Skin stretch forming simulation method based on self-generated section line
By tracking the positional relationship between the clamping device connection line and the mold surface, the degree of deformation during the skin stretching process is determined, solving the problem of excessively long simulation time in the existing technology and realizing efficient calculation of skin stretching and forming simulation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI AIRCRAFT MFG
- Filing Date
- 2026-01-28
- Publication Date
- 2026-05-01
AI Technical Summary
Existing simulation methods for skin stretching and forming rely on explicit finite element analysis, which results in excessively long simulation times and makes it difficult to meet the needs of multiple iterations in the process design stage.
By tracking the positional relationship between the clamping device's connection line and the mold surface at different time steps, the target time step of the first intersection state between the clamping device's connection line and the mold is determined, and the stretching ratio is calculated based on this, simplifying it into a problem of multiple connection line deformations and avoiding complex finite element algorithm calculations.
It enables rapid prediction of skin deformation, improves computational efficiency, reduces simulation time, and increases the computational speed of the simulation process.
Smart Images
Figure CN121959950A_ABST
Abstract
Description
A simulation method for skin stretching based on self-generated cross-section lines Technical Field
[0001] This application relates to the field of skin stretching technology, and in particular to a skin stretching simulation method, apparatus, readable storage medium and electronic device. Background Technology
[0002] Existing simulation methods for skin stretching generally rely on explicit finite element analysis. While this method offers high accuracy, a single simulation takes too long, making it difficult to meet the needs of multiple iterations during the process design phase. Therefore, a more efficient and reliable alternative solution is urgently needed. Summary of the Invention
[0003] This application provides a skin stretching simulation method, apparatus, readable storage medium, and electronic device.
[0004] This application provides the following solution:
[0005] According to a first aspect, a method, apparatus, readable storage medium, and electronic device for simulating skin stretching are provided, the method comprising:
[0006] The motion trajectory of the gripper during the stretching process is obtained. Multiple grippers are set on both sides of the mold. The grippers are used to hold the skin. Each gripper on one side of the mold forms a gripper pair with each gripper on the opposite side.
[0007] Based on the position of the gripper pair on the motion trajectory at each time step during the stretching process, the target time step in which the line connecting the gripper pairs first intersects with the mold is determined, and the stretching ratio at the intersection of the line connecting the gripper pairs with the mold at the target time step is determined.
[0008] Based on the stretching factor of the intersection at the target time step, the stretching factor of the intersection at each time step after the target time step is determined sequentially, and used as the simulation result.
[0009] According to a second aspect, a skin stretching simulation device is provided, the device comprising:
[0010] The motion trajectory acquisition module is used to acquire the motion trajectory of the gripper during the stretching process. Multiple grippers are set on both sides of the mold. The grippers are used to grip the skin. Each gripper on one side of the mold forms a gripper pair with each gripper on the opposite side.
[0011] The initial stretching ratio determination module is used to determine the target time step in which the line connecting the gripper pairs and the mold first intersect, based on the position of the gripper pairs on the motion trajectory at each time step during the stretching process, and to determine the stretching ratio at the part where the line connecting the gripper pairs intersects with the mold at the target time step.
[0012] The subsequent stretching ratio determination module is used to determine the stretching ratio of the intersection portion of each time step after the target time step based on the stretching ratio of the intersection portion at the target time step, and use it as the simulation result.
[0013] According to a third aspect, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the above-described skin stretching simulation method.
[0014] According to the fourth aspect, an electronic device is provided, comprising:
[0015] One or more processors; and
[0016] A memory associated with one or more processors, the memory being used to store program instructions, which, when read and executed by one or more processors, perform the steps of the above-described skin stretching simulation method.
[0017] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described skin stretching simulation method.
[0018] According to the specific embodiments provided in this application, the following technical effects are disclosed:
[0019] This application improves computational efficiency and reduces simulation time by tracking the positional relationship between the clamping device's connection line and the mold surface at different time steps.
[0020] Of course, any product implementing this application does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description
[0021] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0022] Figure 1 is a flowchart of the skin stretching simulation method provided in the embodiment of this application.
[0023] Figure 2 is a schematic diagram of the mesh model of the imported mold.
[0024] Figure 3 is a schematic diagram of the clamp pairs into which the clamp is divided.
[0025] Figure 4 is a schematic diagram of the contact state at the target time step.
[0026] Figure 5 is a schematic diagram of the validity judgment of the edge intersection.
[0027] Figure 6 is a schematic diagram of the stretching factor of each time step after the target time step.
[0028] Figure 7 is a cloud map of the stretching ratio obtained by simulation based on the method provided in the embodiments of this application.
[0029] Figure 8 is a flowchart of a specific implementation of the skin stretching simulation method provided in this application.
[0030] Figure 9 is a schematic diagram of the skin stretching simulation method provided in the embodiments of this application.
[0031] Figure 10 is a schematic block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation
[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0033] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0034] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0035] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."
[0036] Figure 1 is a flowchart of the skin stretching simulation method provided in an embodiment of this application. As shown in Figure 1, the method may include the following steps:
[0037] Step S110: Obtain the motion trajectory of the clamp during the stretching process. Multiple clamps are set on both sides of the mold. The clamps are used to clamp the skin. Each clamp on one side of the mold forms a clamp pair with each clamp on the opposite side.
[0038] Step S120: Based on the position of the gripper pair on the motion trajectory at each time step during the stretching process, determine the target time step in which the line connecting the gripper pairs first intersects with the mold, and determine the stretching ratio at the part where the line connecting the gripper pairs intersects with the mold at the target time step.
[0039] Step S130: Based on the stretching ratio of the intersection part at the target time step, determine the stretching ratio of the intersection part of each time step after the target time step in sequence, and use it as the simulation result.
[0040] As can be seen from the above process, this application can quickly predict the degree of deformation of the skin at different time steps by tracking the positional relationship between the connection of the gripper and the mold surface at different time steps, thereby effectively improving the calculation efficiency and reducing the simulation time.
[0041] The following describes in detail each step of the above process and the effects that can be further produced, with reference to the embodiments.
[0042] First, the above step S110, namely "obtaining the motion trajectory of the clamp during the stretching process, with multiple clamps correspondingly arranged on both sides of the mold, the clamps being used to clamp the skin, and each clamp on one side of the mold forming a clamp pair with each clamp on the opposite side", will be described in detail with reference to the embodiment.
[0043] During simulation, the mesh model 210 of the mold can be imported, and the node numbers and corresponding coordinate information of its mesh patches can be extracted.
[0044] For example, the mesh model 210 of the mold can be as shown in Figure 2.
[0045] The gripper is used to hold the skin. The gripper can move toward the mold along a predetermined motion trajectory, thereby driving the skin to move toward the mold and finally achieving the stretching and forming of the skin.
[0046] Multiple clamps can be set on both sides of the mold to achieve clamping on opposite sides. For ease of illustration, the two sides of the mold will be referred to as the left and right sides.
[0047] For example, Figure 3 is a schematic diagram of the clamp pairs into which the clamp is divided.
[0048] As shown in Figure 3, in this example, the gripper can specifically be a clamp. The clamps on the left side can form a left clamp group 310, which may include clamps 311, 312, 313, etc. The clamps on the right side can form a right clamp group 320, which may include clamps 321, 322, 323, etc. N represents the total number of clamps on one side. A gripper pair can consist of one clamp on the left and one clamp on the right, such as the left clamp... The first clamp, the one on the right. A pair of clamps can be formed, wherein... , .
[0049] In this example, the number of grippers in the clamp assembly on one side can be set according to actual needs, such as one or more. The number of grippers in the clamp assemblies on both sides can be the same or different, and this embodiment does not limit this.
[0050] The following describes in detail step S120, namely, "based on the position of the clamp pair on the motion trajectory at each time step during the stretching process, determine the target time step in which the line connecting the clamp pairs first intersects with the mold, and determine the stretching multiple at the part where the line connecting the clamp pairs intersects with the mold at the target time step," with reference to the embodiments.
[0051] The skin stretching process can be divided into multiple time steps according to a preset time interval. Based on the movement trajectory of the gripper, the spatial position of the gripper in each time step can be extracted.
[0052] The time interval can be set according to factors such as the actual movement speed of the gripper. In this embodiment, its size is not limited. For example, it can be 0.1 seconds or 0.01 seconds.
[0053] The line connecting the grippers can be understood as the line connecting the gripping points of the two grippers in the gripper pair. The gripping point can be understood as a spatial position point obtained by abstracting the position of the gripper clamping the skin.
[0054] For example, a single gripper may correspond to one or more gripping points. For instance, multiple grippers may be included on each side of the mold, each gripper corresponding to one gripping point, with one gripper selected on each side to form a gripper pair. Alternatively, each side of the mold may contain only one gripper, which may correspond to multiple gripping points.
[0055] During the stretching process, the intersection of the skin and the mold can be referenced by the line connecting the two clamps centered on one clamp.
[0056] For any pair of grippers, the target time step is the time step when the line connecting the grippers and the mold first intersects, that is, when the skin and the mold begin to contact at the target time step.
[0057] The stretch ratio characterizes the ratio of the stretched length of a skin to its original length during the stretch forming process. The stretch ratio can quantify the degree of stretch deformation; the larger the stretch ratio, the greater the local elongation of the skin.
[0058] The part where the connecting line intersects with the mold, that is, the part of the skin covering the mold at the location of the connecting line. Calculate the stretch ratio of the part where the connecting line intersects with the mold at the target time step, which is to calculate the stretch ratio of the part of the skin covering the mold at the location of the connecting line when the skin and the mold begin to contact.
[0059] This solution can track the positional relationship between the clamping device's connection line and the mold surface based on pure geometric relationships, thereby accurately capturing the moment when the connection line and the mold make initial contact, i.e., the target time step.
[0060] The following describes in detail step S130, namely, "based on the stretching ratio of the intersection part at the target time step, determine the stretching ratio of the intersection part of each time step after the target time step in sequence, and use it as the simulation result," with reference to the embodiments.
[0061] The stretching ratio of the target time step can be used as a benchmark for the deformation trend in subsequent time steps. As the time steps progress, the subsequent stretching ratio is recursively calculated, thereby simulating the physical process of the skin gradually covering the mold under the action of the clamp.
[0062] This solution simplifies the skin stretching process, which involves multiple gripper pairs moving along complex trajectories, into an analysis of the spatial position of each independent gripper pair at different time steps. The line connecting a group of grippers represents a segment of the skin edge that is being held together, thus decomposing the complex skin deformation problem into multiple line deformation problems, thereby simplifying the problem.
[0063] For example, for the intersection of the lines connecting any two clamp pairs, based on the tensile multiple of the intersection along the two connecting lines, the complete plane stress state and thickness strain of the intersection can be derived from the strain in the two associated directions based on the plane stress assumption, the condition of constant volume of plastic deformation, and the constitutive relation of the material.
[0064] In summary, based on steps S210 to S230, this application can quickly predict the deformation degree of the skin at different time steps by tracking the positional relationship between the connection of the gripper and the mold surface at different time steps. This avoids the complex calculation process of the finite element algorithm, effectively improves the calculation efficiency, and reduces the simulation time.
[0065] In one optional embodiment of this application, the target time step in which the line connecting the gripper pairs first intersects the mold is determined based on the positions of the gripper pairs on the motion trajectory at each time step during the forming process, including:
[0066] Starting from the first time step in the forming process, based on the position of the gripper pair in the motion trajectory at each time step, it is determined whether the cross section of the line connecting the gripper pairs passes through the mold. In response to the line passing through the mold, the edge intersection points on both sides of the intersection are determined. Based on the positional relationship of the edge intersection points on both sides, the validity of the edge intersection points is determined. Until the edge intersection point of any time step is determined to be valid, it is determined that the line connecting the mold is in the first intersection state at that time step, and that time step is determined as the target time step, with the cross section perpendicular to the placement plane of the mold.
[0067] Starting from the first time step, the intersection state of the connection between the clamping pair and the mold can be determined step by step, thereby accurately capturing the target time step when the connection first intersects with the mold.
[0068] By using the cross-section that is perpendicular to the plane where the mold is placed, and determining whether the cross-section passes through the mold, complex three-dimensional deformation can be transformed into two-dimensional deformation, thus achieving geometric dimensionality reduction of the problem.
[0069] When it is determined that at a certain time step, the cross section containing the connecting line passes through the mold, it means that within that cross section, the connecting line intersects the mold surface (represented by the cross section intersection line), and there are two edge intersection points. However, not all geometric intersection points represent physically reasonable initial contact points. Therefore, a validity judgment step for edge key points is needed. Based on the positional relationship between these two edge intersection points, it is determined whether they are valid. Only when the edge intersection point at any time step is determined to be valid can it be considered that the connecting line and the mold are in a reasonable intersection state for the first time at that time step, and this time step is determined as the "target time step" to start subsequent simulations. By judging the validity of edge intersection points, the accuracy of the simulation starting point can be ensured, thereby improving simulation accuracy.
[0070] For example, Figure 4 is a schematic diagram of the contact state at the target time step.
[0071] As shown in Figure 4, the cross-section of the line connecting the left clamp 411 and the right clamp 421 at the (t-1)th time step does not pass through the mold. The cross-section of the line connecting the left clamp 412 and the right clamp 422 at the tth time step passes through the mold, resulting in multiple intersection points. These intersection points include: the left edge intersection point 431 at the tth time step, the right edge intersection point 432 at the tth time step, and multiple intermediate intersection points 430 located between the left edge intersection point 431 and the right edge intersection point 432.
[0072] In one optional embodiment of this application, determining the validity of the edge intersection points based on the positional relationship between the intersection points on both sides includes:
[0073] Construct a virtual line that passes through the intersection of a gripper and its edge on the same side, and determine the depth value of the virtual line as it extends to the location of the gripper on the opposite side.
[0074] If the depth of the virtual line extending to the opposite gripper position is not greater than the depth of the opposite gripper position, then the edge intersection is determined to be invalid.
[0075] If the depth of the virtual line extending to the opposite gripper position is greater than the depth of the opposite gripper position, then the edge intersection is determined to be valid.
[0076] This involves constructing a virtual line that passes through the gripper (e.g., the left gripper) and intersects with its edge on the same side (e.g., the left edge intersection). This virtual line is then extended along its direction to the location of the opposite gripper (e.g., the right gripper). A "depth value" is calculated and determined in the vertical direction of this extension (typically the Z-axis, i.e., the depth coordinate). This depth value represents the theoretical depth that could be achieved at the opposite gripper (right side) location if the skin were strictly wrapped within this section according to the current contact direction on this side (left).
[0077] After obtaining the depth value of the virtual line at the position of the opposite gripper, it is compared with the actual depth value of the opposite gripper position. The "actual depth value" refers to the Z coordinate corresponding to the spatial position of the opposite gripper at the current time step.
[0078] If the depth value of the virtual line extension is not greater than (i.e. less than or equal to) the actual depth value of the opposite gripper, then the set of edge intersections is deemed invalid. This indicates that, based on the current contact direction on this side, the skin edge is positioned "too low" or "too far back" on the opposite side, making it impossible to form a reasonable stretching and covering relationship with the opposite gripper, potentially corresponding to a physically impossible or extremely unstable contact state.
[0079] If the depth value of the virtual line extension is greater than the actual depth value of the gripper on the opposite side, then the set of edge intersections is considered valid. This indicates that the virtual wrapping path starting from the contact direction on the current side has a "higher" or "more forward" depth on the opposite side, which is consistent with the physical process of the skin gradually wrapping from both sides to the middle and the contact points gradually rising under tension.
[0080] For example, Figure 5 is a schematic diagram of the validity judgment of edge intersections.
[0081] As shown in Figure 5, when the virtual line extending from the intersection point 520 of the left gripper 511 and the left edge reaches the intersection point of the right edge, its Z coordinate is lower than the actual Z coordinate of the right gripper 512.
[0082] In this scheme, by designing a virtual line depth comparison, a reasonable and efficient verification of the initial contact state is achieved, thereby effectively ensuring the accuracy of the simulation starting point.
[0083] For example, the validity of an edge intersection can be determined by the following formula.
[0084] (Formula 1)
[0085] Among them, the The coordinates of the left clamp point at each time step are: The coordinates of the right clamp point are The coordinates of the intersection of the left edges are Projecting the above points onto On the plane, connect the projection point of the left clamp with the projection point of the left tangent point. Find the coordinates of this line. Z-coordinate at the location .
[0086] like If the edge intersection is invalid, the process proceeds to the next time step until a valid edge intersection is found or all time steps have been traversed. If no valid edge intersection is found after traversing all time steps, the gripper pair is discarded. If a valid edge intersection is found, the process can proceed to the next step.
[0087] In one optional embodiment of this application, determining the stretching ratio at the intersection of the target time step line and the mold includes:
[0088] Determine the distance from the intersection point of the line connecting the target time step and the edges on both sides of the mold to the clamps on the same side;
[0089] Determine the length of the intersection between the mold surface and the connecting line;
[0090] Based on the distances from the intersection points of the two sides to the clamps on the same side, the length of the intersection of the connecting line and the mold, and the length of the connecting line, the stretching ratio of the part where the connecting line intersects with the mold at the target time step is determined.
[0091] In the target time step, the distance from the intersection of the line and the edges on both sides of the mold to the clamp on the same side represents the length of the free part of the skin that has not yet been attached to the mold at the initial contact moment.
[0092] The length of the intersection between the mold surface and the connecting line indicates the length of the portion of the skin that has already come into contact with the mold and begun to deform at the initial contact moment.
[0093] The initial stretch ratio can be determined by a clear mathematical relationship (usually a ratio or formula) based on the lengths of the two free segments, the length of the contact segment, and the total length of the connecting line.
[0094] For example, the stretch ratio can be calculated using the following formula two.
[0095] (Formula 2)
[0096] Among them, if the first Using the target time step as the first time step and finding valid edge intersections, the distance from the left edge intersection to the left gripper can be calculated. Distance from the intersection of the right edges to the right gripper Arrange the intersections between the two edge intersections according to... The coordinates are arranged in order of magnitude. The distances between adjacent intersection points are calculated and summed to obtain the new contact length. This refers to the contact segment length. The original length can be obtained based on the positions of the left and right grippers at the first time step. . This indicates the stretching ratio at each intersection of the connecting line and the mold.
[0097] In one optional embodiment of this application, the stretching factor of the intersection portion of each time step after the target time step is determined sequentially based on the stretching factor of the intersection portion at the target time step, including:
[0098] Starting from the first time step after the target time step, the stretching ratio of the intersecting part in the next time step is determined based on the stretching ratio of the intersecting part in the previous time step, the length between the same-side gripper and the edge intersection point in the previous time step, the length of the newly added intersecting part in the next time step, and the length between the same-side gripper and the edge intersection point in the next time step.
[0099] Among them, the stretching factor of the previous time step is a recursive historical benchmark, representing the overall degree of deformation that the skin has accumulated on the cross-sectional strip up to time step t.
[0100] The length between the intersection of the same-side clamp and the edge in the previous time step represents the length of the free segment of the skin before it comes into contact with the mold at time step t.
[0101] The length of the newly added intersection in the next time step represents the length of the material that the skin newly covers onto the mold from time step t to t+1 as the clamp moves.
[0102] The length between the intersection of the same-side gripper and the edge in the next time step represents the updated free segment length at time step t+1.
[0103] After determining the above four parameters, the tensile deformation ratio of the next time step is calculated by associating the newly added contact deformation (characterized by the length of the newly added intersecting part) with the geometric state of the current free segment and superimposing its influence on the total historical deformation.
[0104] For example, the stretch ratio can be calculated using the following formula three.
[0105] (Formula 3)
[0106] Among these, the stretching ratio at each time step after the target time step can be analyzed independently for the deformation of the left and right sides. Taking the right side as an example, the stretching ratio at each time step can be obtained... The distance from the intersection of the right edge at each time step to the right gripper Calculate the first... The distance from the intersection of the right edge at each time step to the right gripper The first The newly added intersection points at each time step are... The coordinates are arranged in order of magnitude. The distances between adjacent intersection points are calculated and summed to obtain the length of the newly added contact intersection. . For the first The pulling multiple of each time step, For the first The pull-out multiple of each time step.
[0107] For example, Figure 6 is a schematic diagram of the stretching factor of each time step after the target time step.
[0108] As shown in Figure 6, the left clamp 610 and the right clamp 621 are in the... The intersection of the line connecting time step 630 with the mold, the first time step The intersection point 641 of the right edge at time step 622. The left clamp and the right clamp 622 at the time step 641. The intersection of line 631 at +1 time step with the mold adds multiple intermediate intersection points 640 and right edge intersection point 642. This can be achieved in the... Based on the multiple of the pull shape at the nth time step, recursion is performed to obtain the nth time step. The pull ratio of the newly added intersection points at each time step.
[0109] In this scheme, for each consecutive time step, the tensile multiple of the next time step (t+1) is not solved from scratch through complex global mechanical calculations. Instead, based on the calculated results of the previous time step (t), only the geometric changes that occur in the incremental step from t to t+1 are considered, and local corrections and accumulations are performed to achieve efficient iterative calculations and improve computational efficiency.
[0110] For example, Figure 7 is a cloud map of the stretching ratio obtained by simulation based on the method provided in the embodiments of this application.
[0111] In one alternative embodiment of this application, when determining the edge intersection point of the next time step, the above method further includes:
[0112] The two edge points of the intersection between the cross section where the same-side clamp and the edge point intersect in the previous time step and the mold are determined as the edge intersection points in the next time step, and the cross section is perpendicular to the placement plane of the mold.
[0113] In the continuous forming process of skin stretching, the contact boundary between the skin and the mold gradually and continuously advances forward. Within a very short time step (Δt), due to the movement of the clamp, the contact boundary will move forward a small distance, which makes the cross-section of the previous time step intersect with the cross-section in the next time step at an effective edge intersection point.
[0114] In this scheme, the edge intersection points in each subsequent time step are determined quickly and continuously by adopting a recursive mechanism, which helps to improve computational efficiency.
[0115] For example, Figure 8 is a flowchart of a specific implementation of the skin stretching simulation method provided in the embodiments of this application.
[0116] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.
[0117] According to another embodiment, a skin stretching simulation device is provided. FIG9 shows a schematic block diagram of the skin stretching simulation device according to one embodiment. As shown in FIG9, the skin stretching simulation device 900 includes:
[0118] The motion trajectory acquisition module 910 is used to acquire the motion trajectory of the gripper during the stretching process. Multiple grippers are correspondingly arranged on both sides of the mold. The grippers are used to grip the skin. Each gripper on one side of the mold forms a gripper pair with each gripper on the opposite side.
[0119] The initial stretching ratio determination module 920 is used to determine the target time step in which the line connecting the gripper pairs and the mold first intersect, based on the position of the gripper pairs on the motion trajectory at each time step during the stretching process, and to determine the stretching ratio at the part where the line connecting the gripper pairs intersects with the mold at the target time step.
[0120] The subsequent stretching ratio determination module 930 is used to determine the stretching ratio of the intersection part of each time step after the target time step based on the stretching ratio of the intersection part at the target time step, and use it as the simulation result.
[0121] As an optional approach, the initial stretching ratio determination module 920, based on the positions of the gripper pairs on the motion trajectory at each time step during the stretching process, determines the target time step in which the line connecting the gripper pairs first intersects with the mold. Specifically, this is used for:
[0122] Starting from the first time step in the forming process, based on the position of the gripper pair in the motion trajectory at each time step, it is determined whether the cross section of the line connecting the gripper pairs passes through the mold. In response to the line passing through the mold, the edge intersection points on both sides of the intersection are determined. Based on the positional relationship of the edge intersection points on both sides, the validity of the edge intersection points is determined. Until the edge intersection point of any time step is determined to be valid, it is determined that the line connecting the mold is in the first intersection state at that time step, and that time step is determined as the target time step, with the cross section perpendicular to the placement plane of the mold.
[0123] As an optional approach, the initial stretching ratio determination module 920, when determining the validity of the edge intersection points based on the positional relationship between the edge intersection points on both sides, is specifically used for:
[0124] Construct a virtual line that passes through the intersection of a gripper and its edge on the same side, and determine the depth value of the virtual line as it extends to the location of the gripper on the opposite side.
[0125] If the depth of the virtual line extending to the opposite gripper position is not greater than the depth of the opposite gripper position, then the edge intersection is determined to be invalid.
[0126] If the depth of the virtual line extending to the opposite gripper position is greater than the depth of the opposite gripper position, then the edge intersection is determined to be valid.
[0127] As an optional method, the initial drawing ratio determination module 920, when determining the drawing ratio at the intersection of the target time step line and the die, is specifically used for:
[0128] Determine the distance from the intersection point of the line connecting the target time step and the edges on both sides of the mold to the clamps on the same side;
[0129] Determine the length of the intersection between the mold surface and the connecting line;
[0130] Based on the distances from the intersection points of the two sides to the clamps on the same side, the length of the intersection of the connecting line and the mold, and the length of the connecting line, the stretching ratio of the part where the connecting line intersects with the mold at the target time step is determined.
[0131] As an optional approach, when the subsequent stretching ratio determination module 930 determines the stretching ratio of the intersection portion of each time step after the target time step based on the stretching ratio of the intersection portion at the target time step, it is specifically used for:
[0132] Starting from the first time step after the target time step, the stretching ratio of the intersecting part in the next time step is determined based on the stretching ratio of the intersecting part in the previous time step, the length between the same-side gripper and the edge intersection point in the previous time step, the length of the newly added intersecting part in the next time step, and the length between the same-side gripper and the edge intersection point in the next time step.
[0133] As an optional method, the subsequent stretching ratio determination module 930 is also used for:
[0134] The two edge points of the intersection between the cross section where the same-side clamp and the edge point intersect in the previous time step and the mold are determined as the edge intersection points in the next time step, and the cross section is perpendicular to the placement plane of the mold.
[0135] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for system or system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and relevant parts can be referred to the descriptions in the method embodiments. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.
[0136] In addition, embodiments of this application also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of any of the methods in the foregoing method embodiments.
[0137] And an electronic device, comprising:
[0138] One or more processors; and
[0139] A memory associated with one or more processors, the memory being used to store program instructions that, when read and executed by one or more processors, perform the steps of any of the methods in the foregoing method embodiments.
[0140] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the methods in the foregoing method embodiments.
[0141] Figure 10 illustrates the architecture of the electronic device 1000, which may include a processor 1010, a video display adapter 1011, a disk drive 1012, an input / output interface 1013, a network interface 1014, and a memory 1020. The processor 1010, video display adapter 1011, disk drive 1012, input / output interface 1013, network interface 1014, and memory 1020 can communicate with each other via a communication bus 1030.
[0142] The processor 1010 can be implemented using a general-purpose CPU, microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits to execute relevant programs and implement the technical solution provided in this application.
[0143] The memory 1020 can be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 can store the operating system 1021 for controlling the operation of the electronic device 1000, and the basic input / output system (BIOS) 1022 for controlling the low-level operations of the electronic device 1000. Additionally, it can store a web browser 1023, a data storage management system 1024, and a skin-stretching simulation device 1025, etc. The aforementioned skin-stretching simulation device 1025 can be the application program that specifically implements the aforementioned steps in this embodiment. In summary, when implementing the technical solution provided in this application through software or firmware, the relevant program code is stored in the memory 1020 and executed by the processor 1010.
[0144] The input / output interface 1013 is used to connect input / output modules to realize information input and output. The input / output modules can be configured as components in output devices or externally connected to devices to provide corresponding functions. Input devices may include keyboards, mice, touch screens, microphones, various sensors, etc., while output devices may include displays, speakers, vibrators, indicator lights, etc.
[0145] The network interface 1014 is used to connect the communication module (not shown in the figure) to enable communication between this device and other devices. The communication module can communicate via wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.).
[0146] Bus 1030 includes a pathway for transmitting information between various components of the device, such as processor 1010, video display adapter 1011, disk drive 1012, input / output interface 1013, network interface 1014, and memory 1020.
[0147] It should be noted that although the above-described device only shows the processor 1010, video display adapter 1011, disk drive 1012, input / output interface 1013, network interface 1014, memory 1020, bus 1030, etc., in specific implementations, the device may also include other components necessary for normal operation. Furthermore, those skilled in the art will understand that the above-described device may only include the components necessary for implementing the solution of this application, and does not necessarily include all the components shown in the figures.
[0148] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer program product. This computer program product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.
[0149] The technical solutions provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A method for simulating skin stretching, characterized in that, include: The motion trajectory of the grippers during the stretching process is obtained. Multiple grippers are correspondingly arranged on both sides of the mold. The grippers are used to hold the skin. Each gripper on one side of the mold forms a gripper pair with each gripper on the opposite side. Based on the position of the gripper pair on the motion trajectory at each time step during the stretching process, the target time step in which the line connecting the gripper pairs first intersects the mold is determined, and the stretching ratio of the part where the line intersects the mold at the target time step is determined. Based on the stretching ratio of the part where the line intersects the mold at the target time step, the stretching ratio of the part where the line intersects the mold at each time step after the target time step is determined as the simulation result.
2. The method according to claim 1, characterized in that, The method of determining the target time step in which the line connecting the grippers and the mold first intersects the mold based on the position of the grippers pair on the motion trajectory at each time step in the forming process includes: starting from the first time step in the forming process, determining whether the cross section containing the line connecting the grippers pairs passes through the mold based on the position of the grippers pair on the motion trajectory at each time step, and determining the edge intersection points on both sides of the intersection in response to the line passing through the mold, determining the validity of the edge intersection points based on the positional relationship of the edge intersection points on both sides, until the edge intersection point of any time step is determined to be valid, then determining that the line connecting the mold first intersects the mold at that time step, and determining that time step as the target time step, wherein the cross section is perpendicular to the placement plane of the mold.
3. The method according to claim 2, characterized in that, Determining the validity of an edge intersection point based on the positional relationship between the two sides includes: constructing a virtual line passing through the edge intersection point of a gripper and its side, and determining the depth value of the virtual line extending to the opposite gripper position; in response to the virtual line extending to the opposite gripper position having a depth value not greater than the depth value of the opposite gripper position, determining the edge intersection point to be invalid; in response to the virtual line extending to the opposite gripper position having a depth value greater than the depth value of the opposite gripper position, determining the edge intersection point to be valid.
4. The method according to claim 1, characterized in that, Determining the stretching ratio of the portion where the connecting line intersects with the mold at the target time step includes: determining the lengths of the intersection points of the connecting line with the edges on both sides of the mold at the target time step from the clamps on the same side; determining the length of the portion where the mold surface intersects with the connecting line; and determining the stretching ratio of the portion where the connecting line intersects with the mold at the target time step based on the lengths of the intersection points of the edges on both sides from the clamps on the same side, the length of the portion where the connecting line intersects with the mold, and the length of the connecting line.
5. The method according to claim 1, characterized in that, The step of determining the stretching ratio of the intersecting portion in each time step after the target time step based on the stretching ratio of the intersecting portion in the target time step includes: starting from the first time step after the target time step, determining the stretching ratio of the intersecting portion in the next time step based on the stretching ratio of the intersecting portion in the previous time step, the length between the same-side gripper and the edge intersection point in the previous time step, the length of the newly added intersecting portion in the next time step, and the length between the same-side gripper and the edge intersection point in the next time step.
6. The method according to claim 5, characterized in that, Also includes: The two edge points of the section where the intersection of the same-side clamp and the edge in the previous time step intersects with the mold are determined as the edge intersection points in the next time step. The section is perpendicular to the placement plane of the mold.
7. A skin stretching simulation device, characterized in that, include: The motion trajectory acquisition module is used to acquire the motion trajectory of the grippers during the stretching process. Multiple grippers are correspondingly arranged on both sides of the mold. The grippers are used to clamp the skin, and each gripper on one side of the mold forms a gripper pair with each gripper on the opposite side. The initial stretching ratio determination module is used to determine the target time step in which the line connecting the gripper pairs first intersects the mold, based on the position of the gripper pairs on the motion trajectory at each time step during the stretching process, and to determine the stretching ratio of the portion where the line intersects the mold at the target time step. The subsequent stretching ratio determination module is used to determine the stretching ratio of the intersecting portion at each time step after the target time step, based on the stretching ratio of the intersecting portion at the target time step, as the simulation result.
8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the steps of the method described in any one of claims 1-6.
9. An electronic device, characterized in that, include: One or more processors; and a memory associated with the one or more processors, the memory being used to store program instructions that, when read and executed by the one or more processors, perform the steps of the method according to any one of claims 1-6.
10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method described in any one of claims 1-6.