Printing path planning methods, apparatus, equipment, and storage media

Abstract

This application discloses a printing path planning method, apparatus, device, and storage medium, belonging to the field of printing path planning technology. The method includes: acquiring a surface layer of a surface to be printed; processing the surface layer using a median coordinate plane parameterization method to obtain a parameterized plane of a homeomorphic disk; connecting all vertices on the boundary line of the parameterized plane to a target vertex to obtain at least one connecting line; the target vertex being a point in the parameterized plane corresponding to the geodesic center point; dividing all the connecting lines equally based on the number of paths to obtain at least one dividing point for each connecting line; determining the projection point of each dividing point on the surface to be printed; and generating a printing path based on the projection points. This application can solve the problem of poor surface quality and mechanical properties of printed parts.

Description

Technical Field

[0001] This application relates to the field of print path planning, and more particularly to a print path planning method, apparatus, device, and storage medium. Background Technology

[0002] In 3D printing technology, a five-axis printer is created by adding two rotation axes to the printing platform of a traditional 3D printer. Based on the shape and structural features of the part's surface, it performs surface layering and path planning to achieve conformal printing. During path planning, to ensure uniform filament output as the nozzle moves in three-dimensional space, contour lines are typically drawn based on the geodesic distance of the surface. Connecting these contour lines forms the nozzle's printing path, resulting in paths with equal widths.

[0003] However, when the curved surface layer has irregular shape or non-rounded boundary lines, forcing the path planning of the curved surface with the requirement of equal width will result in problems such as path distortion or large gaps between the path corners and other paths, which will lead to poor surface quality and mechanical properties of the printed parts. Summary of the Invention

[0004] The main objective of this application is to provide a printing path planning method, apparatus, device, and storage medium, which aims to solve the technical problem of poor surface quality and mechanical properties of printed parts.

[0005] To achieve the above objectives, this application provides a method for printing path planning, comprising:

[0006] Obtain a surface layer sheet of the surface to be printed; wherein, the surface layer sheet is an irregular surface composed of multiple triangular facets; the surface layer sheet has a geodesic center point;

[0007] The surface layer is processed using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk;

[0008] Connect all vertices on the boundary line between the target vertex and the parameterized plane to obtain at least one connecting line; the target vertex is the point in the parameterized plane corresponding to the geodesic center point;

[0009] Based on the number of paths, all the connecting lines are divided equally to obtain at least one dividing point for each connecting line.

[0010] Determine the projection points of each of the aforementioned division points on the surface to be printed;

[0011] A printing path is generated based on the projection points.

[0012] Optionally, determining the projection points of each of the equally divided points on the surface to be printed includes:

[0013] Determine the target triangular facets on the parameterized plane where each of the aforementioned division points is located;

[0014] Based on the area value of the triangular facet containing the dividing point and the area values ​​of multiple sub-triangles of the triangular facet, an area ratio factor is determined; wherein, the sub-triangles are the three sub-triangles formed by the dividing point and the three sides of the triangular facet containing the dividing point.

[0015] Based on the three-dimensional coordinates of the three vertices of the target triangular facet on the surface to be printed, the area scaling factor of the three sub-triangles, and Formula 1, the projection point of the division point on the surface to be printed is determined.

[0016] Formula 1 is: s = a1·p1 + a2·p2 + a3·p3;

[0017] Wherein, s represents the projection point of the dividing point onto the surface to be printed, p1 is the three-dimensional coordinate point of the first vertex of the triangular facet containing the dividing point onto the surface to be printed, p2 is the three-dimensional coordinate point of the second vertex of the triangular facet containing the dividing point onto the surface to be printed, p3 is the three-dimensional coordinate point of the third vertex of the triangular facet containing the dividing point onto the surface to be printed, a1 is the area ratio factor of the sub-triangle formed by the dividing point, the second vertex, and the third vertex, a2 is the area ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the third vertex, and a3 is the area ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

[0018] Optionally, determining the area scaling factor based on the area value of the triangular facet containing the dividing point and the area values ​​of multiple sub-triangles of the triangular facet includes:

[0019] Based on the first vertex, the second vertex, the third vertex, and Formula 2, determine the area value of the triangular facet containing the dividing point;

[0020] Based on the area value, the dividing point, the second vertex, the third vertex, and Formula 3, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the second vertex, and the third vertex;

[0021] Based on the area value, the dividing point, the first vertex, the third vertex, and Formula 4, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the third vertex;

[0022] Based on the area value, the dividing point, the first vertex, the second vertex, and Formula 5, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the second vertex;

[0023] Formula 2 is: Where a is the area of ​​the triangular facet containing the dividing point, q1 is the first vertex, q2 is the second vertex, and q3 is the third vertex;

[0024] Formula 3 is: Where a1 is the area ratio factor of the sub-triangle formed by the dividing point, the second vertex and the third vertex, and p is the dividing point;

[0025] Formula four is: Where a2 is the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex and the third vertex;

[0026] Formula 5 is: Where a3 is the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

[0027] Optionally, generating the printing path based on the projection point includes:

[0028] Number all equally divided points on the same connecting line to obtain at least one sequence of equally divided points;

[0029] Connect the projection points corresponding to two adjacent odd-numbered division points with the same number in all the division point sequences to obtain the odd-numbered printable sub-path;

[0030] The printing path is obtained by connecting the tail vertex and the head vertex of two adjacent printing sub-paths.

[0031] Optionally, after generating the printing path based on the projection point, the method further includes:

[0032] The current printing sub-path is determined from the aforementioned printing sub-path;

[0033] Determine the first projection point in the current printing sub-path, and the second and third projection points corresponding to the two even-numbered points adjacent to the first projection point on the same connection line.

[0034] Based on the spatial coordinate information of the first projection point, the spatial coordinate information of the second projection point, the spatial coordinate information of the third projection point, and Formula Six, the printing width of the first projection point in the printing sub-path is determined.

[0035] Formula 6 includes: ω i =|S i-1 S i |+|S i S i+1 |,

[0036] Where, ω i S represents the printing width of the first projection point in the printing sub-path. i S represents the first projection point. i-1 Indicates the second projection point, S i+1 This refers to the third projection point.

[0037] Optionally, after obtaining the surface layer of the surface to be printed, the method further includes:

[0038] Extract the boundary lines of the curved surface layer;

[0039] Determine the geodesic distances from the vertices of all the triangular facets in the curved surface layer to the boundary line;

[0040] The vertex corresponding to the maximum value among all the geodesic distances is taken as the geodesic center point.

[0041] Optionally, the step of processing the surface layer using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk includes:

[0042] Extract the feature boundaries of the surface layer;

[0043] The feature boundary is projected onto the disk boundary in proportion to the arc length to obtain the initial disk.

[0044] The median coordinate method is used to calculate the weights of all vertices in the surface layer on the surface layer.

[0045] Based on the weights corresponding to each vertex, the vertices are mapped onto the initial disk to obtain the parameterized plane.

[0046] Secondly, this application provides a printing path planning device, the printing path planning device comprising:

[0047] An acquisition module is used to acquire a surface layer sheet of the surface to be printed; wherein, the surface layer sheet is an irregular surface composed of multiple triangular facets; the surface layer sheet has a geodesic center point;

[0048] The first processing module is used to process the curved surface layer using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk.

[0049] A connection module is used to connect all vertices on the boundary line of the target vertex and the parameterized plane to obtain at least one connection line; the target vertex is the point in the parameterized plane corresponding to the geodesic center point;

[0050] The second processing module is used to divide all the connecting lines equally based on the number of paths, so as to obtain at least one dividing point for each connecting line.

[0051] The determination module is used to determine the projection points of each of the equal division points on the surface to be printed;

[0052] The generation module is used to generate a printing path based on the projection points.

[0053] Thirdly, this application provides a print path planning device, including: a processor, a memory, and a print path planning program stored in the memory, wherein the print path planning program is executed by the processor to implement the steps of the print path planning method described in any of the above claims.

[0054] Fourthly, this application provides a computer-readable storage medium storing a printing path planning program, which, when executed by a processor, implements the printing path planning method as described in any of the preceding claims.

[0055] This application proposes a printing path planning method. During printing path planning, the connecting lines in a parameterized plane are equally divided to obtain at least one dividing point for each connecting line. The projection points of these dividing points onto the surface to be printed are further determined. Finally, a printing path is generated for all projection points. Since the lengths of the connecting lines in the parameterized plane are not different, the positions of the dividing points of different connecting lines are not the same, and the projection points of these dividing points on the surface to be printed are also different. Therefore, when generating a printing path based on all projection points, there is no limitation on the width of the printing path. Compared to related technologies that use equal-width path planning methods to generate printing paths, i.e., generating printing paths based on a specific width, this application avoids problems such as path distortion or large gaps at path corners and other paths that occur under equal-width limitations. This results in smoother lines, fuller internal filling, and ultimately solves the problem of poor surface quality and mechanical properties of the printed parts. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the printing path planning device used in this application;

[0057] Figure 2 This is a flowchart illustrating the first embodiment of the printing path planning method of this application;

[0058] Figure 3 This is a schematic diagram of the geodesic center point in the curved layer of this application;

[0059] Figure 4 This is a schematic diagram of the parameterized plane of the disk homeomorphism of this application;

[0060] Figure 5 This is a schematic diagram of the connecting lines between the target vertex and the boundary line of the parameterized plane in this application, and all vertices therein.

[0061] Figure 6 This is a schematic diagram of the printing path for this application;

[0062] Figure 7 This is a schematic diagram showing the positional relationship between the first projection point, the second projection point, and the third projection point in this application.

[0063] Figure 8 This is a schematic diagram of the functional modules of the first embodiment of the printing path planning device of this application.

[0064] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0065] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0066] Traditional planar 3D printing typically uses a planar layering method, planning the path for each layer to form the printing nozzle path. The printing process involves stacking layers, resulting in a "step effect" in the printed parts. This leads to poor surface quality, and thin-walled structures are prone to cracking between layers, causing anisotropy in mechanical properties. Curved surface printing is an important cutting-edge research direction in additive manufacturing. By adding two rotation axes to the printing platform of a traditional 3D printer, a five-axis printer is created. Based on the shape and structural characteristics of the part's surface, curved surface layering and curved path planning are performed, enabling conformal printing. Compared to planar printing, curved surface printing can alleviate or eliminate the "step effect," reduce or eliminate support structures, and significantly improve the mechanical properties of the parts.

[0067] Compared to planar path planning, surface path planning involves a three-dimensional problem, increasing the algorithm's complexity. To more accurately describe the nozzle path width on a curved surface, existing surface path planning methods typically use geodesic distance instead of Euclidean distance to calculate the distances between path points. Geodesic distance represents the shortest distance traveled along the surface between two points, making it more suitable for measuring distances on a curved surface. To ensure uniform filament output as the nozzle moves in three-dimensional space, existing surface path planning algorithms usually draw contour lines based on the geodesic distance of the surface, connecting these contour lines to form the nozzle's printing path, achieving a consistent path width. Currently, surface path planning mainly forms a ring path pattern that contracts inward from the surface boundary and a strip path pattern with parallel lines arranged in one direction. However, from the perspective of path planning effect, there are still problems with the equal width surface path planning. When the surface layer has an irregular shape or the boundary line is not rounded, forcing the surface to be path planned with the requirement of equal width will result in problems such as path distortion or large gaps between the path corners and other paths, which will lead to poor surface quality and mechanical properties of the printed parts.

[0068] This application provides a solution that, during print path planning, divides the connecting lines in a parametric plane into equal parts, obtaining at least one division point for each connecting line. Furthermore, it determines the projection points of these division points onto the surface to be printed. Finally, a print path is generated for all projection points. Since the lengths of the connecting lines in the parametric plane are not different, the positions of the division points for different connecting lines are not the same, and the projection points of these division points onto the surface to be printed are also different. Therefore, when generating the print path based on all projection points, there is no limitation on the print path width. Compared to related technologies that use equal-width path planning methods to generate print paths, i.e., generating print paths based on a specific width, this application avoids problems such as path distortion or large gaps at path corners compared to equal-width limitations. This results in smoother lines, fuller internal filling, and ultimately solves the problem of poor surface quality and mechanical properties of the printed parts.

[0069] Reference Figure 1 , Figure 1 This is a schematic diagram of the printing path planning device for the hardware operating environment involved in the embodiments of this application.

[0070] like Figure 1As shown, the printing path planning device may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen and an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed random access memory (RAM) or a stable non-volatile memory (NVM), such as a disk drive. The memory 1005 may also optionally be a storage device independent of the aforementioned processor 1001.

[0071] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the printing path planning device and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0072] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a data storage module, a network communication module, a user interface module, and a print path planning program.

[0073] exist Figure 1 In the printed path planning device shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the printed path planning device of this application can be set in the printed path planning device. The printed path planning device calls the printed path planning program stored in the memory 1005 through the processor 1001 and executes the printed path planning method provided in the embodiment of this application.

[0074] Based on, but not limited to, the hardware structure of the printing path planning device described above, this application provides a first embodiment of a printing path planning method. (Refer to...) Figure 2 , Figure 2 A flowchart illustrating the first embodiment of the printing path planning method of this application is shown.

[0075] It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0076] In this embodiment, the printing path planning method includes:

[0077] Step S10: Obtain the surface layer of the surface to be printed.

[0078] The curved surface layer is an irregular curved surface composed of multiple triangular facets; the curved surface layer has a geodesic center point.

[0079] It should be noted that the main body executing the printing path planning method is the printing path planning device, which stores a printing path planning program. When the printing path planning device executes the printing path planning program, it executes the printing path planning method of this embodiment.

[0080] Specifically, the surface layer of the surface to be printed can be stored locally on the printing path planning device or in the cloud. When step S10 is executed, the printing path planning device can directly call the surface layer of the surface to be printed from the local device or the cloud.

[0081] In this embodiment, the boundary line of the curved layer is used as the reference line with a geodesic distance of zero. The vertex corresponding to the maximum value of all vertices in the curved layer to the boundary line is the geodesic center point, which is to determine the geodesic center point of the curved layer. Therefore, to determine the geodesic center point of the curved layer, as an optional implementation, after step S10, the following is further included:

[0082] Step S11: Extract the boundary lines of the curved surface layer.

[0083] Step S12: Determine the geodesic distance from the vertices of all the triangular facets in the curved surface layer to the boundary line.

[0084] Step S13: Take the vertex corresponding to the maximum value among all the geodesic distances as the geodesic center point.

[0085] Specifically, all triangular facets in the curved surface layer are identified, that is, the triangular facets that constitute the curved surface layer. The triangular side of a certain facet where there is no adjacent triangular facet is taken as the boundary line of the curved surface layer, and this boundary line is taken as the reference line where the geodesic distance is zero.

[0086] After extracting the boundary lines of the surface layer, the geodesic distance field of the surface layer can be calculated using the FastMarching method. The FastMarching method is a classic geodesic distance calculation method that can quickly calculate the geodesic distance between all vertices on the triangular mesh and the multi-source point. That is, the geodesic distance between the vertices of all triangular faces on the surface layer and the boundary lines can be calculated using the FastMarching method.

[0087] Furthermore, after calculating the geodesic distances from the vertices of all triangular faces on the curved surface to the boundary line, all geodesic distances are traversed to determine the maximum value. Finally, the vertex corresponding to the maximum value is taken as the geodesic center point, and the vertex index of the geodesic center point is recorded. (Reference) Figure 3 As shown, Figure 3 A schematic diagram of the geodesic center point of the curved surface layer.

[0088] Step S20: Using the median coordinate plane parameterization method, the surface layer is processed to obtain the parameterized plane of the homeomorphic disk.

[0089] In this embodiment, to ensure that the curved surface layer and the parameterized plane have the same shape, topology, and one-to-one index relationship, further, as an optional implementation, step S20 specifically includes:

[0090] Step S201: Extract the feature boundaries of the curved surface layer.

[0091] Step S201: Project the feature boundary onto the disk boundary in proportion to the arc length to obtain the initial disk.

[0092] Step S203: Calculate the weights of all vertices in the surface layer on the surface layer using the median coordinate method.

[0093] Step S204: Based on the weights corresponding to each vertex, map the vertices onto the initial disk to obtain the parameterized plane.

[0094] Specifically, to ensure that the boundaries of the curved surface layer can be correctly mapped onto the disk and that the shape and length of the boundaries remain unchanged, the feature boundaries of the curved surface layer can be projected and fixed onto the boundary of the homeomorphic disk in proportion to the arc length, that is, the feature boundaries are projected onto the disk boundary in proportion to the arc length to obtain the initial disk.

[0095] Furthermore, after obtaining the initial disk, to ensure that the parametric plane and the surface layer have the same mesh topology and that the parametric plane has a shape similar to the original surface, the median coordinate method can be used to calculate the weight values ​​of the vertices of each triangular facet within the surface layer on the surface layer. That is, the median coordinate method is used to calculate the weights of all vertices in the surface layer on the surface layer, and based on the weights of each vertex, the vertices are mapped onto the initial disk to obtain the parametric plane, as shown below. Figure 4 As shown.

[0096] Finally, after mapping each vertex onto the initial disk according to its weight, a one-to-one index relationship between the spatial coordinates and UV coordinates of each vertex on the surface layer can be established. That is, the vertex on the parameterized plane corresponding to the surface layer is represented by its UV coordinates. The UV coordinates are two-dimensional coordinates with a value range of [0,1], used to represent the position parameters of the vertex on the plane.

[0097] Step S30: Connect all vertices on the boundary line of the target vertex and the parameterized plane to obtain at least one connecting line.

[0098] The target vertex is the point in the parameterized plane that corresponds to the geodesic center point.

[0099] Specifically, based on the index relationship between the spatial coordinate points and UV coordinate points of the aforementioned curved surface layer, the target vertex corresponding to the geodesic center point can be determined from the parametric plane, and the target vertex can be used as the starting point of the connecting line.

[0100] After identifying the target vertex from the parametric plane, boundary extraction algorithms such as boundary tracing can be used to identify the boundary lines of the parametric plane and extract all boundary vertices on the boundary. After extracting all boundary vertices on the boundary lines, all boundary vertices need to be sorted to ensure that they are stored in an ordered manner, either clockwise or counterclockwise. That is, any boundary vertex is selected as the starting point for sorting, and then the sorting is performed along the boundary edges connected to it until the starting point is reached, and the boundary vertices are stored in a clockwise direction.

[0101] Furthermore, after determining all boundary vertices and the target vertex, the boundary vertices on the parameterized plane's boundary line can be used as the endpoints of connecting lines. Following the order of the boundary vertices, the starting point and each endpoint are connected to obtain the set of connecting lines from the target vertex to the boundary line, such as... Figure 5 As shown, the connecting lines are sorted and stored according to the storage order of the boundary vertices.

[0102] Step S40: Based on the number of paths, divide all the connecting lines equally to obtain at least one dividing point for each connecting line.

[0103] In this embodiment, the number of paths can be a preset number of surface paths, or it can be a number of surface paths set according to actual needs.

[0104] Specifically, the number of paths can be stored locally on the printing path planning device or in the cloud. When step S40 is executed, the number of paths can be retrieved directly from the local storage or the cloud. After retrieving the number of paths, all connecting lines can be divided equally according to the number of paths to obtain at least one division point for each connecting line.

[0105] It should be noted that when dividing all connecting lines equally using the number of paths, the number of division points can be set to twice the number of paths to facilitate a more accurate estimation of the width of the printed path later.

[0106] Step S50: Determine the projection points of each of the equal division points on the surface to be printed.

[0107] In this embodiment, to accurately determine the projection points of each division point on the surface to be printed, further, as an optional implementation, step S50 specifically includes:

[0108] Step S501: Determine the target triangular facet on the parameterized plane where each of the equal division points is located.

[0109] Step S502: Determine the area ratio factor based on the area value of the triangular facet where the dividing point is located and the area values ​​of the multiple sub-triangles of the triangular facet.

[0110] The sub-triangles are the three sub-triangles formed by the dividing point and the three sides of the triangular facet containing the dividing point.

[0111] In this embodiment, a triangular facet containing equally divided points can be used as the target triangular facet.

[0112] Specifically, for each target triangular facet containing a dividing point, the facet can be divided into three sub-triangles by using the three vertices and the dividing point. Then, by calculating the area of ​​these three sub-triangles and the area of ​​the facet, the area ratio factor of each sub-triangle can be determined.

[0113] For example, the area of ​​the triangular facet containing the dividing point can be determined based on the first vertex, the second vertex, the third vertex, and Formula 2. Based on the area value, the dividing point, the second vertex, the third vertex, and Formula 3, the area ratio factor corresponding to the sub-triangle formed by the dividing point, the second vertex, and the third vertex can be determined. Based on the area value, the dividing point, the first vertex, the third vertex, and Formula 4, the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the third vertex can be determined. Based on the area value, the dividing point, the first vertex, the second vertex, and Formula 5, the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the second vertex can be determined.

[0114] Formula 2 is: Where a is the area of ​​the triangular facet containing the dividing point, q1 is the first vertex, q2 is the second vertex, and q3 is the third vertex;

[0115] Formula 3 is: Where a1 is the area ratio factor of the sub-triangle formed by the dividing point, the second vertex and the third vertex, and p is the dividing point;

[0116] Formula four is: Where a2 is the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex and the third vertex;

[0117] Formula 5 is: Where a3 is the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

[0118] Traverse and process all the division points, and extract the UV coordinates of the three endpoints of the target triangular facet where the division point is located. The division point can be denoted as p, and the three vertices can be denoted as q1, q2 and q3 respectively. Then, the area ratio factor of the large triangle (triangular facet) occupied by the three sub-triangles formed by point p and the three sides of the triangular facet can be calculated by the above formula. This area ratio factor can be used to represent the positional relationship between p and q1, q2 and q3.

[0119] Step S503: Based on the three-dimensional coordinates of the three vertices of the target triangular facet on the surface to be printed, the area scaling factor of the three sub-triangles, and Formula 1, determine the projection point of the division point on the surface to be printed.

[0120] Formula 1 is: s = a1·p1 + a2·p2 + a3·p3;

[0121] Wherein, s represents the projection point of the dividing point onto the surface to be printed, p1 is the three-dimensional coordinate point of the first vertex of the triangular facet containing the dividing point onto the surface to be printed, p2 is the three-dimensional coordinate point of the second vertex of the triangular facet containing the dividing point onto the surface to be printed, p3 is the three-dimensional coordinate point of the third vertex of the triangular facet containing the dividing point onto the surface to be printed, a1 is the area ratio factor of the sub-triangle formed by the dividing point, the second vertex, and the third vertex, a2 is the area ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the third vertex, and a3 is the area ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

[0122] Specifically, based on the aforementioned index information, the three-dimensional coordinates of the three vertices on the surface to be printed can be obtained. The three-dimensional coordinates can be denoted as p1, p2 and p3 respectively. Combining the positional relationship (area ratio factor) between the dividing point and the three vertices, the three-dimensional spatial coordinates s of the dividing point on the surface to be printed can be calculated by performing linear interpolation calculation on the surface to be printed using the above formula 1.

[0123] Step S60: Generate a printing path based on the projection points.

[0124] In this embodiment, after determining the projection points of each division point on the surface to be printed, the projection points corresponding to the division points with the same number can be used as path vertices, and the path vertices can be connected to obtain the printing path.

[0125] It should be noted that, based on the foregoing, the number of equal division points in each connecting line is twice the number of paths. That is, the number of projection points corresponding to the equal division points of each connecting line is twice the number of paths. Therefore, if all projection points are connected, the actual number of printed paths obtained is twice the preset number of paths. Thus, to ensure that the number of actual printed paths obtained subsequently is consistent with the preset number of paths, further, as an optional implementation, step S60 specifically includes:

[0126] Step S601: Number all the equally divided points in the same connecting line to obtain at least one sequence of equally divided points.

[0127] Step S602: Connect the projection points corresponding to two adjacent odd-numbered division points with the same number in all the division point sequences to obtain the odd-numbered printable sub-path.

[0128] Step S603: Connect the tail vertices and head vertices of two adjacent printed sub-paths to obtain the printed path.

[0129] Specifically, based on the above, after dividing each connecting line into equal parts and obtaining the division points of each connecting line, the division points of each connecting line can be sorted according to the order of the connecting lines, from the end point to the starting point, to obtain the sequence of division points of each connecting line.

[0130] Furthermore, after determining the projection points of all the equally divided points on the surface to be printed, since there is a one-to-one correspondence between the projection points and the equally divided points, the projection points corresponding to all equally divided points with odd numbers can be used as path vertices. Connecting adjacent path vertices with the same number yields the odd-numbered printing sub-paths. (Refer to...) Figure 6 As shown.

[0131] Finally, the tail vertex of the adjacent preceding printing sub-path is connected to the head vertex of the following printing sub-path to obtain the printing path. It is understood that, after obtaining the printing path, when printing according to the printing path, to ensure printing accuracy and print quality, as an optional implementation, after step S60, the following further step is included:

[0132] Step S61: Determine the current printing sub-path from the printing sub-path.

[0133] Step S62: Determine the first projection point in the current printing sub-path, as well as the second and third projection points corresponding to the two even-numbered points adjacent to the first projection point on the same connecting line.

[0134] Step S63: Based on the spatial coordinate information of the first projection point, the spatial coordinate information of the second projection point, the spatial coordinate information of the third projection point, and Formula 6, determine the printing width of the first projection point in the printing sub-path.

[0135] Formula 6 includes: ω i =|S i-1 S i |+|S i S i+1 |,

[0136] Where, ω i S represents the printing width of the first projection point in the printing sub-path. i S represents the first projection point. i-1 Indicates the second projection point, S i+1 This refers to the third projection point.

[0137] Specifically, refer to Figure 7As shown, we can assume that the current printing sub-path is the i-th printing sub-path. We can determine the set of even-numbered vertices adjacent to the i-th printing sub-path as the (i-1)-th and (i+1)-th reference points. Furthermore, we can identify the S-th reference point in the i-th printing sub-path. i The projection points corresponding to the S equal division points are taken as the first projection point, and the first projection point is taken as the path vertex, and connected with the Sth equal division point. i The first projection point corresponding to each of the S equal division points, the second projection point and the third projection point corresponding to two adjacent even-numbered equal division points on the same connecting line, i.e., the Sth... i-1 The projection point corresponding to the S equal division point is the second projection point, and the Sth projection point is the second projection point. i+1 The projection point corresponding to each of the three equally divided points is the third projection point.

[0138] After determining the first projection point S i Second projection point S i-1 and the third projection point S i+1 Then, based on the first projection point S i Spatial coordinate information, second projection point S i-1 Spatial coordinate information and third projection point S i+1 Using the spatial coordinate information, calculate the first projection point S. i With the second projection point S i-1 The first distance between them, and the first projection point S i With the third projection point S i+1 The second distance between them is used as the sum of the first distance and the second distance, which is then used as the width of the first projection point in the printing sub-path. That is, the printing width of the first projection point in the printing sub-path is determined based on the spatial coordinate information of the first projection point, the spatial coordinate information of the second projection point, the spatial coordinate information of the third projection point, and Formula 6.

[0139] In this embodiment, the path vertex is obtained from the first projection point based on the equally divided points. By mixing the distances between the first projection point and the second and third projection points respectively, the width of the path vertex of the current printing sub-path can be estimated, that is, the printing width of the first projection point. Since the path vertex has the characteristics of varying width within the path and locally equal width within the path, the difficulty of filament control in 3D printers can be reduced.

[0140] In this embodiment, a surface layer of the surface to be printed is obtained; wherein the surface layer is an irregular surface composed of multiple triangular facets; the surface layer has a geodesic center point; the surface layer is processed using the median coordinate plane parameterization method to obtain a parameterized plane of a homeomorphic disk; all vertices on the boundary line between the target vertex and the parameterized plane are connected to obtain at least one connecting line; the target vertex is a point in the parameterized plane corresponding to the geodesic center point; based on the number of paths, all the connecting lines are equally divided to obtain at least one dividing point for each connecting line; the projection points of each dividing point on the surface to be printed are determined; and a printing path is generated based on the projection points. This embodiment can solve the problem of poor surface quality and mechanical properties of printed parts.

[0141] In the printing path planning process, the connecting lines in the parametric plane are equally divided to obtain at least one dividing point for each connecting line. The projection points of these dividing points onto the surface to be printed are then determined. Finally, the printing path is generated based on these projection points. Since the lengths of the connecting lines in the parametric plane are not uniform, the positions of the dividing points on different connecting lines are not identical, and the projection points of these dividing points onto the surface to be printed are also different. Therefore, the printing path generated based on all projection points does not impose a limitation on its width. Compared to related technologies that use equal-width path planning methods to generate printing paths (i.e., generating printing paths based on a specific width), this application avoids problems such as path distortion or large gaps at path corners compared to equal-width limitations. This results in smoother lines, fuller internal filling, and ultimately solves the problem of poor surface quality and mechanical properties of the printed parts.

[0142] In addition, the printing path in this embodiment is characterized by a shrinking pattern from the boundary towards the center point of the curved surface. Although the boundary line of the printing path is not regular and smooth, the sub-path can also quickly converge into a circle or ellipse. After the sub-path shrinks, it will become shorter and shorter, and the path vertices will become more dense. The shrinking of the sub-path into a circle or ellipse is more conducive to nozzle movement and filament control.

[0143] Based on the same concept, this application proposes a printing path planning device, referring to... Figure 8 , Figure 8 This is a schematic diagram of the functional modules of the printing path planning device of this application.

[0144] This printing path planning device includes:

[0145] An acquisition module is used to acquire a surface layer sheet of the surface to be printed; wherein, the surface layer sheet is an irregular surface composed of multiple triangular facets; the surface layer sheet has a geodesic center point;

[0146] The first processing module is used to process the curved surface layer using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk.

[0147] A connection module is used to connect all vertices on the boundary line of the target vertex and the parameterized plane to obtain at least one connection line; the target vertex is the point in the parameterized plane corresponding to the geodesic center point;

[0148] The second processing module is used to divide all the connecting lines equally based on the number of paths, so as to obtain at least one dividing point for each connecting line.

[0149] The determination module is used to determine the projection points of each of the equal division points on the surface to be printed;

[0150] The generation module is used to generate a printing path based on the projection points.

[0151] It should be noted that the printing path planning device can also be equipped with more modules. The various embodiments of the printing path planning device in this embodiment and their achieved technical effects can be referred to the various implementation methods of the printing path planning method in the foregoing embodiments, and will not be repeated here.

[0152] Furthermore, embodiments of this application also propose a computer storage medium storing a printing path planning program. When executed by a processor, the printing path planning program implements the steps of the printing path planning method described above. Therefore, it will not be repeated here. Additionally, the beneficial effects of using the same method will not be repeated here either. For technical details not disclosed in the computer-readable storage medium embodiments of this application, please refer to the description of the method embodiments of this application. As an example, program instructions can be deployed to execute on a single computing device, or on multiple computing devices located at one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0153] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0154] It should also be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided in this application, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0155] Through the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware, or it can be implemented by special-purpose hardware including application-specific integrated circuits, special-purpose CPUs, special-purpose memory, special-purpose components, etc. Generally, any function performed by a computer program can be easily implemented by corresponding hardware, and the specific hardware structure used to implement the same function can also be diverse, such as analog circuits, digital circuits, or special-purpose circuits. However, for this application, software program implementation is more often the preferred implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium, such as a computer floppy disk, USB flash drive, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of this application.

[0156] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for printing path planning, characterized in that, The method includes: Obtain a surface layer sheet of the surface to be printed; wherein, the surface layer sheet is an irregular surface composed of multiple triangular facets; the surface layer sheet has a geodesic center point; The surface layer is processed using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk; Connect all vertices on the boundary line between the target vertex and the parameterized plane to obtain at least one connecting line; the target vertex is the point in the parameterized plane corresponding to the geodesic center point; Based on the number of paths, all the connecting lines are divided equally to obtain at least one dividing point for each connecting line. Determine the projection points of each of the aforementioned division points onto the surface to be printed; Based on the projection points, a printing path is generated; The determination of the projection points of each of the equally divided points on the surface to be printed includes: Determine the target triangular facets on the parameterized plane where each of the aforementioned division points is located; Based on the area value of the triangular facet containing the dividing point and the area values ​​of multiple sub-triangles of the triangular facet, an area ratio factor is determined; wherein, the sub-triangles are the three sub-triangles formed by the dividing point and the three sides of the triangular facet containing the dividing point. Based on the three-dimensional coordinates of the three vertices of the target triangular facet on the surface to be printed, the area scaling factor of the three sub-triangles, and Formula 1, the projection point of the division point on the surface to be printed is determined. Formula 1 is: ; in, This indicates the projection points of the equal division points onto the surface to be printed. The first vertex of the triangular facet containing the dividing point is located at the three-dimensional coordinate point corresponding to the surface to be printed. The second vertex of the triangular facet containing the dividing point is located at the three-dimensional coordinate point corresponding to the surface to be printed. Let the third vertex of the triangular facet containing the dividing point be the three-dimensional coordinate point corresponding to the surface to be printed. The area scaling factor is the area of ​​the sub-triangle formed by the dividing point, the second vertex, and the third vertex. The area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the third vertex. The area ratio factor is the ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

2. The printing path planning method according to claim 1, characterized in that, The determination of the area scaling factor based on the area value of the triangular facet containing the dividing point and the area values ​​of multiple sub-triangles of the triangular facet includes: Based on the first vertex, the second vertex, the third vertex, and Formula 2, determine the area value of the triangular facet containing the dividing point; Based on the area value, the dividing point, the second vertex, the third vertex, and Formula 3, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the second vertex, and the third vertex; Based on the area value, the dividing point, the first vertex, the third vertex, and Formula 4, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the third vertex; Based on the area value, the dividing point, the first vertex, the second vertex, and Formula 5, determine the area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the second vertex; Formula 2 is: a = ;in, Let be the area of ​​the triangular facet containing the points of division. For the first vertex, The second vertex, The third vertex; Formula 3 is: ;in, The area scaling factor is the area of ​​the sub-triangle formed by the dividing point, the second vertex, and the third vertex. The points are the equal division points; Formula four is: ;in, The area ratio factor corresponding to the sub-triangle formed by the dividing point, the first vertex, and the third vertex; Formula 5 is: ;in, The area ratio factor is the ratio factor of the sub-triangle formed by the dividing point, the first vertex, and the second vertex.

3. The printing path planning method according to claim 1, characterized in that, The step of generating a printing path based on the projection point includes: Number all equally divided points on the same connecting line to obtain at least one sequence of equally divided points; Connect the projection points corresponding to two adjacent odd-numbered division points with the same number in all the division point sequences to obtain the odd-numbered printable sub-path; The printing path is obtained by connecting the tail vertex and the head vertex of two adjacent printing sub-paths.

4. The printing path planning method according to claim 3, characterized in that, After generating the printing path based on the projection point, the method further includes: The current printing sub-path is determined from the aforementioned printing sub-path; Determine the first projection point in the current printing sub-path, and the second and third projection points corresponding to the two even-numbered points adjacent to the first projection point on the same connection line. Based on the spatial coordinate information of the first projection point, the spatial coordinate information of the second projection point, the spatial coordinate information of the third projection point, and Formula Six, the printing width of the first projection point in the printing sub-path is determined. Formula 6 includes: , in, This represents the printing width of the first projection point in the printing sub-path. Represents the first projection point. Indicates the second projection point, This refers to the third projection point.

5. The printing path planning method according to claim 1, characterized in that, After obtaining the surface layer of the surface to be printed, the method further includes: Extract the boundary lines of the curved surface layer; Determine the geodesic distances from the vertices of all the triangular facets in the curved surface layer to the boundary line; The vertex corresponding to the maximum value among all the geodesic distances is taken as the geodesic center point.

6. The printing path planning method according to claim 1, characterized in that, The method of using median coordinate plane parameterization to process the curved surface layer to obtain the parameterized plane of the homeomorphic disk includes: Extract the feature boundaries of the surface layer; The feature boundary is projected onto the disk boundary in proportion to the arc length to obtain the initial disk. The median coordinate method is used to calculate the weights of all vertices in the surface layer on the surface layer. Based on the weights corresponding to each vertex, the vertices are mapped onto the initial disk to obtain the parameterized plane.

7. A printing path planning device, characterized in that, The printing path planning device includes: An acquisition module is used to acquire a surface layer sheet of the surface to be printed; wherein, the surface layer sheet is an irregular surface composed of multiple triangular facets; the surface layer sheet has a geodesic center point; The first processing module is used to process the curved surface layer using the median coordinate plane parameterization method to obtain the parameterized plane of the homeomorphic disk. A connection module is used to connect all vertices on the boundary line of the target vertex and the parameterized plane to obtain at least one connection line; the target vertex is the point in the parameterized plane corresponding to the geodesic center point; The second processing module is used to divide all the connecting lines equally based on the number of paths, so as to obtain at least one dividing point for each connecting line. The determining module is used to determine the projection points of each of the equal division points on the surface to be printed; A generation module is used to generate a printing path based on the projection points; The printing path planning device is used to implement the steps of the printing path planning method as described in any one of claims 1 to 6.

8. A printing path planning device, characterized in that, include: A processor, a memory, and a print path planning program stored in the memory, the print path planning program being executed by the processor to implement the steps of the print path planning method as claimed in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a print path planning program, which, when executed by a processor, implements the print path planning method as described in any one of claims 1 to 6.

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