Complex curved surface composite material double-stage laying path planning integrated optimization method

Abstract

The invention discloses a complex curved surface composite material double-stage laying path planning integrated optimization method, and belongs to the technical field of composite material automatic laying forming. The method specifically comprises the following steps: 1) establishing an initial ply design model; 2) based on the determined laying material, carrying out laying suitability analysis on the initial laying layer design model; 3) carrying out regional division on a laying curved surface structure of the laying layer design model suitable for laying, and determining laying process parameters of each path planning region; 4) in each path planning area, adopting a multi-constraint initial laying path generation method to generate an initial laying path; 5) adopting a multi-constraint optimized path densification method to generate an offset laying path; 6, laying path planning of all path planning areas in each laying layer.According to the automatic laying path planning method, by optimizing the generation method of the initial path and the offset path, the problem that laying process constraints are mutually restricted in the automatic laying process is solved, and the more accurate and efficient automatic laying path planning method is provided.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic placement and forming of composite materials, and particularly relates to an integrated optimization method for two-stage placement path planning of composite materials with complex curved surfaces. Background Art

[0002] Composite materials have become one of the important materials for modern high-performance structural components due to their excellent mechanical properties, lightweight characteristics, and high strength / weight ratio. However, the forming process of composite materials is complex. Especially when manufacturing large or complex structural components, how to accurately control the placement path of fibers and ensure the quality and efficiency of fiber placement has become the key to realizing the manufacture of high-performance composite materials.

[0003] Automatic fiber placement (AFP) technology, as an important technology in the manufacture of composite materials, is widely used in the production of high-performance composite materials. This technology uses an automated actuator to place prepreg fibers on the mold surface or prepreg layer in a certain trajectory and manner to achieve precise forming of composite materials. Compared with the traditional manual laying method, the automatic fiber placement technology has higher laying accuracy, repeatability, and production efficiency, and is particularly suitable for the manufacture of large-scale and highly complex composite material structures.

[0004] In the process of automatic wire placement, the path planning algorithm plays a vital role. Reasonable planning of the placement path not only affects the laying quality, but is also directly related to production efficiency, material utilization and the mechanical properties of the final product. The selection of the placement path in the automatic wire placement process must comprehensively consider multiple factors, such as placement angle deviation, prepreg tape gap, minimum turning radius of prepreg bundles, placement equipment performance, etc. At present, in automatic wire placement technology, the path planning algorithm faces the following challenges: (1) The problem of unified process constraints: Complex curved surface components may have regional personalized requirements due to actual stress conditions. Unified process constraints (such as placement angle deviation, prepreg tape gap, minimum turning radius of prepreg bundles, gap / overlap ratio) are often difficult to meet the production requirements of the entire complex curved surface component. (2) Limitations of single constraint control: For complex curved surface components, the initial placement path generated by a single constraint method cannot meet other process constraints. For example, the initial placement path generated based on the fixed angle method (considering only the placement angle deviation constraint) does not meet the constraint of the minimum turning radius of the prepreg tow, which may cause placement defects such as wrinkles; the initial placement path generated based on the geodesic method (considering only the minimum turning radius constraint of the prepreg tow) does not meet the constraint of the placement angle deviation. (3) Defects of the densification path generation algorithm: Densification path generation mainly refers to generating other offset paths based on the initial placement path. The equidistant densification method can avoid introducing gap / overlap defects, but on complex components, it may cause conflicts with other process constraints; the non-equidistant densification method can avoid conflicts with other process constraints, but it will cause more gap / overlap defects between adjacent placement paths. In addition, the overlapping interruptions between the placement paths make it difficult to fully utilize the excellent mechanical properties of the complete prepreg tow.

[0005] In summary, how to develop a placement path planning algorithm that adapts to the needs of different complex components under multiple process constraints, reduce defects such as gaps / overlaps and wrinkles introduced by placement path planning, and improve production efficiency and material utilization has become a hot issue in the research of automatic wire placement technology. Summary of the invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and provide an integrated optimization method for two-stage laying path planning of complex curved composite materials.

[0007] The specific technical solutions adopted by the present invention are as follows:

[0008] The present invention provides an integrated optimization method for two-stage laying path planning of complex surface composite materials, and the specific steps are as follows:

[0009] S1: Establish the initial layup design model for complex curved composite components;

[0010] S2: Based on the determined laying materials, conduct laying suitability analysis on the initial ply design model described in step S1 to obtain a ply design model suitable for laying.

[0011] S3: Divide the laying surface structure of the ply design model suitable for laying into several path planning regions, determine the laying process parameters for each path planning region.

[0012] S4: In each path planning region, based on the ply angle, ply angle deviation in the ply design parameters and the minimum turning radius of the prepreg tow in the laying process parameters, use the multi-constraint initial laying path generation method to generate the initial laying path for each path planning region.

[0013] S5: Take the initial laying path determined in step S4 as the benchmark, and generate an offset laying path through the path densification method with multi-constraint optimization; take the initial laying path or the offset laying path as the benchmark, and then generate other offset laying paths through the path densification method with multi-constraint optimization until the laying path covers each path planning region; complete the laying path planning for this path planning region.

[0014] S6: Repeat steps S4 and S5 to complete the laying path planning for all path planning regions in each ply.

[0015] S7: Use the equidistant offset technology to plan all prepreg tow laying paths based on the already planned laying paths.

[0016] Preferably, the initial ply design model described in step S1 includes the laying surface structure of the composite component and the ply design parameters; the specific method for establishing the initial ply design model is as follows:

[0017] S11: Determine the performance requirements that the composite component needs to meet according to the design requirements, including the strength, stiffness and weight of the composite component; determine the laying surface structure of the composite component according to the performance requirements.

[0018] S12: Establish the laying surface structure of the composite component in 3D software; based on the working load and force boundary conditions of the composite component, divide the laying surface structure according to different ply angles to obtain several path planning regions.

[0019] S13: According to the ply design parameters determined for each path planning region, determine the ply design scheme for this path planning region based on the symmetry principle and the balance principle to obtain a preliminary model; the ply design parameters include ply angle, stacking sequence, ply number, ply angle deviation and maximum tape gap width.

[0020] S14: Use finite element analysis software to perform a force analysis on the preliminary model; according to the results of the force analysis, repeatedly iterate and adjust the ply design scheme until an initial ply design model of the complex curved composite component that meets the design requirements is obtained.

[0021] Preferably, the laying suitability analysis described in step S2 is specifically as follows:

[0022] S21: Obtain the Gaussian curvature distribution of the laying curved surface structure of the initial ply design model;

[0023] S22: Based on the determined laying material, compare the minimum width of the prepreg tow with the laying width corresponding to the Gaussian curvature of each path planning area of the laying curved surface structure; if the minimum width of the prepreg tow is less than the laying width corresponding to the Gaussian curvature of each path planning area of the laying curved surface structure, the laying condition is satisfied;

[0024] S23: If the laying condition is not satisfied, re-optimize the laying curved surface structure of the composite component and then repeat steps S21 and S22 until a ply design model suitable for laying is obtained.

[0025] Furthermore, the laying process parameters include the width of the prepreg tow, the number of single-path prepreg tows, and the minimum turning radius of the prepreg tow; step S3 is specifically as follows:

[0026] S31: Obtain the directional curvature distribution of the laying curved surface structure of the ply design model suitable for laying;

[0027] S32: Based on the directional curvature distribution, determine the width of the prepreg tow, the number of single-path prepreg tows, and the minimum turning radius of the prepreg tow laid in each path planning area.

[0028] Preferably, the method for generating the initial laying path described in step S4 is specifically as follows:

[0029] S41: Select the starting path point of this path planning area, and use the fixed angle method to generate the second path point according to the ply angle in the ply design parameters and the path generation step size; the path generation step size is determined according to the directional curvature distribution of the laying curved surface structure;

[0030] S42: With the constraint that the geodesic curvature radius of the current path point is not less than the minimum turning radius of the prepreg tow of this laying material and the next path point is located on the laying curved surface structure, and with the minimum deviation of the ply angle at the current path point as the optimization goal, use the quadratic programming method to generate the next path point;

[0031] S43: Repeat step S42 until reaching the boundary of the path planning area to obtain the initial path point set of the path planning area; fit a curve based on the initial path point set to obtain the initial laying path of the path planning area.

[0032] Further, the method for generating the offset laying path in step S5 is specifically as follows:

[0033] S51: Discretize the initial laying path to obtain a number of discrete path points; multiply the width of the prepreg tow in the path planning area by the number of single - path prepreg tows to calculate the path offset reference distance.

[0034] S52: Based on the discrete path points, with the geodesic curvature radius of the current offset path point being not less than the minimum turning radius of the prepreg tow of the laying material, the actual path offset distance of the next offset path point being not less than the path offset reference distance and not higher than the sum of the path offset reference distance and the maximum band gap width, and the next offset path point being located on the laying surface structure as constraints, and with the minimum deviation of the ply angle at the current offset path point as the optimization objective, solve for the next offset path point.

[0035] S53: Repeat step S52 until the offset path points for each discrete path point are solved; determine whether the last offset path point reaches the boundary of the path planning area; if the last offset path point is not on the boundary of the path planning area, then use boundary - handling optimization to generate the next offset path point until the last offset path point is located on the boundary of the path planning area; fit a curve based on all the offset path points to obtain the offset laying path.

[0036] S54: Take the initial laying path or the offset laying path as the reference path, and repeat steps S52 and S53 until the full - covering target of the path planning area is completed.

[0037] Preferably, step S7 is specifically as follows:

[0038] Calculate the actual laying width corresponding to each laying path according to the laying process parameters of each path planning area; use the equidistant offset method to generate the prepreg tow laying paths for all path planning areas based on the actual laying width of each laying path.

[0039] The present invention has the following beneficial effects compared with the prior art:

[0040] (1)Partition and set process parameters to adapt to the requirements of complex surfaces: The present invention innovatively proposes a method for determining the laying process parameters by region. For different curvature regions of complex surface components, numerical simulation analysis is used to differentially select key parameters such as the width of a single prepreg tow and the number of single-pass prepreg tows. This method effectively solves the technical bottleneck that the traditional laying process with unified parameters is difficult to adapt to the characteristics of various parts of complex surfaces, significantly improves the laying accuracy and quality uniformity of complex surface components, and meets the stringent requirements for component performance under complex working conditions.

[0041] 2) Innovate the initial path method to ensure mechanical properties and laying quality: The initial path generation method proposed by the present invention fully considers the dual constraint conditions of ply angle deviation and measured curvature radius. During path planning, with the help of optimization theory and intelligent methods, it is ensured that the generated laying path not only conforms to the mechanical property indexes of the component, meets the requirements of load distribution and structural strength, but also avoids defects such as laying wrinkles caused by the measured curvature radius of the laying path being less than the minimum turning radius of the prepreg tow, guaranteeing high-quality component manufacturing from the source.

[0042] 3) Optimize the densification path with multiple constraints to reduce defects and improve laying quality: The present invention proposes a densification path generation method with multiple constraints optimized with the minimum ply angle deviation as the core optimization goal, and sets the surface equation, geodesic curvature radius, and with gaps, etc. as constraint conditions. Through non-linear programming and iterative optimization strategies, this method effectively overcomes the problems of excessive ply angle deviation and gap / overlap defects caused by the traditional equidistant densification method, greatly improves the overall quality and stability of the component, and meets the urgent needs of the high-end manufacturing field for high-precision and high-performance components. Description of the Drawings

[0043] Figure 1 is the flow chart of the optimization method provided by the present invention;

[0044] Figure 2 is the process diagram of the initial laying path generation in this embodiment;

[0045] Figure 3 is the process diagram of the offset laying path generation in this embodiment. Detailed Embodiments

[0046] The following further elaborates and explains the present invention in conjunction with the drawings and specific embodiments. The technical features of each embodiment in the present invention can be combined correspondingly without conflict.

[0047] As a preference of the specific embodiment of the present invention, this embodiment provides an integrated optimization method for the two-stage laying path planning of complex surface composites, and the process is as Figure 1 shown. The specific steps of this optimization method are as follows:

[0048] 1. Establish an initial ply design model for composite components with complex surfaces.

[0049] The initial ply design model includes the laying surface structure and ply design parameters of the composite component. The specific method for establishing the initial ply design model is as follows:

[0050] (1) Determine the performance requirements that the composite component needs to meet according to the design requirements, including the strength, stiffness, and weight of the composite component. Determine the laying surface structure of the composite component according to the performance requirements.

[0051] (2) Establish the laying surface structure of the composite component in 3D software, such as CAD software. Based on the working load and force boundary conditions of the composite component, divide the laying surface structure into several path planning regions according to different ply angles.

[0052] (3) Determine the ply design parameters for each path planning region, including ply angle, stacking sequence, ply number, ply angle deviation, and maximum tape gap width, etc. According to the determined ply design parameters, determine the ply design scheme for each path planning region based on the symmetry principle and balance principle to obtain a preliminary model.

[0053] Following the symmetry principle is to ensure that the plies are symmetric on both sides of the axis of symmetry. Through symmetric design, the coupling effects of tension-shear and tension-bending are avoided, and the warping deformation of the obtained composite material is avoided. Following the balance principle is to ensure the balance of the ply numbers in different directions to ensure the consistent mechanical properties of the structure in multiple directions. Those skilled in the art can determine the ply design scheme for each path planning region according to actual needs.

[0054] (4) Use finite element analysis software to perform a force analysis on the preliminary model. According to the force analysis results, if the preliminary model does not meet the design requirements, repeat step (3), and adjust the ply design scheme through repeated iteration until the initial ply design model of the composite component with complex surfaces that meets the design requirements is finally obtained.

[0055] 2. Laying suitability analysis

[0056] (1) Use the CATIA secondary development tool to obtain the Gaussian curvature distribution of the laying surface structure of the initial ply design model obtained in step 1.

[0057] (2)In this embodiment, the selected laying material grade is EH104 (1 / 4 inch, 6.35 mm). Based on the determined laying material, it is judged whether the laying material is suitable for laying on the curved surface structure. Specifically, it is to judge the minimum width of the prepreg tow and the laying width corresponding to the Gaussian curvature of the path planning area of the laying curved surface structure. If the minimum width of the prepreg tow is less than the laying width corresponding to the Gaussian curvature of each path planning area of the laying curved surface structure, the laying condition is satisfied.

[0058] (3)If the laying condition is not satisfied, it is necessary to re-optimize the laying curved surface structure of the composite component, and then repeat the above steps (1) and (2) until a suitable laying ply design model is obtained.

[0059] III. Determine the laying process parameters for each path planning area

[0060] The laying curved surface structure of the suitable laying ply design model is meshed according to different laying angles to obtain several path planning areas. In this embodiment, the laying curved surface structure is divided into two path planning areas, namely S 1 and S 2 . Determine the laying process parameters for each path planning area, including the prepreg tow width, the number of single-path prepreg tows, and the minimum turning radius of the prepreg tow. The determination of the laying process parameters is as follows:

[0061] (1)Use the CATIA secondary development tool to obtain the directional curvature distribution of the laying curved surface structure of the suitable laying ply design model. The directional curvature reflects the degree of curvature of the curved surface in a certain direction. The larger the value, the more severely the curved surface is curved in that direction.

[0062] (2)Determine the prepreg tow width for laying in each path planning area according to the distribution of the directional curvature. In the area with a larger directional curvature, the prepreg tow width should be appropriately reduced to adapt to the curvature of the curved surface; in the area with a smaller directional curvature, a wider prepreg tow can be used to improve the laying efficiency. Select a suitable prepreg tow width to ensure that there are no problems such as wrinkles or fiber buckling during laying. The prepreg tow width is usually between 3.2 - 12.7 mm, and the specific width should be determined according to the distribution of the directional curvature and the requirements of the laying process.

[0063] Calculate the number of single-path prepreg tows required in each path planning area according to the area of the laying area and the width of the prepreg tow. In the area with a larger directional curvature, more tows may be required to cover the same area to ensure the laying quality.

[0064] Determine the minimum turning radius of the prepreg tow laid in each path planning area according to the distribution of the directional curvature. The minimum turning radius of the prepreg tow should be greater than the minimum bending radius corresponding to the directional curvature of the curved surface in this area to avoid wrinkles or fiber buckling during laying.

[0065] IV. Generation of the initial laying path

[0066] In each path planning area, based on the ply angle, ply angle deviation in the ply design parameters, and the minimum turning radius of the prepreg tow in the laying process parameters, use the multi-constraint initial laying path generation method to generate the initial laying path of each path planning area, as Figure 2 shown. The specific method is as follows:

[0067] (1) Select the starting path point 1 of the path planning area S , and use the fixed angle method to generate the first path point according to the ply angle in the ply design parameters and the path generation step size; the path generation step size is determined according to the distribution of the directional curvature of the laying curved surface structure.

[0068] (2) With the geodesic curvature radius of the current path point not less than the minimum turning radius of the prepreg tow of this laying material and the next path point located on the laying curved surface structure as the constraint conditions, and with the minimum ply angle deviation at the current path point as the optimization goal, use the quadratic programming method to generate the next path point , n≥2.

[0069] For example, to generate the third path point , it is necessary to use the geodesic curvature radius of the second path point not less than the minimum turning radius of the prepreg tow of this laying material as the first constraint condition, and the third path point located on the laying curved surface structure as the second constraint condition. Both the first constraint condition and the second constraint condition are satisfied, and with the minimum ply angle deviation of the second path point as the optimization goal, use the quadratic programming method to generate the third path point .

[0070] (3) Repeat the above step (2) until reaching the boundary of the path planning area S 1 , to obtain the initial path point set of this path planning area; fit a curve based on this initial path point set to obtain the initial laying path P 1 of the path planning area S 0 .

[0071] V. Generation of the offset laying path

[0072] Taking the initial laying path P determined in step four 0 as a reference, a bias laying path is generated by a path densification method with multiple constraints, as shown in Figure 3 the following. The specific method is as follows:

[0073] (1) Discretize the above initial laying path P 0 to obtain a number of discrete path points. Those skilled in the art can select an appropriate discretization degree according to actual needs to discretize the initial laying path P 0 . Multiply the width W of the prepreg tow in the path planning area by the number N of single-path prepreg tows to calculate the path bias reference distance . The width W of the prepreg tow generally takes 3.2 mm, 6.35 mm or 12.7 mm, and the number N of single-path prepreg tows generally takes 2, 4, 8, 16, 32, etc. In this embodiment, the number of single-path prepreg tows in the path planning areas S 1 and S 2 take 4 and 8 tows respectively, and the widths of the prepreg tows take 3.2 mm and 6.35 mm respectively

[0074] (2) Based on the discrete path points, with the geodesic curvature radius of the current bias path point not less than the minimum turning radius of the prepreg tow of the laying material, the actual path bias distance of the next bias path point not less than the path bias reference distance and not higher than the sum of the path bias reference distance and the maximum tape gap width, and the next bias path point being located on a complex curved surface as constraint conditions, and taking the minimum deviation of the ply angle at the current bias path point as the optimization objective, solve for the next bias path point , i≥3.

[0075] For example, to generate the third bias path point , it is necessary to take the geodesic curvature radius of the second bias path point not less than the minimum turning radius of the prepreg tow of the laying material as the first constraint condition, and the actual path bias distance of the third bias path point not less than the path bias reference distance and not higher than the sum of the path bias reference distance and the maximum tape gap width as the second constraint condition, and the third bias path point being located on the laying curved surface structure as the third constraint condition. While satisfying the first, second, and third constraint conditions, and taking the minimum deviation of the ply angle of the second bias path point as the optimization objective, use the quadratic programming method to generate the third bias path point .

[0076] It should be noted that when calculating the first offset path point and the second offset path point respectively, the first path point and the second path point are used as the benchmarks, and the first offset path point and the second offset path point are respectively obtained by offsetting with the calculated path offset reference distance .

[0077] (3) Repeat the above step (2), using each discrete path point as the benchmark to solve the corresponding offset path point. Determine whether the last offset path point reaches the boundary of the path planning region S 1 .

[0078] If the last offset path point is not on the boundary of the path planning region, the boundary processing optimization is used to generate the next offset path point. The fixed angle method or quadratic programming method in step four can be used to continue generating the remaining path points of the offset path

[0079] For example, taking the last offset path point generated above as the starting point, according to the ply angle in the ply design parameters and the path generation step length, the fixed angle method is used to continue generating the remaining path points of the offset path. Or, with the geodesic curvature radius of the offset path point to be continued not less than the minimum turning radius of the prepreg tow of the laying material and the offset path point to be continued located on the laying curved surface structure as the constraint conditions, and the minimum deviation of the ply angle at the offset path point to be continued as the optimization goal, the quadratic programming method is used to continue generating the path points

[0080] Until the last path point is located on the boundary of the path planning region; Fit a curve based on all offset path points to obtain the offset laying path P 1 .

[0081] (4) Taking the initial laying path P 0 or the offset laying path P 1 generated above as the reference path, repeat the above steps (2) and (3) until the full covering goal of the path planning region is completed, and the laying path planning of the path planning region S 1 is completed

[0082] VI. Refer to step four and step five to complete the laying path planning of another path planning region S 2 .

[0083] VII. Complete the laying path planning of the prepreg tow

[0084] According to the path planning region S1 and the path planning area S 2 For the laying process parameters of, calculate the actual laying width corresponding to each laying path. Using the equidistant offset method, based on the actual laying width of each laying path, generate the prepreg tow laying paths for all path planning areas.

[0085] VIII. Generate a numerical control (CNC) machining instruction set

[0086] (1) Discretize all prepreg tow laying paths according to a set step size to obtain a laying path information set, which specifically includes the three-dimensional coordinates of path points, normal vectors, and tangent vector information. This information is used to guide the precise operation of the laying equipment.

[0087] (2) Based on the prepreg tow path information, add the break-off information of the prepreg tow to the laying path information set. The break-off information includes the starting point, ending point of the prepreg tow, and the specific operation instructions for break-off, ensuring the correct laying and cutting of the prepreg tow during the laying process.

[0088] (3) Combine the parameters of the laying equipment and the laying path information set to compile a numerical control (CNC) machining instruction set.

[0089] The embodiments described above are only a preferred solution of the present invention, but it is not intended to limit the present invention. Those of ordinary skill in the relevant technical field can still make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all technical solutions obtained by adopting equivalent replacement or equivalent transformation methods fall within the protection scope of the present invention.

Claims

1. A two-stage placement path planning integrated optimization method for complex curved composite materials, characterized in that: The specific steps are as follows: S1: Establish the initial layup design model for complex curved composite components; S2: Based on the determined laying material, performing laying suitability analysis on the initial laying design model in step S1 to obtain a laying design model suitable for laying; S3: dividing the laying surface structure of the laying design model suitable for laying into regions to obtain a plurality of path planning regions, and determining laying process parameters for each path planning region; S4: In each path planning area, based on the ply angle and ply angle deviation in the ply design parameters and the minimum turning radius of the prepreg tow in the placement process parameters, a multi-constraint initial placement path generation method is used to generate an initial placement path for each path planning area; S5: using the initial placement path determined in step S4 as a reference, generating an offset placement path through a multi-constraint optimization path densification method; The initial placement path or the offset placement path is used as a reference, and then other offset placement paths are generated through the multi-constraint optimization path densification method until the placement path covers each path planning area; Complete the laying path planning of the path planning area; S6: repeating steps S4 and S5 to complete the laying path planning of all path planning areas in each layer; S7: Plan all prepreg tow placement paths based on the planned placement paths using the equidistant offset technique.

2. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: The initial ply design model in step S1 includes the placement surface structure of the composite component and ply design parameters; the method for establishing the initial ply design model is as follows: S11: Determine the performance requirements that the composite components need to meet based on the design requirements, including the strength, stiffness and weight of the composite components; determine the placement surface structure of the composite components based on the performance requirements; S12: Establishing a placement surface structure of the composite component in a three-dimensional software; dividing the placement surface structure according to different laying angles based on the working load and force boundary conditions of the composite component to obtain several path planning areas; S13: according to the ply design parameters determined for each path planning area, a ply design scheme for the path planning area is determined based on the principle of symmetry and the principle of balance to obtain a preliminary model; the ply design parameters include ply angle, stacking sequence, number of plies, ply angle deviation and maximum belt gap width; S14: Use finite element analysis software to perform stress analysis on the preliminary model; according to the stress analysis results, repeatedly adjust the layup design plan until an initial layup design model of the complex curved composite component that meets the design requirements is obtained.

3. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: The laying suitability analysis in step S2 is specifically as follows: S21: Obtaining Gaussian curvature distribution of the laying surface structure of the initial laying design model; S22: based on the determined laying material, comparing the minimum width of the prepreg tow of the laying material with the laying width corresponding to the Gaussian curvature of each path planning area of ​​the laying curved surface structure; if the minimum width of the prepreg tow is smaller than the laying width corresponding to the Gaussian curvature of each path planning area of ​​the laying curved surface structure, the laying condition is met; S23: If the laying conditions are not met, the laying surface structure of the composite component is re-optimized and steps S21 and S22 are repeated until a layup design model suitable for laying is obtained.

4. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 3 is characterized in that: The laying process parameters include the width of the prepreg tow, the number of prepreg tows in a single path and the minimum turning radius of the prepreg tows; step S3 is as follows: S31: obtaining a directional curvature distribution of a laying surface structure of a laying design model suitable for laying; S32: Determine the width of the prepreg tows laid in each path planning area, the number of prepreg tows in a single path, and the minimum turning radius of the prepreg tows based on the directional curvature distribution.

5. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: The initial laying path generation method in step S4 is specifically as follows: S41: selecting a starting path point of the path planning area, and generating a second path point by using a fixed angle method according to the ply angle and path generation step length in the ply design parameters; The path generation step length is determined according to the directional curvature distribution of the laid surface structure; S42: The geodesic curvature radius of the current path point is not less than the minimum turning radius of the prepreg tow of the laid material and the next path point is located on the laid surface structure as constraint conditions, the minimum layup angle deviation at the current path point is taken as the optimization goal, and the next path point is generated by using the quadratic programming method; S43: Repeat step S42 until reaching the boundary of the path planning area, and obtain an initial path point set of the path planning area; fit a curve based on the initial path point set to obtain an initial laying path of the path planning area.

6. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 5 is characterized in that: The offset placement path generation method in step S5 is specifically as follows: S51: discretizing the initial placement path to obtain a number of discrete path points; multiplying the prepreg tow width of the path planning area and the number of prepreg tows in a single path to calculate a path offset reference distance; S52: Based on discrete path points, with the constraints that the geodesic curvature radius of the current offset path point is not less than the minimum turning radius of the prepreg tow of the laid material, the actual path offset distance of the next offset path point is not less than the path offset reference distance and not higher than the sum of the path offset reference distance and the maximum belt gap width, and the next offset path point is located on the laid surface structure, and with the minimum ply angle deviation at the current offset path point as the optimization goal, solve the next offset path point; S53: Repeat step S52 until the offset path point solution of each discrete path point is completed; determine whether the last offset path point reaches the path planning area boundary; if the last offset path point is not on the path planning area boundary, use boundary processing optimization to generate the next offset path point until the last offset path point is on the path planning area boundary; fit the curve based on all the offset path points to obtain the offset paving path; S54: Using the initial paving path or the offset paving path as a reference path, repeating steps S52 and S53 until the path planning area achieves the full paving target.

7. The integrated optimization method for two-stage placement path planning of complex curved composite materials according to claim 1 is characterized in that: Step S7 is specifically as follows: The actual placement width corresponding to each placement path is calculated according to the placement process parameters of each path planning area; the equidistant offset method is used to generate the prepreg tow placement paths of all path planning areas based on the actual placement width of each placement path.

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