better development, and drive the common development of related industries. SUMMARY

[0005] The purpose of the present application is to provide a weft-knitted fabric dynamic deformation simulation method, system, device and medium, which can accurately dynamically simulate weft-knitted fabric.

[0006] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0007] In a first aspect, the present application provides a weft-knitted fabric dynamic deformation simulation method, comprising:

[0008] Based on the loop unit three-dimensional structure model, a weft-knitted fabric organization three-dimensional structure model is established; wherein the weft-knitted fabric organization three-dimensional structure model comprises a plurality of loop unit three-dimensional structure models; in the loop unit three-dimensional structure model, an interlacing point is arranged at the mutual penetration of the loop units to represent the position of the loop units, and a type value point is arranged on the loop unit center line describing the geometric path of the loop unit to define the shape of the loop unit;

[0009] An improved spring-mass model is obtained by improving a traditional spring-mass model based on the interlacing points in the weft-knitted fabric structure three-dimensional model; the improved spring-mass model is a spring-mass model of the weft-knitted fabric; a basic unit of the improved spring-mass model takes a loop unit as a template, and a position of a mass point in the improved spring-mass model is set at a position of an interlacing point;

[0010] A non-uniform rational B-spline curve is adopted to simulate a center line of a loop unit, and a position of a mass point in the improved spring-mass model is continuously updated through force analysis and dynamic solving, so as to dynamically express a simulation process of the center line of the loop unit of the weft-knitted fabric structure.

[0011] Optionally, the weft-knitted fabric structure three-dimensional model is established based on the loop unit three-dimensional structure model, and specifically includes:

[0012] A loop unit three-dimensional structure model is established according to a three-dimensional geometric structure of the loop unit;

[0013] A weft-knitted fabric structure three-dimensional model is established based on the loop unit three-dimensional structure model through combination and arrangement of the loop units.

[0014] Optionally, when the loop unit is a looped loop, the looped loop has one interlacing point in each of an upper part and a lower part, and the two interlacing points on the looped loop respectively represent positions at which the looped loop and corresponding looped loops in an upper row and a lower row are mutually sleeved.

[0015] Optionally, when the loop unit is a looped loop, a basic unit of the improved spring-mass model takes the looped loop as a template, a position of a mass point is set at a position of an interlacing point, a warp spring is established between lower interlacing points of two left and right connected looped loops, and the warp spring is used to represent force between warp directions of the looped loop and a yarn warp direction; a weft spring is established between upper and lower interlacing points of the same looped loop, and the weft spring is used to represent force between weft directions of the looped loop and a yarn weft direction.

[0016] Optionally, the force borne by the mass point includes a spring force and a damping force; and the position of the mass point in the improved spring-mass model is continuously updated through force analysis and dynamic solving, and specifically includes:

[0017] State information and position information of the interlacing points in the weft-knitted fabric structure three-dimensional model are acquired;

[0018] A dynamic equation of the improved spring-mass model is solved according to the state information and the position information of the interlacing points, so as to obtain position information and state information of the mass point;

[0019] Solve a dynamic equation of the improved spring-mass model according to the position information and state information of the mass point, so as to continuously update the position of the mass point in the improved spring-mass model; the dynamic equation is constructed according to spring force and damping force.

[0020] Optionally, the dynamic equation of the improved spring-mass model is solved by using a Verlet integral method.

[0021] Optionally, the loop unit center line simulation process of the dynamic representation of the weft-knitted fabric structure specifically comprises the following steps.

[0022] According to the position information and state information of the mass point, and a first relationship function, determine the position information of the type value point on the center line of each row of loop units; the first relationship function is a relationship function between the type value point and the interlacing point according to the three-dimensional structure model of the loop unit;

[0023] Based on the inverse calculation principle of the non-uniform rational B-spline curve, according to the position information of the type value point on the center line of each row of loop units, calculate the control points of the non-uniform rational B-spline curve;

[0024] Fit the non-uniform rational B-spline curve using the control points, so as to simulate the center line of the loop unit of the weft-knitted fabric structure.

[0025] In a second aspect, the present application provides a weft-knitted fabric dynamic deformation simulation system, comprising:

[0026] A weft-knitted fabric structure three-dimensional model determination module is configured to establish a weft-knitted fabric structure three-dimensional model based on a loop unit three-dimensional structure model; wherein the weft-knitted fabric structure three-dimensional model comprises a plurality of loop unit three-dimensional structure models; in the loop unit three-dimensional structure model, an interlacing point is arranged at the mutual penetration of the loop units to represent the position of the loop units, and a type value point is arranged on the loop unit center line describing the geometric path of the loop unit to define the shape of the loop unit;

[0027] An improved spring-mass model determination module is configured to improve a traditional spring-mass model based on the interlacing points in the weft-knitted fabric structure three-dimensional model, to obtain an improved spring-mass model; the improved spring-mass model is a spring-mass model of the weft-knitted fabric; the basic unit of the improved spring-mass model is a template of the loop unit, and the position of the mass point of the improved spring-mass model is arranged at the position of the interlacing point;

[0028] A dynamic simulation module is used to simulate the center line of the loop unit by using a non-uniform rational B-spline curve, and to dynamically express the simulation process of the center line of the loop unit of the weft-knitted fabric by continuously updating the position of the particle in the improved spring-particle model through force analysis and dynamic solving.

[0029] In a third aspect, the present application provides an electronic device comprising a memory and a processor, wherein the memory is configured to store a computer program, and the processor is configured to execute the computer program to enable the electronic device to perform the weft-knitted fabric dynamic deformation simulation method of the first aspect.

[0030] In a fourth aspect, the present application provides a computer-readable storage medium storing a computer program, wherein the computer program is executed by a processor to implement the weft-knitted fabric dynamic deformation simulation method of the first aspect.

[0031] According to the embodiments of the present application, the following technical effects are achieved:

[0032] The traditional spring-particle model can describe the morphological structure of the knitted fabric to a certain extent, but has limitations in expressing the morphological details of the knitted fabric after different loop units are combined and deformed, and cannot simulate the structural morphology of the knitted fabric in detail. The present application establishes an association between the loop unit three-dimensional structure model and the improved spring-particle model based on the interlacing point, uses the non-uniform rational B-spline curve to inversely calculate the problem principle to generate the center line of the loop unit, and updates the position of the particle in the improved spring-particle system through force analysis and dynamic solving, thereby realizing the dynamic deformation simulation of the weft-knitted fabric. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0034] Figure 1 The flowchart of the weft-knitted fabric dynamic deformation simulation method provided by the embodiments of the present application is shown in the figure.

[0035] Figure 2 The loop unit three-dimensional structure model provided by the embodiments of the present application is shown in the figure. Figure 2 (a) is a left view of the loop three-dimensional structure model, Figure 2 (a) is a front view of the loop three-dimensional structure model, Figure 2 (c) is a left view of the tuck loop three-dimensional structure model. Figure 2(d) is the front view of the three-dimensional structural model of the coil;

[0036] Figure 3 This is a schematic diagram of the three-dimensional structure model of the weft-knitted fabric provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the improved spring-mass model unit corresponding to the coiled coil provided in the embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the improved spring-mass model corresponding to the coiled coil provided in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the improved spring-mass model unit corresponding to the coil provided in the embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the NURBS curve inverse calculation process provided in an embodiment of the present invention;

[0041] Figure 8 A schematic diagram of the program for simulating the dynamic deformation of weft-knitted fabrics provided in an embodiment of the present invention;

[0042] Figure 9 An illustration of a weft-knitted fabric containing multiple loops, provided in an embodiment of the present invention; Figure 9 (a) is a knitting pattern of a weft-knitted fabric containing multiple loops. Figure 9 (b) is the knitting pattern of the weft-knitted fabric after changing a looped loop to a tucked loop; Figure 9 (c) is a simulation of the dynamic changes of the weft-knitted fabric at a certain moment. Figure 9 (d) is a simulation diagram of the weft-knitted fabric in a stable equilibrium state;

[0043] Figure 10 An illustration of a weft-knitted fabric containing multiple loops, provided in an embodiment of the present invention; Figure 10 (a) is a knitting pattern of a weft-knitted fabric containing multiple loops. Figure 10 (b) is a simulation of a weft-knitted fabric containing multiple loops;

[0044] Figure 11 An illustration of a weft-knitted fabric containing multiple floats, provided as an embodiment of the present invention; Figure 11 (a) is a knitting pattern of a weft-knitted fabric containing multiple floats. Figure 11 (b) is a simulation of a weft-knitted fabric containing multiple floats;

[0045] Figure 12This is a schematic diagram of the structure of the dynamic deformation simulation system for weft-knitted fabrics provided in an embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Plain stitch (jersey stitch), also known as jersey stitch, is a basic structure in single-sided weft-knitted fabrics, consisting of continuous loop units nested in one direction.

[0049] Example 1

[0050] like Figure 1 As shown in the figure, the method for simulating the dynamic deformation of weft-knitted fabrics provided in this embodiment of the invention specifically includes:

[0051] Step 100: Based on the three-dimensional structure model of the coil unit, establish a three-dimensional structure model of the weft knitted fabric structure; wherein, the three-dimensional structure model of the weft knitted fabric structure includes several three-dimensional structure models of coil units; in the three-dimensional structure model of the coil unit, interlacing points are set at the places where the coil units interlock to represent the location of the coil units, and shape value points are set on the center line of the coil unit describing the geometric path of the coil unit to define the shape of the coil unit.

[0052] Taking a plain knit fabric composed of looped loops as an example, firstly, based on the three-dimensional geometry of the looped loops, a three-dimensional structural model of the looped loops is established, specifically as follows: Figure 2(a) and (b) of FIG. 1. For the convenience of control and description of the looped stitch, the interlacing points are set at the mutual threading positions of the looped stitches to indicate the positions of the looped stitches, and the type value points are set on the center line of the geometric path of the looped stitch to define the shape of the looped stitch. The positions of the interlacing points are indicated by the star-shaped P and the pentagon-shaped O in the figure, and each of the upper and lower parts of the looped stitch has one interlacing point, which indicates the mutual threading position of the looped stitch with the corresponding looped stitch of the upper and lower row. The positions of the type value points are indicated by the triangular points in the figure, and T0 and T8 indicate the connection positions of the looped stitch with the left and right looped stitches, i.e. the lowest positions of the sink arcs, T1 and T7 indicate the connection positions of the sink arcs with the loop columns in the looped stitch, T3 and T5 indicate the connection positions of the needle knitting arcs with the loop columns, T4 indicates the highest position of the needle knitting arc, and T2 and T6 indicate the most convex positions of the left and right loop columns.

[0053] According to the structural characteristics of other types of loop units, the three-dimensional structural model of the looped stitch can be deformed to obtain the three-dimensional structural models of various loop units. For example, the three-dimensional structural model of the tuck loop is as shown in Figure 2 (c) and (d) of FIG. 1, because the geometric structure is a hanging arc, the interlacing point in the lower half does not exist. The tuck loop has one upper interlacing point, which indicates the threading position of the tuck loop with the upper tuck loop, and the positions of the type value points are indicated by the triangular points in the figure.

[0054] In order to clearly show the three-dimensional geometric structure of the loop unit, Figure 2 the three-dimensional structural model of the looped stitch and the three-dimensional structural model of the tuck loop in FIG. 1 each include a front view and a left view, and then other views can be established according to the three-dimensional positions of the type value points in the front view and the left view.

[0055] Secondly, by the combination and arrangement of the looped stitches, the uniform and regular weft flat knitted fabric structure can be formed, the corresponding weft knitted fabric physical object is observed, measured and analyzed, and reasonable assumptions and simplifications are made, and then the three-dimensional structural model of the weft flat knitted fabric structure can be established based on the three-dimensional structural model of the looped stitch, which is specifically as shown in Figure 3 The radius of the looped stitch is r, the width of the looped stitch is D, the height of the looped stitch is H, and the thickness of the looped stitch is M. From the structural analysis and data identification in FIG. 1, Figure 3 it can be concluded that the width D of the looped stitch is embodied by 4 looped stitch diameters, i.e. 8r; the height H of the looped stitch is jointly embodied by the heights of 4r needle knitting arcs, 4r sink arcs and 7r loop columns, i.e. 15r; and the thickness M of the looped stitch is jointly embodied by 2 looped stitch diameters and an arc gap equivalent to 1 looped stitch radius, i.e. 5r.

[0056] Step 200: improving the traditional spring-mass model based on the interlacing points in the weft-knitted fabric texture three-dimensional structure model to obtain an improved spring-mass model; the improved spring-mass model is a spring-mass model of the weft-knitted fabric; a basic unit of the improved spring-mass model takes a loop unit as a template, and a position of a mass point of the improved spring-mass model is arranged at a position of an interlacing point.

[0057] The traditional spring-mass model can describe the form structure of the knitted fabric to a certain extent, but has limitations in expressing the form details of the knitted fabric after different loop units are combined together and deformed, and cannot simulate the structure form of the knitted fabric in detail.

[0058] In order to solve the limitations of the traditional spring-mass model in simulating different loop units, the spring-mass model is improved based on the interlacing points of the loop units, and the regular model is set as an adjustable model.

[0059] Taking a loop loop as an example, a loop loop corresponding improved spring-mass model unit is as shown in Figure 4 The basic unit of the improved spring-mass model takes the loop loop as a template, and the position of the mass point is arranged at the position of the interlacing point. The warp spring is established between the lower interlacing points of the two left and right connected loop loops, and is used to represent the force between the warp directions of the loop loops and the yarn warp direction. The weft spring is established between the upper and lower interlacing points of the same loop loop, and is used to represent the force between the weft directions of the loop loop and the yarn weft direction.

[0060] Due to the mutual entanglement relationship between the loop loops, in addition to the edge loop loop, the upper interlacing point P of the loop loop is located at the lower interlacing point O of another loop loop, and the two interlacing points have a position unification principle, which also determines the position of the mass point. For example: the two springs of the improved spring-mass model are essentially equivalent to the structural spring in the traditional spring-mass model; because the bending spring is not considered in the embodiment of the present application when the loop unit is bent, the bending spring is omitted in the improved spring-mass model; and because the shear spring represents the oblique force, which can be indirectly represented by the structural spring through the change of the mass point position, the shear spring is ignored in the improved spring-mass model. The improved spring-mass model corresponding to the loop loop is as shown in Figure 5

[0061] When the type of the loop unit changes, the state and position of the interlacing point also change accordingly, thereby changing the mass point and the spring. For example: the improved spring-mass model unit corresponding to the tuck loop is as shown in Figure 6 Because the geometric structure is a hanging arc, there is no lower interlacing point O ij only the upper interlacing point P ij ​Based on the direction of its yarn, it can be determined that the spring exists at the upper interlacing point P of the coil. ij and the lower interleaving point O of the left and right coils (i-1)j and O (i+1)j Between them, due to the presence of the suspension arc of the coil, the upper interleaving point P of the next coil in the same column is affected. i(j-1) It is stretched upwards. Here, ij represents the horizontal and vertical coordinates.

[0062] The basic unit of this improved spring-mass model uses a coiled coil as a template, placing the mass point at the interlacing point. However, since the lower interlacing point of the coiled coil does not exist, the weft springs connecting the lower interlacing points of adjacent coils to the lower interlacing point of the coiled coil, as well as the warp springs connecting the upper interlacing point to the lower interlacing point of the coiled coil itself, also do not exist. Therefore, a composite spring connecting the upper interlacing point of the coiled coil to the lower interlacing points of its adjacent coils to its left and right, and a warp spring connecting the upper interlacing point of the coiled coil to the upper interlacing point of its lower adjacent coil, are added. The composite spring is used to comprehensively represent the forces and yarn direction between the warp and weft directions of the coiled coil. Similarly, corresponding spring-mass model units can be established based on the geometry and yarn direction of other various deformed coils.

[0063] The size of the weft-knitted fabric is determined by initializing the radius and number of rows and columns of the coil units. The structure of the weft-knitted fabric is determined by initializing the type of each coil unit in the fabric. Based on this, the state and position of the upper and lower interlacing points of each coil unit are set. Then, taking the interlacing points as objects, the shape value point data of each coil unit in the weft-knitted fabric is obtained, thereby generating the center line of the coil unit. Spring-mass model units of various types of coil units are placed and connected to establish the spring-mass model of the weft-knitted fabric. Finally, the association between the three-dimensional structural model of the weft-knitted fabric and the spring-mass model is created.

[0064] Step 300: The center line of the coil unit is simulated using NURBS (Non-Uniform Rational B-Splines) curves, and the position of the mass point in the improved spring-mass model is continuously updated through force analysis and dynamic solution, thereby dynamically expressing the simulation process of the center line of the coil unit of the weft knitted fabric.

[0065] For a NURBS curve, a k-th degree NURBS curve can be represented as a piecewise rational polynomial vector function:

[0066]

[0067] In the formula:

[0068]

[0069] Where Ni，k (u) is the k-th normal B-spline basis function determined by the node vector U = [u0, u1, …, u n+k+1 ] and the weight factor w i is associated with the control point A i respectively. The NURBS curve can be divided into two cases in practical application: one is the direct problem, that is, the control points are given to solve the curve value points and generate the curve; the other is the inverse problem, that is, the control points are solved by the curve value points and the curve passing through the known value points is fitted.

[0070] The NURBS curve is used to simulate the center line of the coil unit, and specifically comprises the following steps:

[0071] According to the state information and position information of the interlacing point and a first relationship function, the position information of the value point on the center line of each row of coil units is determined; the first relationship function is a relationship function between the value point and the interlacing point established according to the three-dimensional structure model of the coil unit; based on the inverse problem principle of the NURBS curve, the control points of the NURBS curve are calculated according to the position information of the value point on the center line of each row of coil units; and the NURBS curve is fitted by using the control points, so as to simulate the center line of the coil unit. When a group of value points are obtained, the inverse process of the NURBS curve is as shown in Figure 7 , the column matrix and the coefficient matrix are calculated again from the calculated node vector and the boundary condition, and finally the control points are inversely calculated.

[0072] For force analysis and dynamics solving, according to the research content of the embodiment of the present application, the deformation of the weft-knitted fabric caused by the threading and pulling of each coil unit is mainly affected by the internal force, so the internal force analysis and dynamics solving of the spring-mass model on the weft-knitted fabric are carried out without considering the external force.

[0073] The internal force borne by the mass mainly includes the spring force F s and the damping force F d . The spring force can be obtained by using Hooke's law:

[0074] F s = -K s ·L (3)

[0075] In the formula, K s represents the spring coefficient; and L represents the difference between the present length of the spring and the original length of the spring, that is, the spring deformation vector. The damping force is defined as:

[0076] F d = -K d ·V (4)

[0077] In the formula, K dwhere k is the damping coefficient and V is the velocity vector of the particle.

[0078] F = F s +F d = m·a (5)

[0079] where m is the mass of the particle and a is the acceleration of the particle.

[0080] The dynamics equation of the improved spring-particle model is solved, and the commonly used methods are Euler method and Verlet integral method, wherein the Euler method includes explicit Euler method, implicit Euler method and semi-implicit Euler method. Although the Euler method is easy to implement, it also has the disadvantages of small calculation volume, large error and instability; because the Verlet integral method has great advantages in calculation time interval and calculation precision, the Verlet integral method is selected in the embodiment of the present application:

[0081]

[0082]

[0083] where X(t), V(t) and a(t) are respectively the position vector, velocity vector and acceleration vector of the particle at time t, and Δt is the time interval.

[0084] The force borne by the particle includes spring force and damping force; the position of the particle in the improved spring-particle model is constantly updated through force analysis and dynamics solving, and specifically includes:

[0085] The state information and position information of the interlacing point in the three-dimensional structure model of the weft knitted fabric are acquired; the dynamics equation of the improved spring-particle model is solved according to the state information and position information of the interlacing point, so as to obtain the position information and state information of the particle; the dynamics equation of the improved spring-particle model is solved according to the position information and state information of the particle, so as to constantly update the position information and state information of the particle in the improved spring-particle model; the dynamics equation is constructed according to the spring force and the damping force.

[0086] The loop unit center line simulation process for dynamically expressing the weft knitted fabric structure specifically includes:

[0087] According to the position information and state information of the mass points and a first relationship function, position information of the type value points on the center line of each row of the loop units is determined; the first relationship function is a relationship function between the type value points and the interlacing points according to a three-dimensional structure model of the loop units; based on a non-uniform rational B-spline curve inverse calculation principle, control points of the non-uniform rational B-spline curve are calculated according to the position information of the type value points on the center line of each row of the loop units; and the non-uniform rational B-spline curve is fitted by using the control points, so that the center line of the loop units of the weft-knitted fabric structure is simulated.

[0088] Further, the method provided by the embodiment of the present application further comprises: verifying the dynamic simulation effect of the weft-knitted fabric by using a computer program.

[0089] As shown in the program flowchart realized by a computer by using a CodeBlocks integrated development environment, a C++ language and an OpenGL function library, Figure 8 first, the related data of the three-dimensional structure model of the loop units and the traditional spring-mass point model are set by initialization, then the state and position of the interlacing points are calculated according to the data, so that the type value points are calculated and the control points are inversely calculated, then the improved spring-mass point model and the center line of the loop units are drawn, and then the force and speed of the mass points are obtained by force analysis and dynamics solving, so that the position of the mass points is constantly updated, that is, the position of the interlacing points is constantly updated, until the system tends to be in a stable state.

[0090] Figure 9 is an effect diagram of a weft-knitted fabric containing a plurality of loop stitches, wherein the knitting diagram of the weft-knitted fabric containing a plurality of loop stitches is as shown in (a) of Figure 9 If a certain loop stitch is changed into a tuck stitch, the knitting diagram of the weft-knitted fabric before force analysis and dynamics solving is as shown in (b) of Figure 9 Due to the change of the state and the movement of the position of some interlacing points and the change of the spring connection mode, the weft-knitted fabric will dynamically change and finally tend to be in a balanced stable state, wherein (c) of Figure 9 is an effect diagram of the weft-knitted fabric at a certain moment in the dynamic change process, Figure 9 and (d) of is an effect diagram of the weft-knitted fabric in the balanced stable state.

[0091] Figure 10 Figure 11 and

[0092] from Figure 9 , Figure 10 and Figure 11The analysis in the simulation diagram shows that the three-dimensional structure model of the interlacing point and the improved spring-particle model can be associated based on the interlacing point, the NURBS curve is used to simulate the coil center line, and the simulation of the coil center line is basically consistent with the geometric structure of the fabric. Through reasonable stress analysis and dynamic solving, the position of the particle in the improved spring-particle model system has a good supporting effect on the dynamic simulation process of the deformed fabric.

[0093] Other models use at least 7 points to control the modeling of a single coil. The present application uses the upper and lower interlacing points to control the coil in step 100, and uses the upper and lower interlacing points as particles in step 2200. According to the type of the coil, the mode of the intermediate connecting spring is set, the spring-particle model for the deformation of the knitted fabric is improved, the calculation amount is reduced, and the simulation efficiency is improved.

[0094] Embodiment two

[0095] In order to perform the method corresponding to the above-mentioned embodiment one, to realize the corresponding functions and technical effects, the following provides a weft-knitted fabric dynamic deformation simulation system.

[0096] As shown in Figure 12 , the system comprises:

[0097] A weft-knitted fabric organization three-dimensional structure model determination module 1 is configured to establish a weft-knitted fabric organization three-dimensional structure model based on a coil unit three-dimensional structure model. The weft-knitted fabric organization three-dimensional structure model comprises a plurality of coil unit three-dimensional structure models. In the coil unit three-dimensional structure model, an interlacing point is arranged at the mutual penetration position of the coil units to represent the position of the coil unit, and a type value point is arranged on the coil unit center line describing the geometric path of the coil unit to define the shape of the coil unit.

[0098] An improved spring-particle model determination module 2 is configured to improve a traditional spring-particle model based on the interlacing points in the weft-knitted fabric organization three-dimensional structure model, to obtain an improved spring-particle model. The improved spring-particle model is a spring-particle model for weft-knitted fabric. The basic unit of the improved spring-particle model is a coil unit template, and the position of the particle of the improved spring-particle model is arranged at the position of the interlacing point.

[0099] A dynamic simulation module 3 is configured to simulate the coil unit center line with a non-uniform rational B-spline curve, and continuously update the position of the particle in the improved spring-particle model through stress analysis and dynamic solving, so as to dynamically express the simulation process of the coil unit center line of the weft-knitted fabric organization.

[0100] Embodiment three

[0101] The electronic device provided by the embodiment of the present application comprises a memory and a processor, the memory is used for storing a computer program, and the processor runs the computer program to make the electronic device execute the dynamic deformation simulation method of the weft knitted fabric of the first embodiment.

[0102] Optionally, the electronic device can be a server.

[0103] In addition, the embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the dynamic deformation simulation method of the weft knitted fabric of the first embodiment.

[0104] In the specification, each embodiment is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts of each embodiment can be referred to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method part.

[0105] The principles and implementation manners of the present application are described by using specific examples in the present application. The above embodiment is only used to help understand the method of the present application and its core idea. Meanwhile, for the general technical personnel in the art, according to the idea of the present application, the specific implementation manner and application range can be changed. In conclusion, the content of the specification should not be understood as the limitation of the present application.

Claims

1. A method of dynamic deformation simulation of a weft-knitted fabric, characterized in that, include: Based on the three-dimensional structural model of the coil unit, a three-dimensional structural model of the weft-knitted fabric is established; wherein, the three-dimensional structural model of the weft-knitted fabric includes several three-dimensional structural models of the coil unit; in the three-dimensional structural model of the coil unit, interlacing points are set at the places where the coil units interlock to represent the location of the coil unit, and shape value points are set on the center line of the coil unit describing the geometric path of the coil unit to define the shape of the coil unit; Based on the interlacing points in the three-dimensional structural model of the weft-knitted fabric, the traditional spring-mass model is improved to obtain an improved spring-mass model; the improved spring-mass model is the spring-mass model of the weft-knitted fabric; the basic unit of the improved spring-mass model is the coil unit as the template, and the position of the mass point of the improved spring-mass model is set at the location of the interlacing point; When the coil unit is a coiled coil, there is an interlacing point at the top and bottom of the coiled coil. The two interlacing points on the coiled coil respectively indicate the positions where the coiled coil interlocks with the corresponding coiled coils in the next and next rows. When the coil unit is a looped coil, the basic unit of the improved spring-mass model uses the looped coil as a template, sets the mass position at the interlacing point, establishes a warp spring between the lower interlacing points of two left and right connected looped coils, the warp spring is used to represent the force between the looped coils in the warp direction and the warp direction of the yarn, and establishes a weft spring between the upper and lower interlacing points of the same looped coil, the weft spring is used to represent the force between the looped coils in the weft direction and the weft direction of the yarn; A non-uniform rational B-spline curve is used to simulate the center line of the coil unit. The position of the mass point in the improved spring-mass model is continuously updated through force analysis and dynamic solution, thereby dynamically expressing the simulation process of the center line of the coil unit of the weft knitted fabric.

2. A method of dynamic deformation simulation of a weft knitted fabric according to claim 1, characterized in that, The establishment of a three-dimensional structural model of weft-knitted fabric based on the three-dimensional structural model of coil units specifically includes: Based on the three-dimensional geometry of the coil unit, a three-dimensional structural model of the coil unit is established; Based on the three-dimensional structural model of the coil unit, a three-dimensional structural model of the weft-knitted fabric is established by combining and arranging the coil units.

3. A method of dynamic deformation simulation of a weft knitted fabric according to claim 1, characterized in that, The forces acting on the particle include spring force and damping force; the process of continuously updating the position of the particle in the improved spring-particle model through force analysis and dynamic solutions specifically includes: Obtain the state and position information of the interlacing points in the three-dimensional structural model of the weft-knitted fabric; Based on the state and position information of the interlacing point, the dynamic equations of the improved spring-mass model are solved to obtain the position and state information of the mass. Based on the position and state information of the particle, the dynamic equations of the improved spring-particle model are solved, thereby continuously updating the position of the particle in the improved spring-particle model; the dynamic equations are constructed based on the spring force and damping force.

4. A method of dynamic deformation simulation of a weft knitted fabric according to claim 3, characterized in that, The dynamic equations of the improved spring-mass model are solved using the Verlet integral method.

5. A method of dynamic deformation simulation of a weft knitted fabric according to claim 3, characterized in that, The simulation process of the center line of the loop unit in the dynamic expression of the weft-knitted fabric structure specifically includes: According to the position information and state information of the mass points, and a first relationship function, position information of the type value points on the center line of each row of the coil units is determined; the first relationship function is a relationship function between the type value points and the interlacing points, which is established according to the three-dimensional structure model of the coil units; Based on the non-uniform rational B-spline curve inverse calculation problem principle, the control points of the non-uniform rational B-spline curve are calculated according to the position information of the type value points on the center line of each row of the coil units; The non-uniform rational B-spline curve is fitted by using the control points, so as to simulate the center line of the coil units of the weft-knitted fabric structure.

6. A system for dynamic deformation simulation of weft knitted fabrics, characterized by, It comprises: A weft-knitted fabric structure three-dimensional structure model determination module is configured to establish a weft-knitted fabric structure three-dimensional structure model based on the three-dimensional structure model of the coil units; wherein the weft-knitted fabric structure three-dimensional structure model comprises a plurality of three-dimensional structure models of the coil units; in the three-dimensional structure model of the coil units, the interlacing points are arranged at the mutual penetration positions of the coil units to represent the positions of the coil units, and the type value points are arranged on the center line of the coil units to define the shapes of the coil units; An improved spring-mass point model determination module is configured to improve a traditional spring-mass point model based on the interlacing points in the weft-knitted fabric structure three-dimensional structure model, to obtain an improved spring-mass point model; the improved spring-mass point model is a spring-mass point model of the weft-knitted fabric; the basic unit of the improved spring-mass point model is a template of the coil unit, and the position of the mass point of the improved spring-mass point model is arranged at the position of the interlacing point; When the coil unit is a looped coil, the upper and lower parts of the looped coil each have one interlacing point, and the two interlacing points on the looped coil represent the positions of the mutual penetration of the looped coil and the corresponding looped coils of the upper and lower rows; When the coil unit is a looped coil, the basic unit of the improved spring-mass point model is a template of the looped coil, the position of the mass point is arranged at the position of the interlacing point, a warp spring is established between the lower interlacing points of the two left and right connected looped coils, and the warp spring is used to represent the force between the warp directions of the looped coils and the yarn warp direction; a weft spring is established between the upper and lower interlacing points of the same looped coil, and the weft spring is used to represent the force between the weft directions of the looped coils and the yarn weft direction; A dynamic simulation module is configured to simulate the center line of the coil units by using the non-uniform rational B-spline curve, and constantly update the positions of the mass points in the improved spring-mass point model through force analysis and dynamics solving, so as to dynamically express the simulation process of the center line of the coil units of the weft-knitted fabric structure.

7. An electronic device, comprising: It comprises a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to make the electronic device execute the weft-knitted fabric dynamic deformation simulation method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, It stores a computer program, and the computer program is executed by the processor to implement the weft-knitted fabric dynamic deformation simulation method according to any one of claims 1 to 5.

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