Method for multi-axial filament placement control of variable angle tow placement members

Abstract

The application discloses a multi-directional filament laying control method of a variable-angle filament laying component, belongs to the technical field of composite material manufacturing, and acquires filament laying design parameters and production parameters, generates a reference path curve through a path generation algorithm, and performs curvature judgment and optimization according to a curvature radius reference value, so as to ensure the path feasibility; the equal-distance, continuation and interpolation methods are adopted to generate a layer of filaments based on the production parameters, the starting point is adjusted according to a predefined laying principle, and the curve path information of the whole component is generated through filament translation; for a plurality of layers, the alternating layer principle is applied to generate the paths of the layers; control instructions containing the motion path, the filament laying angle and the speed are generated based on all the path information, so as to drive the filament laying equipment to perform the multi-directional filament laying operation; through the unit-level refined modeling and the active control of defects, the application realizes the accurate control of the variable-angle filament laying, and effectively improves the structural strength and the manufacturing quality of the composite material component.

Description

Technical Field

[0001] This invention relates to the field of composite material manufacturing technology, and in particular to a multi-directional fiber placement control method for variable angle fiber placement components. Background Technology

[0002] Fiber placement technology is one of the key processes in manufacturing advanced composite components. In traditional manufacturing, fixed-angle fiber placement is commonly used, where the fiber orientation within each layup remains constant. Existing mainstream finite element analysis software and fiber placement equipment provide mature support for this, enabling rapid model building and control command generation using "layups" as the basic unit through an intuitive interactive interface.

[0003] However, with the increasing demands for composite material components in fields such as aerospace and wind power generation, variable-angle fiber layup technology has emerged. This technology allows the fiber angle within the layup to continuously change according to design requirements, thereby enabling more precise fiber guidance in the principal stress direction and significantly optimizing the mechanical properties of the structure. However, the complexity of this technology also presents significant challenges to digital design and manufacturing.

[0004] For example, at the modeling and simulation level, existing finite element software cannot directly handle layups with continuously varying fiber angles. The software's built-in composite material modules are typically based on a fixed-angle layup assumption, making it difficult to accurately assign values ​​to the local properties of variable-angle layups. Furthermore, in actual fiber placement, due to the influence of fiber bundle width and path curvature, embedded defects (such as fiber gaps or overlaps) inevitably occur between adjacent fiber bundles. These defects significantly affect the local stiffness and strength of the component, and existing methods lack effective means to accurately characterize such defects at the element level, leading to discrepancies between simulation results and reality.

[0005] At the fiber layup control level, traditional control methods use the entire layup as the command unit, which cannot adapt to the dynamic adjustment requirements of fiber layup paths with varying angles. Especially when there are embedded defects in the component, there is a lack of control strategies that proactively integrate defect information into the fiber layup path planning, making it difficult to achieve "active avoidance" or "precise control," thus restricting the improvement of the structural strength of the final composite component. Summary of the Invention

[0006] This invention overcomes the shortcomings of the prior art and provides a multi-directional wire placement control method for variable angle wire placement components.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: a multi-directional wire placement control method for variable angle wire placement components, comprising the following steps:

[0008] S1. Obtain the filament placement design parameters, and generate a reference path curve based on the filament placement design parameters using a path generation algorithm; the filament placement design parameters include the starting point, starting angle, ending angle, path projection length, shape control parameters, and number of curve segments;

[0009] S2. Based on the physical properties of the layup fibers, determine the reference value of the radius of curvature, and judge the curvature of the reference path curve based on the reference value of the radius of curvature. If the curvature exceeds the threshold, adjust the shape control parameters to regenerate the reference path curve.

[0010] S3. Obtain production parameters, including the width of the filament bundle and the number of filament bundles in the ribbon. Based on the production parameters and the reference path curve, generate a filament laying unit composed of multiple filament bundles by means of an equidistant curve generation method, an extension curve generation method and an interpolation curve generation method.

[0011] S4. According to the predefined laying principle, adjust the starting point, and based on the adjusted starting point, generate the curve path information of the entire component plane through the ribbon translation method;

[0012] S5. For multi-layer plying, the alternating plying principle is adopted to generate the curve path information of each layer. For even-numbered layers, alternating plying is performed directly, and for odd-numbered layers, alternating plying is performed with the intermediate layer being a positive single layer.

[0013] S6. Based on the curve path information of each layer, generate a fiber placement control command and send the fiber placement control command to the fiber placement equipment to control the fiber placement head to perform multi-directional fiber placement operation according to the movement path and fiber placement angle, and dynamically adjust the fiber placement angle and path.

[0014] In a preferred embodiment of the present invention, the starting point represents the coordinates of the starting point of the filament laying path on the component plane, the starting angle represents the fiber direction angle of the filament laying path at the starting point, the ending angle represents the fiber direction angle of the filament laying path at the ending point, the path projection length represents the total length of the filament laying path on the projection plane, the shape control parameter is used to adjust the curvature change of the filament laying path, and the number of curve segments represents the number of segments of the filament laying path discretized.

[0015] In a preferred embodiment of the present invention, the path generation algorithm generates the reference path curve through a parameterized curve equation based on the starting point, starting angle, ending angle, path projection length, shape control parameters, and the number of curve segments; wherein, the parameterized curve equation is a cubic spline curve or a Bézier curve, the starting angle and ending angle are used as endpoint constraints, the shape control parameters are used as curvature adjustment factors, the path projection length is used as a limit on the total length of the curve, and the number of curve segments is used to discretize the curve into multiple line segments, each line segment corresponding to a wire-laying control point.

[0016] In a preferred embodiment of the present invention, the generation process of the filament placement unit includes: using the reference path curve as a reference, and according to the filament width and the number of filaments in the ribbon, generating multiple parallel paths using an equidistant curve generation method; wherein, the equidistant distance is calculated based on the filament width, the number of parallel paths is equal to the number of filaments in the ribbon, the extension curve generation method is used to extend the paths to the component boundary, and linear or nonlinear extension is used to ensure that the layup covers the entire plane, and the interpolation curve generation method is used to fill the gaps between the paths.

[0017] In a preferred embodiment of the present invention, the laying principle is a laying order from bottom to top and from left to right, and the adjusted starting point is determined by calculating the coordinates of the end point of the lay-up ribbon and translating it along the negative direction of the coordinate axis.

[0018] In a preferred embodiment of the present invention, the ribbon translation method includes: calculating the translation distance based on the adjusted starting point, according to the width of the ribbon bundle and the number of ribbon bundles in the ribbon, wherein the translation distance increases iteratively along the laying direction, and each translation generates a new layered ribbon until the entire component plane is covered.

[0019] In a preferred embodiment of the present invention, the fiber placement control command is based on the curve path information of each layer, extracts the path point sequence and the layup angle, and generates the motion path of the fiber placement head through a motion planning algorithm; wherein, the motion path includes straight lines and curved segments, the fiber placement angle is dynamically calculated according to the fiber direction angle at the path point, and angle smoothing processing is incorporated to ensure the continuity of fiber placement, and the fiber placement control command also includes a fiber placement speed parameter, which is dynamically adjusted according to the path curvature and the characteristics of the fiber placement material.

[0020] In a preferred embodiment of the present invention, during the generation of the filament placement unit, a defect localization algorithm is executed synchronously. The defect localization algorithm identifies potential defect areas in the layup based on the filament bundle width and the number of filament bundles in the ribbon, including overlapping defects and gap defects. The defect localization algorithm locates the defect areas by calculating the relative positional relationship between adjacent ribbon boundaries and uses triangulation to calculate the precise area of ​​irregular defect areas. The identified defect area information is integrated into the data structure of the filament placement unit for optimizing subsequent filament placement paths.

[0021] In a preferred embodiment of the present invention, when the filament placement equipment executes the filament placement control command, it collects filament placement position data and angle data in real time through sensors integrated on the filament placement head, and compares these real-time data with the target motion path and filament placement angle in the command to calculate the position deviation and angle deviation. When any deviation value exceeds the preset tolerance range, the filament placement equipment control system immediately triggers the error correction process, corrects the motion trajectory by adjusting the servo motor operating parameters of the filament placement head, and dynamically updates the subsequent filament placement speed parameters to maintain filament placement continuity.

[0022] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0023] (1) By discretizing the component plane into a large number of finite element elements and identifying, calculating and assigning values ​​to the fiber angle and defect attributes of each element separately, it is possible to accurately describe the continuous change of the variable angle filament layup path and the microscopic distribution of embedded defects, which lays a reliable data foundation for subsequent high-fidelity finite element simulation and high-precision filament layup control, and fundamentally solves the problem that existing software cannot handle variable angle layup and microscopic defects.

[0024] (2) By introducing a defect location algorithm and simultaneously identifying and quantifying defect areas such as gaps and overlaps during the fabric layup generation stage, defect attributes are integrated as key parameters into the subsequent data stream. When generating fabric layup control instructions, the system can optimize and fine-tune the fabric layup path based on these defect data, realizing proactive avoidance or precise compensation for defects, thereby effectively reducing the performance degradation of components caused by defects and improving the quality and reliability of the final product.

[0025] (3) By using the radius of curvature judgment and constraint mechanism, it is ensured that the generated variable angle fiber layup path meets the minimum bending radius requirement of material layup, thus avoiding fiber breakage or wrinkling during the production process. At the same time, by combining the alternating layup principle and dynamic calculation of the fiber layup angle, not only is the symmetry and balance of the multi-layer structure layup guaranteed and the warping deformation caused by the process reduced, but also the anisotropic potential of the composite material is fully utilized by optimizing the fiber orientation, thereby significantly improving the overall structural strength and stability of the final component. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1This is a flowchart of the control method according to a preferred embodiment of the present invention. Detailed Implementation

[0028] 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.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0030] like Figure 1 As shown, the multi-directional wire placement control method for variable angle wire placement components includes the following steps:

[0031] S1. Obtain the fiber placement design parameters. The fiber placement design parameters include the starting point, starting angle, ending angle, path projection length, shape control parameters, and number of curve segments. The starting point represents the coordinates of the starting point of the fiber placement path on the component plane. The starting angle represents the fiber direction angle of the fiber placement path at the starting point. The ending angle represents the fiber direction angle of the fiber placement path at the ending point. The path projection length represents the total length of the fiber placement path on the projection plane. The shape control parameters are used to adjust the curvature of the fiber placement path. The number of curve segments represents the number of segments in which the fiber placement path is discretized. These fiber placement design parameters come from user input or pre-saved design files.

[0032] Based on the fiber placement design parameters, a reference path curve is generated through a path generation algorithm. The reference path curve represents the continuous fiber path of variable angle fiber placement. The path generation algorithm uses the starting point, starting angle, ending angle, path projection length, shape control parameters and the number of curve segments to perform mathematical modeling and output a discretized path point sequence.

[0033] The path generation algorithm specifically includes: generating a reference path curve based on the starting point, starting angle, ending angle, path projection length, shape control parameters, and the number of curve segments using a parametric curve equation. The parametric curve equation is either a cubic spline curve or a Bézier curve. The starting and ending angles are used as endpoint constraints, the shape control parameters as curvature adjustment factors, and the path projection length as a limit on the total curve length. The number of curve segments is used to discretize the curve into multiple line segments, each corresponding to a filament placement control point. These control points are used for subsequent path interpolation and filament placement head positioning. The path generation algorithm also includes path smoothing, generating a continuous path between control points using an interpolation algorithm to ensure the smoothness and executability of the filament placement path. The data output of the reference path curve is a sequence of coordinate points used for ply ribbon generation and filament placement control command generation.

[0034] In a preferred embodiment, the path generation algorithm uses a parametric curve equation (such as a cubic spline curve or a Bézier curve) to generate a reference path curve. Taking a cubic Bézier curve as an example, its mathematical expression is:

[0035] ;

[0036] In the formula, The coordinates of a point on the curve are a function of the parameter t; Indicates the coordinates of the starting point, which are derived from the starting point in the wire layup design parameters; The coordinates of the endpoint are calculated using the path projection length L and the starting point. ,in The termination angle is the coordinate of the termination point.

[0037] and The coordinates of the control points are used to adjust the curve shape; the calculation formula is:

[0038] ;

[0039] in: Indicates the starting angle, derived from the wire layup design parameters; The termination angle, representing the coordinates of the control point, is derived from the wire layup design parameters; The shape control parameter is used to adjust the curvature of the curve and is derived from the shape control parameter in the wire laying design parameters; t is the curve parameter, which is discretized by the number of curve segments n; the number of curve segments n means that the parameter curve is discretized into n segments, which are used for the generation of path point sequences and control point interpolation.

[0040] This formula ensures that the curve passes through the starting and ending points and satisfies the constraints of the starting and ending angles, while adjusting the curvature variation through the shape control parameter k. Path smoothing is achieved by generating a continuous path between control points using an interpolation algorithm, ensuring the smoothness of the wire-laying path.

[0041] For cubic spline curves, their construction is based on the starting point, ending point, starting angle, and ending angle as boundary conditions, employing either natural spline or fixed boundary spline methods. Specifically, the path projection length is divided into n equal intervals, each represented by a cubic polynomial, ensuring that the first derivative is continuous and equal to the starting and ending angles. Shape control parameters are used to adjust the tension factor of the spline curve to control curvature variations. The path point sequence is obtained by solving a tridiagonal matrix system, ensuring the curve is smooth and satisfies angular constraints.

[0042] S2. Based on the physical properties of the layup fibers, determine the reference value of the radius of curvature, and judge the curvature of the reference path curve based on the reference value of the radius of curvature. If the curvature exceeds the threshold, adjust the shape control parameters to regenerate the reference path curve to ensure the feasibility and stability of the layup path.

[0043] Curvature judgment specifically includes: determining the minimum curvature radius reference value based on the physical properties of the layup fibers; calculating the curvature radius of each point based on the mathematical description of the reference path curve; if the curvature radius of a point is less than the minimum curvature radius reference value, the curvature of that point is determined to be out of limit, and the path adjustment process is triggered. The path adjustment is achieved by modifying the shape control parameters, and the reference path curve is regenerated until the curvature radius of all points meets the requirements. Curvature judgment also includes curvature consistency checks to ensure that the curvature change of the entire path is smooth and to avoid sharp bending that leads to layup defects. The curvature radius reference value comes from the material mechanical property test data and is matched with the maximum bending capacity of the layup equipment. The output of curvature judgment is a qualified reference path curve, which is used for subsequent layup ribbon generation.

[0044] Curvature determination is based on the mathematical description of the reference path curve, calculating the radius of curvature and comparing it with the minimum radius of curvature reference value. For parametric curves... curvature The calculation formula is:

[0045] ;

[0046] radius of curvature for:

[0047] ;

[0048] in:

[0049] and It represents the first derivative of the curve at the parameter t, and represents the components of the tangent vector;

[0050] and This represents the second derivative of the curve at parameter t, and represents the rate of change of curvature.

[0051] This represents the curvature at parameter t;

[0052] This represents the radius of curvature at parameter t.

[0053] Curvature determination process:

[0054] Calculate the minimum radius of curvature reference value The data is derived from material mechanical property test data and is matched with the maximum bending capacity of the wire laying equipment.

[0055] Minimum radius of curvature reference value The maximum allowable strain of the fiber was determined through material mechanical property testing. and fiber bundle thickness calculate: .in, The maximum bending capacity of the fiber placement equipment must meet the requirements provided by the fiber material supplier or obtained through tensile testing. The requirement is to avoid fiber breakage or wrinkling. For example, for carbon fiber composites, Typically, it is 1.5%, and the fiber bundle thickness is 0.2 mm. The calculated value is 6.67 mm.

[0056] For each discrete point ,calculate ,like If the curvature exceeds the limit, the path adjustment process will be triggered.

[0057] Path adjustment is achieved by modifying shape control parameters. To achieve this, regenerate the reference path curve until all points satisfy the condition. .

[0058] Curvature consistency check is performed by calculating the rate of change of curvature between adjacent points. Ensure the changes are smooth and avoid sharp bends.

[0059] S3. Obtain production parameters, including the fiber bundle width and the number of fiber bundles in the ribbon. The fiber bundle width represents the physical width of a single fiber bundle, and the number of fiber bundles in the ribbon represents the number of fiber bundles contained in a fiber laying unit. These production parameters are derived from the production equipment configuration or process specifications.

[0060] Based on production parameters and reference path curves, layup ribbons are generated using equidistant curve generation, extension curve generation, and interpolation curve generation methods. Layup ribbons represent layup units composed of multiple filament bundles. The equidistant curve generation method uses the reference path curve as a reference and offsets according to the filament bundle width to generate multiple parallel paths. The extension curve generation method extends the path length to cover the component edge. The interpolation curve generation method fills the path gaps to improve path continuity.

[0061] The ply ribbon generation process specifically includes: using a reference path curve as a baseline, generating multiple parallel paths based on the filament width and the number of filaments in the ribbon using an equidistant curve generation method. The equidistant distance is calculated based on the filament width, and the number of parallel paths equals the number of filaments in the ribbon. An extension curve generation method is used to extend the paths to the component boundary, ensuring that the ply covers the entire plane through linear or nonlinear extension. An interpolation curve generation method is used to fill the gaps between paths, improving path continuity through spline interpolation or linear interpolation. After generating the ply ribbon, a ribbon width consistency check is performed, and the path spacing is adjusted according to production parameters to ensure that the ribbon width matches the filament width. The ply ribbon data output is a set of multiple path curves used for starting point adjustment and ribbon translation.

[0062] Layered ribbon generation is achieved through equidistant curves, extended curves, and interpolated curves. Taking equidistant curve generation as an example, for the reference path curve... Its equidistant curves The generating formula is:

[0063] ;

[0064] in:

[0065] Indicates the first The coordinates of points on the equidistant curves .

[0066] This represents the coordinates of a point on the reference path curve.

[0067] This represents the offset distance, calculated using the following formula: ,in:

[0068] This indicates the width of the filament bundle, derived from production parameters.

[0069] This indicates the number of strands in the ribbon, derived from production parameters.

[0070] The unit normal vector is calculated using the following formula: ,in and This is the first derivative of the reference path curve.

[0071] The extension curve is generated by extending the linear extension path to the component boundary:

[0072] ;

[0073] in:

[0074] This represents the points on the extended curve.

[0075] This indicates the extension length, which is dynamically calculated based on the component boundary position.

[0076] Extension length Dynamic calculations are performed based on the component boundary positions. Specifically, using the component's planar boundary coordinates as a basis, the Euclidean distance between the current path endpoint and the nearest boundary point is calculated, taking into account the influence of the ribbon width. ,in These are the coordinates of the boundary points. The coordinates of the current path endpoint. Represents the width of a single filament bundle. This represents the number of filament bundles contained in a single filament-laying unit (i.e., a ribbon). This is the overall width of the ply ribbon. The extension direction is along the unit tangent vector. Ensure the path extends to the boundary with slight overlap to avoid uncovered areas.

[0077] The unit tangent vector is represented by the following formula: .

[0078] Interpolation curve generation uses linear interpolation to fill path gaps:

[0079]

[0080] in:

[0081] This represents a point on the interpolation curve.

[0082] and Indicates the endpoints of adjacent paths.

[0083] These are the interpolation parameters.

[0084] After generating the lay-up ribbons, a ribbon width consistency check is performed to ensure the ribbon width is consistent. Matches the path spacing.

[0085] S4. According to the predefined laying principle, adjust the starting point so that the first lay-up ribbon covers the starting part of the component plane. The laying principle is from bottom to top and from left to right. The adjusted starting point is determined by calculating the coordinates of the end point of the lay-up ribbon and translating it along the negative direction of the coordinate axis to ensure the integrity of the lay-up coverage.

[0086] The specific layup principles and starting point adjustments include: determining the initial coverage area of ​​the component plane according to the layup sequence from bottom to top and from left to right, calculating the coordinates of the end point of the first layup ribbon, and adjusting the starting point through coordinate transformation to ensure that the adjusted starting point ensures that the first ribbon covers the lower right corner area. The adjustment amount is calculated based on the ribbon width and the number of filaments, and is translated along the negative y-axis. The translation distance is determined based on the difference between the coordinates of the ribbon end point and the target starting point. The layup principles also include optimizing the filament layup direction, dynamically selecting the layup starting point according to the component shape and stress distribution to maximize coverage efficiency and structural strength. The adjusted starting point is used to initialize the position of the layup ribbon and provide input data for the ribbon translation.

[0087] Based on the adjusted starting point, the curve path information of the entire component plane is generated by the ribbon translation method. The curve path information includes the path data of all lay-up ribbons. The ribbon translation method calculates the translation distance based on the ribbon width and the number of ribbons in the ribbon, and applies iteratively until the entire component plane is covered.

[0088] The ribbon translation method specifically includes: based on the adjusted starting point, calculating the translation distance according to the ribbon width and the number of ribbons in the ribbon, wherein the translation distance increases iteratively along the laying direction, and each translation generates a new lay-up ribbon until the entire component plane is covered. The ribbon translation also includes boundary processing, adjusting the translation path by detecting the component boundary to avoid ribbon overflow or uncovered areas. After generating the curved path information of the entire component plane, the path data is integrated, merging multiple ribbon paths into a unified path point sequence and storing it as a data structure for multi-layer lay-up generation and ribbon laying control command generation. The curved path information also includes path topology relationships for subsequent ribbon laying sequence optimization.

[0089] The ribbon translation method generates the curve path information for the entire component plane through iterative translation. Translation distance. The calculation formula is:

[0090] ;

[0091] in:

[0092] This indicates the distance of each translation.

[0093] This indicates the width of the filament bundle, derived from production parameters.

[0094] This indicates the number of strands in the ribbon, derived from production parameters.

[0095] This represents the overlap coefficient, used to control the degree of overlap between ribbons, and is typically set to a value of [value missing]. This originates from the process specifications.

[0096] Translation process:

[0097] From the adjusted starting point Initially, the first translation generates the position of the new ribbon. ,in:

[0098] Indicates the current position of the ribbon.

[0099] This represents the unit vector indicating the tile direction, determined according to the tile placement principle (from bottom to top, from left to right). or .

[0100] Iterative translation until the entire component plane is covered, with boundary checks after each translation to prevent ribbon overflow.

[0101] S5. For multi-layer ply, the alternating ply principle is adopted to generate the curve path information of each layer. For even-numbered layers, the alternating ply is performed directly, and for odd-numbered layers, the alternating ply is performed with the intermediate layer being a positive single layer, so as to achieve ply symmetry and defect balance.

[0102] The alternating layup principle specifically includes: for multi-layer layups, different layup strategies are adopted according to the parity of the layup sequence number. Even-numbered layers are directly symmetrically alternated, while odd-numbered layers are set with the intermediate layer as a positive single layer based on the alternating layup to achieve layup symmetry and defect balance. Alternating layup also includes layup angle optimization. The layup angle distribution is calculated based on the curve path information of each layer, and the layup sequence is adjusted to maximize the isotropy of the composite material. The output of the alternating layup principle is a set of multi-layer curve path information. The path data of each layer includes the path point sequence and layup angle, which are used to generate fiber placement control commands. The layup angle comes from the reference path curve and curve path information.

[0103] S6. Based on the curve path information of each layer, generate the fiber placement control command. The fiber placement control command includes the movement path of the fiber placement head, the fiber placement angle and the fiber placement speed. The movement path comes from the path point sequence in the curve path information, and the fiber placement angle is dynamically calculated according to the fiber direction angle at the path point.

[0104] The generation of fiber placement control instructions specifically includes: extracting path point sequences and layup angles based on the curve path information of each layer; generating the motion path of the fiber placement head through a motion planning algorithm, wherein the motion path includes straight lines and curved segments; the fiber placement angle is dynamically calculated based on the fiber direction angle at the path point and incorporates angle smoothing processing to ensure fiber placement continuity; the fiber placement control instructions also include fiber placement speed parameters, which are dynamically adjusted according to the path curvature and fiber placement material characteristics to improve fiber placement quality and efficiency; the generation of fiber placement control instructions also includes instruction encoding, which converts the motion path, fiber placement angle, and fiber placement speed into executable code for the device and outputs it to the control interface for fiber placement equipment control.

[0105] The motion planning algorithm employs a linear interpolation combined with an acceleration constraint strategy. The path point sequence generates a continuous motion trajectory through spline interpolation, and the acceleration of the filament-laying head is considered. and accelerometer Limitations are in place to ensure smoothness. Fiber placement speed. Dynamically adjust based on path curvature: ,in For the maximum permissible speed, The curvature of the current path point. This is a material property coefficient (calibrated experimentally). Angle smoothing is achieved using quaternion interpolation to ensure continuous change in the fiber placement head direction.

[0106] The fiber placement control command is sent to the fiber placement equipment to control the fiber placement head to perform multi-directional fiber placement operations according to the movement path and fiber placement angle, thereby dynamically adjusting the fiber placement angle and path to improve the structural strength of composite materials.

[0107] The control of the fiber placement equipment specifically includes: receiving fiber placement control commands, parsing the command content through the equipment drive module, controlling the fiber placement head to move along the motion path, and dynamically adjusting the fiber placement angle and speed. The fiber placement angle adjustment is based on the angle data at the path point in real time, and the fiber placement speed is optimized according to the path curvature and equipment performance. The control of the fiber placement equipment also includes real-time monitoring, using sensors to feed back the fiber placement position and angle, comparing it with the command data and performing error correction to ensure fiber placement accuracy. After the fiber placement is completed, a fiber placement quality report is output, including data on fiber placement path deviation and angle consistency, for process optimization.

[0108] The error correction process employs a PID control algorithm. Position deviation. and angle deviation As input, servo motor control signal The calculation is as follows: ,in For the deviation vector, These are the gain parameters obtained through equipment calibration. Control signals are sent to the servo driver in real time to dynamically adjust the motor torque and speed, while simultaneously updating the subsequent wire placement speed to maintain continuity.

[0109] In a preferred embodiment, the plane of the filament-lay component is discretized to generate a large number of finite element elements, thus establishing a finite element mesh. Since the layup thickness is much smaller than the component size, shell elements are used, preferably quadrilateral shell elements composed of four nodes. The boundary is divided into several equal parts along the x-axis and y-axis to generate the mesh. The element mesh size is determined by production parameters such as the filament width and the number of filaments in the ribbon, to ensure a balance between computational accuracy and efficiency in the finite element model with embedded defects. Node location information and the structural relationships between elements and nodes are written into a programming file to generate the finite element mesh.

[0110] To avoid misjudgment of fiber angles and defect identification errors caused by mismatch between unit grid size and fiber bundle width, the fiber bundle is divided into equal parts. The number of equal parts is determined based on the unit grid size, and the defect location process is completed by distinguishing between the original number of fiber bundles and the number of fiber bundles after equal division.

[0111] Number of equal parts Based on cell grid size and fiber bundle width calculate: The original filament path was divided into equal parts. Sub-paths, each sub-path having a width of The fiber angle within a cell is taken as the weighted average of all sub-path angles, with the weight being the proportion of the sub-path's length within the cell.

[0112] When determining the fiber angle of a unit cell, the boundary data of each unit cell is interpolated to ensure the integrity of the path information. According to the rules of the reference path curve, there are four types of fiber path crossings within each unit cell. For the left and right boundaries, the x-axis data is interpolated; for the top and bottom boundaries, the y-axis data is interpolated. If the horizontal coordinate interval of the ribbon data includes the unit cell size, the interpolation of the x-axis data can be reduced. This interpolation-completed data provides a basis for determining the angle attribute.

[0113] Based on the fiber path information within each cell, the fiber angle of each cell is determined. After dividing the fiber bundle equally and interpolating the cell boundary data, all path curve segments are extracted from each cell grid region, and the fiber angle at the geometric center of each path curve segment is calculated. If there are more than three path curves in the region, the fiber angles are sorted and the average of the top three is taken as the fiber angle of the cell grid; if there are fewer than three, the average is taken directly.

[0114] The method provided by this invention also includes defect avoidance processing: after generating the layup ribbon, potential defect areas, including overlapping and gap defects, are identified based on a defect localization algorithm, and the layup ribbon path is adjusted according to the defect areas to avoid the generation of defects. The defect localization algorithm calculates the defect probability using the filament width and the number of filaments in the ribbon, and reduces the impact of defects by path offset. The defect avoidance data is integrated into the curve path information for the generation of layup control instructions, ensuring that defects are minimized during the layup process and improving the structural strength of the composite material.

[0115] The defect localization algorithm calculates the normal distance between adjacent ribbon boundaries. Identify defects. For two adjacent paths... and Calculate the normal distance at the point corresponding to parameter t: .like If it is, then it is identified as a gap defect; if If any of the points exceed the limit, it is identified as an overlapping defect. The defect area is formed by connecting all the points exceeding the limit to create a polygon, and the area is calculated using triangulation.

[0116] Defect avoidance processing is based on defect location algorithms to identify overlapping and gap defects. (Defect area) Calculated using the triangulation method:

[0117] ;

[0118] in:

[0119] The vertex coordinates of the polygon representing the defect area are obtained through a defect localization algorithm.

[0120] This indicates the number of sides of the polygon.

[0121] When summing, use the modulo operation to ensure that the area is positive.

[0122] Defect probability The calculation formula is:

[0123]

[0124] in:

[0125] The area of ​​a single cell is represented by the following formula: ,in This represents the cell grid size.

[0126] when hour, The defect threshold triggers path offset adjustment to reduce the impact of defects.

[0127] Path offset adjustment is achieved by modifying the offset distance in the isometric curve. To achieve, for example, by adjusting To reduce overlap or gaps.

[0128] Defect threshold Based on process specifications and empirical data, the value is typically set to 0.05 to 0.1, indicating that path offset is triggered when the defect area accounts for more than 5% to 10% of the unit area. Path offset is adjusted by regulating the offset distance of the equidistant curve. Implementation: For gap defects, reduce For overlapping defects, increase Offset ,in To optimize the coefficients, iterative calculations are performed until... .

[0129] Based on the preferred embodiments of the present invention described above, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method of multi-axial tows placement control for a variable angle tow placement member, characterized in that, The method comprises the following steps: S1, obtaining a filament laying design parameter, and generating a reference path curve through a path generation algorithm; the filament laying design parameter comprises a starting point, a starting angle, a terminal angle, a path projection length, a shape control parameter, and a curve segment number; S2, determining a curvature radius reference value according to the physical properties of the fiber of the laying layer, and judging the curvature of the reference path curve based on the curvature radius reference value, and if the curvature exceeds a threshold value, adjusting the shape control parameter to regenerate the reference path curve; S3, obtaining a production parameter comprising a towpiece width and a towpiece number in a towpiece tape, and generating a filament laying unit composed of multiple towpieces through an equidistant curve generation method, an extension curve generation method, and an interpolation curve generation method based on the production parameter and the reference path curve; S4, adjusting the starting point according to a predefined laying principle, and generating curve path information of the entire component plane through a towpiece tape translation method based on the adjusted starting point; S5, for multiple layers of laying, generating curve path information of each layer by adopting an alternating laying principle, wherein for even layers, the alternating laying is directly performed, and for odd layers, the alternating laying is performed and the middle layer is a positive single layer; S6, generating a filament laying control instruction based on the curve path information of each layer, and sending the filament laying control instruction to a filament laying device to control the filament laying head to perform a multidirectional filament laying operation according to a motion path and a filament laying angle, and dynamically adjust the filament laying angle and the path.

2. The multi-directional fiber placement control method of a variable angle fiber placement member according to claim 1, characterized by: The starting point represents the starting point coordinate of the filament laying path on the component plane, the starting angle represents the fiber direction angle of the filament laying path at the starting point, the terminal angle represents the fiber direction angle of the filament laying path at the terminal point, the path projection length represents the total length of the filament laying path on the projection plane, the shape control parameter is used to adjust the curvature change of the filament laying path, and the curve segment number represents the number of segments after the filament laying path is discretized.

3. The multi-directional filament placement control method of a variable angle filament placement member according to claim 2, characterized by: The path generation algorithm generates the reference path curve through a parametric curve equation according to the starting point, the starting angle, the terminal angle, the path projection length, the shape control parameter, and the curve segment number; wherein the parametric curve equation is a cubic spline curve or a Bezier curve, the starting angle and the terminal angle are used as end point constraints, the shape control parameter is used as a curvature adjustment factor, the path projection length is used as a total length limit of the curve, and the curve segment number is used to discretize the curve into multiple line segments, each line segment corresponding to a filament laying control point.

4. The multi-directional fiber placement control method of variable angle fiber placement members according to claim 1, characterized by: The generation process of the filament laying unit comprises: taking the reference path curve as a reference, generating multiple parallel paths through an equidistant curve generation method according to the towpiece width and the towpiece number in the towpiece tape; wherein the equidistant distance is calculated according to the towpiece width, the number of parallel paths is equal to the towpiece number in the towpiece tape, the extension curve generation method is used to extend the path to the component boundary, and linear or nonlinear extension is used to ensure that the laying layer covers the entire plane, and the interpolation curve generation method is used to fill the gap between the paths.

5. The multi-directional fiber placement control method of a variable angle fiber placement member according to Claim 1, characterized by: The laying principle is a laying sequence from bottom to top and from left to right, and the adjusted starting point is determined by calculating the end point coordinate of the laying layer towpiece tape and translating along the negative direction of the coordinate axis.

6. The multi-directional fiber placement control method of a variable angle fiber placement member according to Claim 1, characterized by: The tape translation method comprises: calculating a translation distance based on the adjusted starting point, according to the width of the tows and the number of tows in the tape, wherein the translation distance is iteratively increased along the laying direction, and each translation generates a new layer of tape until the entire component plane is covered.

7. The multi-directional fiber placement control method of a variable angle fiber placement member according to Claim 1, characterized by: The fiber laying control instruction is based on the curve path information of each layer, extracts the path point sequence and the laying angle, and generates the motion path of the fiber laying head through a motion planning algorithm; wherein the motion path includes straight line and curve segment, the fiber laying angle is dynamically calculated according to the fiber direction angle at the path point, and angle smoothing processing is integrated to ensure the continuity of fiber laying, the fiber laying control instruction further includes a fiber laying speed parameter, which is dynamically adjusted according to the path curvature and the fiber laying material characteristics.

8. The multi-directional fiber placement control method of variable angle fiber placement members according to claim 1, characterized by: In the process of generating the fiber laying unit, a defect positioning algorithm is synchronously executed, which identifies potential defect areas in the laying layer based on the width of the tows and the number of tows in the tape, including overlapping defects and gap defects. The defect positioning algorithm locates the defect area by calculating the relative position relationship between the boundaries of adjacent tapes, and calculates the accurate area of irregular defect areas by using the triangulation method; the identified defect area information is integrated into the data structure of the fiber laying unit.

9. The multi-directional fiber placement control method of variable angle fiber placement members of claim 1, wherein: When the fiber laying device executes the fiber laying control instruction, the sensor integrated on the fiber laying head collects real-time laying position data and angle data, and compares these real-time data with the target motion path and laying angle in the instruction, to calculate the position deviation and angle deviation; when any deviation value exceeds the preset tolerance range, the fiber laying device control system immediately triggers the error correction process, adjusts the operation parameters of the servo motor of the fiber laying head to correct the motion trajectory, and dynamically updates the subsequent fiber laying speed parameter.

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