A method and device for planning fiber placement trajectory on complex curved surfaces

Abstract

The present invention relates to the field of carbon fiber composite material forming and manufacturing technology, and in particular to a method and device for planning fiber placement trajectories for complex curved surfaces. The method comprises: dividing the placement curved surface into several areas by setting a number of guide lines; determining the guide line in each area as the current trajectory, performing equidistant offset on the current trajectory, and determining the new trajectory as the current trajectory if the new trajectory obtained after each equidistant offset meets the corresponding desired placement direction requirements, otherwise the new trajectory is planned and adjusted according to the desired placement direction; during the equidistant offset process, the process stops when the boundary of the area or the next guide line is reached, and the trajectory planning of the workpiece to be placed is completed based on all the current trajectories obtained. This solves the problem that the existing placement trajectory planning method cannot meet the trajectory planning requirements when there are strict angle requirements or when the curved surface is relatively complex, and is prone to problems such as excessive gap overlap, processing wrinkles, and large deviations from the predetermined angle.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber composite material molding and manufacturing, and in particular to a method and device for planning a fiber placement trajectory for a complex curved surface. Background Art

[0002] Carbon fiber placement is a process in which continuous fibers are laid down in specific paths and angles, and then typically cured with a resin to form a composite material. This process enables the manufacture of complex-shaped parts with excellent strength and stiffness.

[0003] Trajectory planning is a key technology in carbon fiber placement. Its main function is to generate a placement trajectory based on the designed placement direction while minimizing defects such as overlap, gaps, and wrinkles. Currently, algorithms such as fully fixed angles and equidistant offsets are often used for simple components. However, on irregular surfaces or those with special angle requirements, these algorithms often result in excessive gap overlap, processing wrinkles, and large deviations from the predetermined angle, failing to meet the requirements.

[0004] Existing placement trajectory planning methods cannot fully address trajectory planning issues with strict angle requirements or complex curved surfaces. For example, projection is required when planning the placement trajectory, but many surfaces (such as surfaces of revolution) cannot be projected. The specific planning methods still use traditional fixed-angle or geodesic algorithms. Furthermore, their dense placement methods only use bandwidth variation and do not utilize the dynamic increase or decrease of placement, which cannot meet the requirements when the surface angle requirements are complex. Summary of the Invention

[0005] The present invention proposes a fiber placement trajectory planning method and device for complex curved surfaces to solve the problems that existing fiber placement trajectory planning methods cannot meet the trajectory planning requirements when there are strict angle requirements or the curved surfaces are relatively complex, and are prone to problems such as excessive gap overlap, processing wrinkles, and large deviations from the predetermined angle.

[0006] According to one aspect of the present invention, a method for planning a fiber placement trajectory on a complex curved surface is provided, comprising:

[0007] Obtaining a three-dimensional curved surface model of a workpiece to be wire laid, and dividing the laying surface of the three-dimensional curved surface model into a plurality of regions by setting a plurality of guide lines;

[0008] Determine the guide line in each area as the current trajectory, perform equidistant offsets on the current trajectory, and determine whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirements. If so, determine the new trajectory as the current trajectory. Otherwise, plan and adjust the new trajectory according to the expected placement direction, and determine the adjusted new trajectory as the current trajectory;

[0009] During the equidistant offset process, the process stops when reaching the boundary of the area or the next guide line, and the trajectory planning of the workpiece to be wire laid is completed based on all the current trajectories obtained.

[0010] Preferably, a closed curve for marking a laying area and / or a window opening area is provided on the laying surface of the acquired three-dimensional curved surface model;

[0011] Wherein, the boundary is: a closed curve of the laying area.

[0012] Preferably, the method of dividing the laying surface of the three-dimensional curved surface model into a plurality of areas by setting a plurality of guide lines includes:

[0013] Each of the regions is adjacent to at most two of the guide lines and at least one of the guide lines, and there is no intersection between the guide lines.

[0014] Preferably, the method for determining whether the new trajectory obtained after each equidistant offset meets the corresponding desired placement direction requirement includes:

[0015] Determine whether the workpiece to be laid has a certain axis. If so, the projection of the axis direction at any point on the new trajectory is the desired laying direction corresponding to the new trajectory.

[0016] If not, the desired laying direction corresponding to the new trajectory is determined according to the guide lines in the area.

[0017] Preferably, the method of determining the desired laying direction corresponding to the new trajectory according to the guide lines within the area includes:

[0018] If the area is adjacent to a guide line, then:

[0019] Determine the point P2 on the guide line corresponding to the point P1 on the new trajectory when the point P1 is closest to the guide line;

[0020] Determine the tangent direction V1 at point P2;

[0021] Determine the tangent plane S of the laid surface at point P1;

[0022] V2 obtained by projecting V1 onto S is the desired laying direction of point P1.

[0023] Preferably, the method of determining the desired laying direction corresponding to the new trajectory according to the guide lines within the area includes:

[0024] If the area is adjacent to two guide lines, then:

[0025] Determine the points P2 and P3 on the guide lines corresponding to when any point P1 on the new trajectory reaches the closest point between the two guide lines;

[0026] Determine the tangent directions V1 and V2 at points P2 and P3;

[0027] According to V1 and V2, determine the weighted direction V3 of the two guide lines;

[0028] Project V3 toward S to obtain the desired placement direction V4 of point P1;

[0029] and / or,

[0030] The method for determining the weighted direction V3 of the two guide line directions based on V1 and V2 includes:

[0031] The weighted direction V3 = d2*V1 + d1*V2;

[0032] Where: d1 is the distance from P2 to P1, d2 is the distance from P3 to P1.

[0033] Preferably, the method for determining whether the new trajectory obtained after each equidistant offset meets the corresponding desired placement direction requirement includes:

[0034] It is determined whether the angle between the new trajectory and the desired placement direction of the corresponding area does not exceed a predetermined value. If so, the new trajectory meets the corresponding desired placement direction requirement; otherwise, the new trajectory does not meet the corresponding desired placement direction requirement.

[0035] Preferably, the method for planning and adjusting the new trajectory according to the desired laying direction includes:

[0036] The direction of the new track is adjusted to the corresponding desired laying direction, and the distance between the new track and the previous current track is adjusted to minimize the overlap rate and gap rate between the two.

[0037] Preferably, the method for completing trajectory planning of a workpiece to be wire laid based on all obtained current trajectories includes:

[0038] The obtained current trajectory is divided into a laying area trajectory and a non-laying area trajectory using the closed curve;

[0039] The segmented current trajectory is discretized into trajectory points, and numerical control machining codes are generated according to the trajectory points.

[0040] According to one aspect of the present invention, a fiber placement trajectory planning device for a complex curved surface is provided, comprising:

[0041] A region segmentation unit is used to obtain a three-dimensional surface model of a workpiece to be wire laid, and to divide the laying surface of the three-dimensional surface model into a plurality of regions by setting a plurality of guide lines;

[0042] A trajectory determination unit is used to determine the guide line in each area as the current trajectory, perform equidistant offsets on the current trajectory, and determine whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirements. If so, the new trajectory is determined to be the current trajectory. Otherwise, the new trajectory is planned and adjusted according to the expected placement direction, and the adjusted new trajectory is determined to be the current trajectory.

[0043] The trajectory planning unit is used to stop when reaching the boundary of the area or the next guide line during the equidistant offset process, and complete the trajectory planning of the workpiece to be wire-laid based on all the current trajectories obtained.

[0044] The present invention has at least the following beneficial effects:

[0045] The present invention proposes a fiber placement trajectory planning method and device for complex curved surfaces. The method divides the area by setting guide lines, plans a trajectory with an angle consistent with the guide line at the guide line, and fully lays the fiber in the area divided by the guide line by adding or reducing fibers while meeting the angle requirements. This allows the design of the laying angle to have a high degree of freedom, allows the planned trajectory to be as consistent as possible with the design angle, and at the same time controls the gap and overlap within a smaller range. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0047] Figure 1 A flow chart showing a method for planning a fiber placement trajectory on a complex curved surface according to an embodiment of the present invention is shown;

[0048] Figure 2 A schematic diagram of guide lines on a placement surface according to an embodiment of the present invention is shown;

[0049] Figure 3 A schematic diagram of a fiber placement curved surface segmentation area according to an embodiment of the present invention is shown;

[0050] Figure 4 A schematic diagram showing a desired laying direction according to an embodiment of the present invention is shown;

[0051] Figure 5 A schematic diagram of a laying trajectory according to an embodiment of the present invention is shown;

[0052] Figure 6 A schematic diagram showing a non-laying trajectory line of a non-laying area according to an embodiment of the present invention;

[0053] Figure 7 A flow chart showing a method for determining a laying trajectory according to an embodiment of the present invention is shown;

[0054] Figure 8 A diagram showing a flat surface model according to an embodiment of the present invention is shown;

[0055] Figure 9 A diagram showing the results of wire laying trajectory planning for a flat surface model according to an embodiment of the present invention is shown;

[0056] Figure 10 The embodiment of the present invention is shown Figure 9 A partial enlarged view of

[0057] Figure 11 A diagram showing a C-beam curved surface model according to an embodiment of the present invention is shown;

[0058] Figure 12 A diagram showing the wire laying trajectory planning result of a C-beam curved surface model according to an embodiment of the present invention is shown;

[0059] Figure 13 The embodiment of the present invention is shown Figure 12 A partial enlarged view of . DETAILED DESCRIPTION

[0060] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0061] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0062] The term "and / or" herein simply describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of three situations: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

[0063] In addition, numerous specific details are provided in the following detailed description to better illustrate the present invention. Those skilled in the art will appreciate that the present invention may be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of the present invention.

[0064] Figure 1 Flowchart of the fiber placement trajectory planning method for complex curved surfaces; Figure 2 Schematic diagram of guide lines on the wire laying surface; Figure 3 Schematic diagram of the segmentation area of ​​the fiber placement surface; Figure 4 Schematic diagram of the desired laying direction;

[0065] Figure 5 This is a schematic diagram of the laying trajectory line; Figure 6 A schematic diagram of non-laying trajectory lines in the non-laying area; Figure 7 A flow chart of a method for determining a laying trajectory line; Figure 8 This is a flat surface model diagram; Figure 9 Result diagram of wire laying trajectory planning for flat surface model; Figure 10 for Figure 9 A partial enlarged view of Figure 11 This is the C-beam surface model diagram; Figure 12 This is the result diagram of wire laying trajectory planning for the C-beam surface model; Figure 13 for Figure 12 A partial enlarged view of the Figure 1-13 As shown, a fiber placement trajectory planning method for a complex surface includes: step S01: obtaining a three-dimensional surface model of a workpiece to be placed, and dividing the placement surface of the three-dimensional surface model into several areas by setting a number of guide lines; step S02: determining the guide line in each area as the current trajectory, performing equidistant offset on the current trajectory, and judging whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirement. If so, the new trajectory is determined to be the current trajectory; otherwise, the new trajectory is planned and adjusted according to the expected placement direction, and the adjusted new trajectory is determined to be the current trajectory; step S03: during the equidistant offset process, stopping when reaching the boundary of the area or the next guide line, and completing the trajectory planning of the workpiece to be placed according to all the current trajectories obtained.

[0066] The fiber placement trajectory planning method for a complex curved surface provided by an embodiment of the present invention specifically includes the following steps:

[0067] Step S01: obtaining a three-dimensional surface model of a workpiece to be wire laid, and dividing the laying surface of the three-dimensional surface model into a plurality of areas by setting a plurality of guide lines.

[0068] In an embodiment of the present invention, the obtained three-dimensional curved surface model of the workpiece to be wire laid includes a laying surface, which can be a plane, a curved surface, a combined curved surface or a special-shaped rotational surface.

[0069] In the present invention, a closed curve for marking a laying area and / or a window area is set on the laying surface of the acquired three-dimensional surface model; wherein the boundary is: the closed curve of the laying area.

[0070] In an embodiment of the present invention, a laying boundary composed of closed curves is provided on the laying surface of the three-dimensional curved surface model to mark the laying area. At the same time, a window boundary composed of closed curves can also be provided to mark the window area, that is, the area where no wire laying is performed.

[0071] On the laying surface of the 3D surface model, one or more penetrating guide lines are set at the same time to serve as the laying angle reference.

[0072] In the present invention, the method of dividing the laying surface of the three-dimensional surface model into several areas by setting several guide lines includes: each of the areas is adjacent to at most two of the guide lines and at least one of the guide lines, and there is no intersection between the guide lines.

[0073] In this embodiment of the present invention, guide lines are set to divide the placement surface into multiple regions, with each region adjacent to at most two guide lines and at least one guide line. If the three-dimensional surface model of the workpiece to be laid has edges, guide lines need to be set along the edges according to the desired placement direction or force direction.

[0074] like Figure 2 As shown, a laying boundary 2 and a laying window boundary 3 , as well as a first guide line 4 and a second guide line 5 are set on the laying surface 1 .

[0075] like Figure 3 As shown, the first guide line and the second guide line divide the placement surface 1 into three independent areas, namely area 1, area 2 and area 3. Area 1 is adjacent to the first guide line 4, area 2 is adjacent to the first guide line 4 and the second guide line 5, and area 3 is adjacent to the second guide line 5.

[0076] Step S02: Determine the guide line in each area as the current trajectory, perform equidistant offsets on the current trajectory, and determine whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirements. If so, determine the new trajectory as the current trajectory. Otherwise, plan and adjust the new trajectory according to the expected placement direction, and determine the adjusted new trajectory as the current trajectory.

[0077] In the present invention, the method for judging whether the new trajectory obtained after each equidistant offset meets the corresponding expected laying direction requirements includes: judging whether the workpiece to be laid has a certain axis. If so, the projection of the axis direction at any point on the new trajectory is the expected laying direction corresponding to the new trajectory; if not, the expected laying direction corresponding to the new trajectory is determined according to the guide line in the area.

[0078] In the embodiment of the present invention, the desired placement direction of any point in each area can be determined by various methods, such as an axis or a guide line.

[0079] When the direction field is established with an axis, the expected laying direction of any point on the new trajectory in the area is the projection of the axis direction of the surface of the workpiece to be laid at that point.

[0080] When establishing a direction field using guide lines, the desired placement direction of any point on the new trajectory within the area is determined by the directions of the adjacent guide lines and the distance from the point to the guide line. The shorter the distance between the point and the guide line, the greater the influence of the guide line on the placement direction.

[0081] In the present invention, the method for determining the expected laying direction corresponding to the new trajectory based on the guide line in the area includes: if the area is adjacent to a guide line, then: determining the point P2 on the guide line corresponding to any point P1 on the new trajectory when the distance to the guide line is the shortest; determining the tangent direction V1 at point P2; determining the tangent plane S of the laying surface at point P1; and projecting V1 onto S to obtain V2 as the expected laying direction of point P1.

[0082] In the embodiment of the present invention, when establishing a direction field with a guide line, if there is only one guide line in the area, such as Figure 3 As shown in regions 1 and 3 in the figure, the new trajectory g in the region is determined by a single guide line. now The expected laying direction of any point on the surface, if there are two guide lines in the area, such as Figure 3 As shown in area 2, the new trajectory g in the area is determined by two guide lines. now The desired laying direction at any point on the

[0083] The method for determining the desired laying direction using a single guide line is:

[0084] Determine the new trajectory g in the area now For any point P1 on the guide line of the area, find the point P2 that is closest to P1;

[0085] Determine the tangent direction V1 of the guide line at point P2;

[0086] Determine the tangent plane S of the laid surface at point P1;

[0087] Project V1 to S to get V2, then V2 is point P1, that is, the new trajectory g now The corresponding expected laying direction.

[0088] In the present invention, the method for determining the expected placement direction corresponding to the new trajectory based on the guide lines in the area includes: if the area is adjacent to two guide lines, then: determining the points P2 and P3 on the guide lines corresponding to the point P1 on the new trajectory when the distance between the two guide lines is the shortest; determining the tangent directions V1 and V2 at points P2 and P3; determining the weighted direction V3 of the directions of the two guide lines based on V1 and V2; projecting V3 toward S to obtain the expected placement direction V4 of point P1; and / or, the method for determining the weighted direction V3 of the directions of the two guide lines based on V1 and V2 includes:

[0089] The weighted direction V3 = d2*V1 + d1*V2 (1);

[0090] Where: d1 is the distance from P2 to P1, d2 is the distance from P3 to P1.

[0091] In an embodiment of the present invention, the method for determining the laying direction by two guide lines is:

[0092] Determine the new trajectory g in the area now For any point P1 on the surface, find the points P2 and P3 closest to P1 on the two guide lines in the area, as well as the distances d1 and d2 between P1, P2 and P3;

[0093] Determine the tangent directions V1 and V2 of the guide line at points P2 and P3;

[0094] Determine the tangent plane S of the laid surface at point P1;

[0095] According to the tangent directions V1 and V2, use formula (1) to determine the weighted direction V3 of the two guide line directions;

[0096] Project the weighted direction V3 onto the tangent plane S to obtain V4, then V4 is point P1, that is, the new trajectory g now The corresponding expected laying direction.

[0097] like Figure 4 As shown, the desired laying angle field of each area based on the first guide line 4 and the second guide line 5 is shown. Figure 4 6, 7, and 8 are the new trajectories g in the three segmented areas. now Any point on .

[0098] The area where point 6 is located is adjacent only to the first guiding line 4, so its expected angle (expected placement direction) is determined by the first guiding line 4. Similarly, the area where point 8 is located is adjacent only to the second guiding line 5, so its expected angle is determined by the second guiding line 5. The area where point 7 is located is adjacent to both the first and second guiding lines 4 and 5, so its expected angle is determined by both guiding lines.

[0099] In the present invention, a method for determining whether a new trajectory obtained after each equidistant offset satisfies the corresponding desired placement direction requirement includes: determining whether an angle between the new trajectory and the corresponding desired placement direction of the area does not exceed a predetermined value; if so, the new trajectory satisfies the corresponding desired placement direction requirement; otherwise, the new trajectory does not meet the corresponding desired placement direction requirement.

[0100] In the embodiment of the present invention, Figure 7 FIG. 1 is a flowchart of determining the current trajectory in each area. The method for determining the current trajectory in each area, that is, the specific process of step S02 is as follows:

[0101] Step S02.1: Generate a guideline trajectory g1 in the area strictly according to the direction of the guideline; if there are two guidelines, generate two guideline trajectories g1 and g2; use the guideline trajectory g1 or g1 and g2 as the current trajectory g current ;

[0102] Step S02.2: For the current trajectory g current Perform equidistant offset, the direction of the equidistant offset is the direction away from the guide line in the area, and the new trajectory g is obtained after the equidistant offset now ;

[0103] Step S02.3: Determine the new trajectory g now Does the matching degree between the new trajectory g and the corresponding expected laying direction meet the predetermined requirements? If yes, then the new trajectory g is determined. now is the current trajectory g current , otherwise, for the new trajectory g now Re-plan and adjust the desired laying direction of the area and determine the new trajectory g after adjustment now is the current trajectory g current .

[0104] The preset value ranges from 5 to 10 degrees.

[0105] In the present invention, the method for planning and adjusting the new trajectory according to the expected laying direction includes: adjusting the direction of the new trajectory to the corresponding expected laying direction, and at the same time adjusting the distance between the new trajectory and its previous current trajectory to minimize the overlap rate and gap rate between the two.

[0106] In the embodiment of the present invention, the new trajectory g now The direction is adjusted to the corresponding desired laying direction, and the new trajectory g is adjusted at the same time now Its previous current trajectory g current , that is, the distance between the current trajectories before the equidistant offset, so that the gap between the two is minimized under the set overlap rate.

[0107] Step S03: During the equidistant offset process, the process stops when reaching the boundary of the area or the next guide line, and completes the trajectory planning of the workpiece to be wire laid based on all the current trajectories obtained.

[0108] In the present invention, the method for completing the trajectory planning of the workpiece to be wire-laid based on all the current trajectories obtained includes: dividing the current trajectory obtained into a laying area trajectory and a non-laying area trajectory using the closed curve; discretizing the divided current trajectory into trajectory points, and generating CNC machining code based on the trajectory points.

[0109] In the embodiment of the present invention, step S03.1: repeat steps S02.2 to S02.3 until the boundary of the laying area of ​​the area is reached or the next guide line is reached, then all the current trajectories g are obtained. current Lay out the track lines for the area.

[0110] Step S03.2: Repeat steps S02.1 to S03.1 to obtain the laying trajectory lines of all areas.

[0111] like Figure 5 As shown, in Figure 5 9 and 10 are two new trajectories g1 and g2 generated based on the first guide line 4 and the second guide line 5, and then offset by equal distance. now , the new trajectory is the two laying trajectory lines.

[0112] After all the laying trajectory lines are obtained, the laying trajectory lines are divided into laying area trajectories and non-laying area trajectories according to the laying area and window area boundaries marked by closed curves. Figure 6 As shown, a planned laying trajectory line is shown, which is divided into a laying trajectory line 12 and a non-laying trajectory line 11 by the boundary of the laying area and the window area.

[0113] Each laying trajectory line is discretized into trajectory points, and the NC machining code is generated based on this.

[0114] like Figure 8As shown, a flat-plate model surface is input, the dotted line is a closed laying boundary line, and the two solid lines are penetrating guide lines. According to the present invention, the two guide lines will first divide the model surface into three areas, and then the wire laying trajectory planning is performed for each of the three areas. During the planning process, the expected laying direction field of any point of the new trajectory in the three areas is determined. If the two boundary areas are adjacent to only one guide line, their expected direction is the same as the adjacent guide line. The middle area is adjacent to two guide lines, and its expected direction is the weighted direction of the two guide lines. After planning, the trajectory is cut with the laying boundary line to determine whether the trajectory is within the laying area. Finally, the processing code is generated based on the laying trajectory. Figure 9 and 10 The results after trajectory planning are shown; Figure 10 In the figure a, Figure 9 The middle part is enlarged, and Figure b is Figure 9 The enlarged view of the edge shows that the guide line is completely consistent with the desired angle. The middle area is fully laid out by automatically adding or removing yarns, ensuring the laying angle and providing good control over overlap and gaps.

[0115] Figure 11 The input model surface for a C-beam consists of a closed placement boundary and two intersecting guide lines. The two guide lines divide the model surface into three regions, and placement trajectories are planned for each of these regions. After planning, the placement boundary is used to trim the trajectory to determine whether it falls within the placement area. Finally, machining code is generated based on the placement trajectory. Figure 12 and 13 The results after trajectory planning are shown, which demonstrates the ability of the method of the present invention to perform trajectory planning on combined surfaces. It can be seen that the guide line is completely consistent with the expected angle. The middle area is fully laid out by automatically adding or subtracting yarns, while ensuring the laying angle and having good control over overlap and gap.

[0116] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, the present invention will not elaborate on them.

[0117] The method for planning a fiber placement trajectory for a complex curved surface may be executed by a device for planning a fiber placement trajectory for a complex curved surface. For example, the method for planning a fiber placement trajectory for a complex curved surface may be executed by a terminal device, a server, or other processing device, wherein the terminal device may be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, an in-vehicle device, a wearable device, etc. In some possible implementations, the method for planning a fiber placement trajectory for a complex curved surface may be implemented by a processor invoking computer-readable instructions stored in a memory.

[0118] Those skilled in the art will understand that in the above-mentioned method of the specific implementation method, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0119] In the present invention, a fiber placement trajectory planning device for complex surfaces is also proposed, including: an area segmentation unit, used to obtain a three-dimensional surface model of a workpiece to be placed, and by setting a number of guide lines, the placement surface of the three-dimensional surface model is divided into a number of areas; a trajectory line determination unit, used to determine the guide line in each area as the current trajectory, equidistantly offset the current trajectory, and judge whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirement. If so, the new trajectory is determined to be the current trajectory; otherwise, the new trajectory is planned and adjusted according to the expected placement direction, and the adjusted new trajectory is determined to be the current trajectory; a trajectory planning unit, used to stop when reaching the boundary of the area or the next guide line during the equidistant offset process, and complete the trajectory planning of the workpiece to be placed according to all the current trajectories obtained.

[0120] In some embodiments, the functions or modules and units included in the device provided by the embodiment of the present invention can be used to execute the method described in the above method embodiment. Its specific implementation can refer to the description of the above method embodiment. For the sake of brevity, it will not be repeated here.

[0121] Mechanical or process constraints often impose multiple restrictions on placement angles. The method presented in this paper makes placement angle design more flexible. Using multiple guide lines, different angle benchmarks can be designed for different areas of the surface, ensuring that the angle at the guide lines strictly conforms to the angle benchmark. Within the guide line area, by adding or removing yarns, the placement angle can be brought close to the angle benchmark and within the allowable deviation. This effectively ensures that the placement angle meets design intent and process constraints, thereby achieving better mechanical properties and reducing processing defects.

[0122] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A fiber placement trajectory planning method for complex curved surfaces, characterized in that: include: Obtaining a three-dimensional curved surface model of a workpiece to be laid, and dividing the laying surface of the three-dimensional curved surface model into a plurality of regions by setting a plurality of guide lines, wherein each region is adjacent to at most two of the guide lines and at least one of the guide lines, and the guide lines do not intersect with each other; Determining the guide line in each area as the current trajectory, performing equidistant offsets on the current trajectory, and determining whether a new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirement, wherein the method includes: determining whether an angle between the new trajectory and the corresponding expected placement direction of the area does not exceed a predetermined value; if so, the new trajectory meets the corresponding expected placement direction requirement; otherwise, the new trajectory does not meet the corresponding expected placement direction requirement; The expected laying direction corresponding to the new trajectory is: judging whether the workpiece to be laid has a certain axis, and if so, the projection of the axis direction at any point on the new trajectory is the expected laying direction corresponding to the new trajectory; If not, the desired laying direction corresponding to the new trajectory is determined based on the guide lines in the area. The method includes: if the area is adjacent to a guide line, then: determine the point P2 on the guide line corresponding to the point P1 when any point P1 on the new trajectory is closest to the guide line; determine the tangent direction V1 at point P2; determine the tangent plane S of the laying surface at point P1; project V1 onto S to obtain V2 as the desired laying direction of point P1; if the area is adjacent to two guide lines, then: determine the point P1 on the new trajectory when any point P1 is closest to the guide line; determine the tangent direction V1 at point P2; determine the tangent plane S of the laying surface at point P1; project V1 onto S to obtain V2 as the desired laying direction of point P1; if the area is adjacent to two guide lines, then: determine the point P1 on the new trajectory when any point P1 is closest to the guide line Points P2 and P3 on the guide lines corresponding to when the two guide lines are closest; determining tangent directions V1 and V2 at points P2 and P3; determining a weighted direction V3 of the two guide line directions based on V1 and V2; projecting V3 onto S to obtain a desired placement direction V4 of point P1; and / or, the method of determining the weighted direction V3 of the two guide line directions based on V1 and V2 includes: the weighted direction V3 = d2*V1+d1*V2; where d1 is the distance from point P2 to point P1, and d2 is the distance from point P3 to point P1; If the conditions are met, the new trajectory is determined as the current trajectory. Otherwise, the new trajectory is planned and adjusted according to the desired laying direction, and the adjusted new trajectory is determined as the current trajectory. During the equidistant offset process, the process stops when reaching the boundary of the area or the next guide line, and the trajectory planning of the workpiece to be wire laid is completed based on all the current trajectories obtained.

2. The method for planning fiber placement trajectories for complex curved surfaces according to claim 1, wherein: A closed curve for marking a laying area and / or a window opening area is set on the laying surface of the acquired three-dimensional curved surface model; Wherein, the boundary is: a closed curve of the laying area.

3. The fiber placement trajectory planning method for complex curved surfaces according to claim 1, characterized in that: The method for planning and adjusting the new trajectory according to the desired laying direction includes: The direction of the new track is adjusted to the corresponding desired laying direction, and the distance between the new track and the previous current track is adjusted to minimize the overlap rate and gap rate between the two.

4. The method for planning fiber placement trajectories for complex curved surfaces according to claim 2, wherein: The method for completing trajectory planning of a workpiece to be wire laid based on all obtained current trajectories includes: The obtained current trajectory is divided into a laying area trajectory and a non-laying area trajectory using the closed curve; The segmented current trajectory is discretized into trajectory points, and numerical control machining codes are generated according to the trajectory points.

5. A fiber placement trajectory planning device for a complex curved surface, used in the fiber placement trajectory planning method for a complex curved surface according to claim 1, characterized in that: include: A region segmentation unit is used to obtain a three-dimensional surface model of a workpiece to be wire laid, and to divide the laying surface of the three-dimensional surface model into a plurality of regions by setting a plurality of guide lines; A trajectory determination unit is used to determine the guide line in each area as the current trajectory, perform equidistant offsets on the current trajectory, and determine whether the new trajectory obtained after each equidistant offset meets the corresponding expected placement direction requirements. If so, the new trajectory is determined to be the current trajectory. Otherwise, the new trajectory is planned and adjusted according to the expected placement direction, and the adjusted new trajectory is determined to be the current trajectory. The trajectory planning unit is used to stop when reaching the boundary of the area or the next guide line during the equidistant offset process, and complete the trajectory planning of the workpiece to be wire-laid based on all the current trajectories obtained.

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