3D printing path design and model optimization method and system based on centroid coaxiality

Abstract

The invention discloses a centroid coaxial-based 3D printing path design and model optimization method and system, and the optimization method comprises the steps: carrying out the layering and slicing of a three-dimensional entity model if a printing component has the three-dimensional entity model, and obtaining the printing path information of each printing layer sheet; calculating to obtain the centroid position of the printing layer sheet; the centroid position of the printing layer sheet is judged, and if the centroid is coaxial, the printing path of the printing layer sheet is determined; if the centroids are not coaxial, adjusting the posture of the model until the centroids are coaxial; if the printing component does not have the three-dimensional solid model, designing a first layer of printing layer sheet; the centroid of the first printing layer sheet is calculated, and a centroid shaft is constructed; designing to obtain a printing path of a printing layer sheet; and the determined printing paths of the printing layer sheets are connected, a space printing path of the printing component is constructed, and a three-dimensional entity model of the printing component is obtained. The centroid fluctuation in the printing process is reduced, the stability of the printing process is improved, and the printing success rate is increased.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing construction technology, and in particular to a 3D printing path design and model optimization method and system based on centroid coaxiality. Background Art

[0002] Concrete 3D printing technology has the advantages of fast construction speed, high material utilization rate, low construction cost, etc., and it can also realize the manufacturing of complex-shaped structures. Considering the process principle of 3D printing, which is continuous layering and layer-by-layer stacking, 3D printing concrete materials need to take into account appropriate extrudability and constructability to ensure smooth extrusion molding. Among them, extrudability is a key parameter that reflects whether the concrete material can be smoothly extruded through the printing nozzle and maintain a continuous long strip shape. Constructability refers to the ability of the fresh concrete material to bear the weight of the material and the subsequent overlying printing layer material without obvious deformation and collapse. The two restrict each other, that is, the better the extrudability, the worse the constructability. Since it takes time for the concrete material to form strength after being extruded from the extrusion end during the 3D printing process, if the model is too complex and irregular, or the printing path lacks reasonable design, the printing process will often cause local collapse, overall overturning instability and other printing failures due to insufficient material constructability and insufficient structural stability under the action of the horizontal shear force generated when the extrusion end moves and the weight of the material strip.

[0003] In response to the above phenomenon, many researchers are committed to reducing the probability of failure in the printing process by regulating the properties of concrete materials and process parameters, thereby achieving the effect of improving the success rate of concrete structure printing. However, considering that the rationality of the path design and the model itself are also important factors affecting the printing success rate, the above methods lack solutions from the perspective of printing path design and model optimization. In addition, the current research on printing path design methods is mostly based on improving molding accuracy, efficiency and structural performance, and rarely considers its impact on the printing success rate.

[0004] In view of the above-mentioned prior art problems, considering that the printing and construction of components is a dynamic accumulation process, the center of gravity of the structure will change continuously with the printing process, and the center of gravity position is a major factor affecting the stability of the structure, so its change will have a certain impact on the printing success rate. The centroid refers to the area center of a plane figure or the volume center of a three-dimensional figure, that is, the geometric center of the object. In general, for the theoretical calculation of the center of gravity position of a 3D printed structure, it can be considered that the material is evenly distributed, that is, the center of gravity coincides with the centroid. Therefore, when designing the printing path and optimizing the model, if the centroid position of the printed component is taken into account, the structural stability will be improved and the printing success rate will be further improved. Therefore, it is necessary to develop a printing path design and model optimization method that takes the centroid position into consideration. Summary of the invention

[0005] The purpose of the present invention is to overcome the problems of printing failure such as local collapse, overall overturning and instability caused by insufficient material construction and insufficient structural stability in the prior art, and to provide a 3D printing path design and model optimization method and system based on centroid coaxiality.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A 3D printing path design and model optimization method based on centroid coaxiality includes the following steps:

[0008] S1. Design a printing path according to the design requirements of the printing component to obtain a printing path for the printing layer;

[0009] If the printed component already has a 3D solid model, the printing path design method is as follows:

[0010] S111, slicing the three-dimensional solid model in layers according to the printing layer height to obtain the intersecting contour surface of each slicing plane and the three-dimensional solid model, that is, obtaining the printing path information of each printing layer;

[0011] S112, calculating and obtaining the centroid position of the printed layer;

[0012] S113, judging the centroid position of the printed layer, if the centroids of the printed layer are coaxial, determining the printing path of the printed layer; if the centroids of the printed layer are not coaxial, adjusting the model posture until the centroids of the printed layer are coaxial;

[0013] If the printed component does not have a 3D solid model, the printing path design method is as follows:

[0014] S121, designing the first printing layer according to the design requirements of the printing component;

[0015] S122, calculating the centroid of the first printing layer, and constructing a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction;

[0016] S123, designing a printing path of the printing layer according to the centroid axis and printing component design requirements;

[0017] S2. Connect the determined printing paths of the printing layers to construct a spatial printing path of the printing component and obtain a three-dimensional solid model of the printing component.

[0018] In the above technical scheme, for different components, the printing path design is performed based on the centroid coaxiality to obtain the printing path of the printing layer; for the printing components of the existing 3D solid model, the 3D solid model is sliced ​​in layers according to the printing layer height to obtain the intersection contour surface of each slice plane and the 3D solid model, and the printing path information of each printing layer is further obtained. The centroid position of the printing layer is calculated using the printing path information of the printing layer. The centroid position calculation is performed by some methods or tools, such as Grasshopper, and then the centroid position of the printing layer is judged. If the centroids of each printing layer are coaxial, the printing path of the printing layer can be determined. path; if the centroids of the printed layers are not coaxial, the model is optimized by adjusting the posture of the three-dimensional solid model until the centroids of the printed layers are coaxial; for printed components without a three-dimensional solid model, the first layer of printed layers is designed according to the design requirements of the printed components, and then the centroid of the first layer of printed layers is calculated, and a centroid axis passing through the centroid of the first layer of printed layers and perpendicular to the printing plane is constructed along the printing layer stacking direction; then, according to the centroid axis and the design requirements of the printed components, a printing path of the printed layers is designed; after obtaining the printing path of the printed layers, the printing paths are connected to construct a spatial printing path of the printed components to obtain a three-dimensional solid model of the printed components.

[0019] Through the above technical solution, the main principle is to control the centroid coaxiality of each printed layer of the printed component, realize the spatial path design and component model optimization based on the 3D printing process, solve the problem that the traditional 3D printing spatial path design ignores the impact of the change of the structural center of gravity during the printing process on the stability of the construction process, and effectively reduce the probability of printing failure such as structural overturning and local collapse during the 3D printing construction process using concrete materials. Achieve "centroid coaxial" optimization, reduce the printing failure rate, improve the stability of the printing process, and increase the printing success rate.

[0020] As a preferred embodiment of the present invention, the printing layer height is divided into equal layer thickness printing and unequal layer thickness printing. Equal layer thickness printing means that the printing thickness of each printed layer is the same during the printing process, and unequal layer thickness printing means that there are at least two printed layers in the printed layers with different thicknesses, and the thicknesses of different printed layers are not necessarily the same.

[0021] As a preferred solution of the present invention, a method for calculating the centroid position of a printed layer is implemented based on a Grasshopper plug-in, comprising: deconstructing the three-dimensional solid model according to the thickness of the printed layer to obtain the endpoint coordinates of the deconstructed model, obtaining the coordinate value range of the three-dimensional solid model along the printing layer accumulation direction according to the endpoint coordinates, and calculating the printing height of the three-dimensional solid model;

[0022] According to the printing height data and the printing layer thickness data, the coordinate values ​​of each slice plane along the printing layer stacking direction are calculated and obtained, and the coordinate values ​​of each slice plane along the printing layer stacking direction are used to create a plane perpendicular to the printing layer stacking direction to obtain layered slice plane data;

[0023] Based on the three-dimensional solid model and the layered slicing plane data, the intersection surfaces of each layered slicing plane and the three-dimensional solid model are obtained, and the geometric center position of each intersection surface is obtained as the centroid data of different printing layers.

[0024] As a preferred embodiment of the present invention, the method for calculating the centroid position of the printed layer is specifically implemented as follows: in the Grasshopper environment, according to the thickness of the printed layer, the three-dimensional solid model is deconstructed and identified through the Deconstruct Brep series operators, the coordinates of each endpoint of the three-dimensional solid model are obtained, and then the printing height and the coordinate values ​​of each slicing plane are calculated, and the layered slicing plane is established through the XY Plane and Brep|Plane operators, and the intersection surface of the three-dimensional solid model and the layered slicing plane is solved, and then the geometric center coordinate information of each intersection surface is calculated through the Area operator, and the centroid data of different printed layers is output.

[0025] As a preferred solution of the present invention, adjusting the model posture is to perform structural adjustments on the three-dimensional solid model of the printed component by at least one of rotation, scaling, and translation, specifically adjusting the intersection contour surfaces of each slicing plane and the three-dimensional solid model, so as to adjust the printing path information of the printed layer, so that the centroid of each layer of the printing path can be located on a straight line perpendicular to the printing plane, thereby realizing model optimization based on centroid coaxiality.

[0026] As a preferred embodiment of the present invention, if the printed component already has a three-dimensional solid model, the method for designing the printing path further comprises:

[0027] S114, according to step S113, the printing path of the printing layer is obtained, and the contact area and the suspended range of each printing strip with the previous printing layer are judged layer by layer. If the requirements are met, it means that all printing layers are printable, and the printing path of the printing layer is obtained; if the contact area between each printing strip and the previous printing layer is insufficient or the suspended range is too large, return to step S113 to adjust the model posture until the requirements are met.

[0028] As a preferred solution of the present invention, during the judgment process, the maximum value of the suspended distance of each printing layer does not exceed 1 / 2 of the width of the printing strip to ensure the feasibility of printing.

[0029] As a preferred solution of the present invention, in step S123, the specific implementation method of designing the printing path of the printing layer is: according to the printing layer height and the centroid axis, the outline of the first layer of printing layer is gradually copied along the centroid axis to obtain the printing layer; with the centroid axis as the rotation reference axis, the printing layer is gradually rotated according to the design requirements of the printing component, and the printing layer outline obtained after rotation is the printing path of the printing layer. Through the above technical solution, the design of the printing path of the rotating column with the same cross section can be realized. The rotating column with the same cross section is relatively simple. The printing path can be obtained by copying and rotating the first layer of printing layer; for the column structure with variable cross section, it is necessary to first design a three-dimensional solid model, and then use the above-mentioned method of the existing three-dimensional solid model to design the printing path.

[0030] As a preferred embodiment of the present invention, if the printed component does not have a three-dimensional solid model, the method for printing path design also includes:

[0031] S124, according to step S123, the printing path of the printing layer is obtained, and the contact area and the hanging range between each printing strip and the previous printing layer are judged layer by layer. If the requirements are met, the printing path of the printing layer is obtained; if the contact area between each printing strip and the previous printing layer is insufficient or the hanging range is too large, return to step S121 to redesign the first printing layer until the requirements are met.

[0032] Another aspect of the present invention provides a 3D printing path design and model optimization system based on centroid coaxiality, the system comprising:

[0033] Path design module, including a physical model module and a non-physical model module;

[0034] The solid model module includes a first printing path acquisition module, a centroid calculation module, and a judgment module; the first printing path acquisition module is used to slice the three-dimensional solid model according to the printing layer height to obtain the intersection contour surface of each slice plane and the three-dimensional solid model, that is, to obtain the printing path information of each printing layer; the centroid calculation module is used to calculate the centroid position of the printing layer; the judgment module is used to judge the centroid position of the printing layer, and if the centroids of the printing layers are coaxial, the printing path of the printing layer is determined; if the centroids of the printing layers are not coaxial, the model posture is adjusted until the centroids of the printing layers are coaxial;

[0035] The non-entity model module includes a printing layer design module, a centroid axis acquisition module, and a second printing path acquisition module.

[0036] The printing layer design module is used to design the first printing layer according to the printing component design requirements; the centroid axis acquisition module is used to calculate the centroid of the first printing layer, and construct a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction; the second printing path acquisition module is used to design the printing path of the printing layer according to the centroid axis and the printing component design requirements;

[0037] The connection module is used to connect the determined printing paths of the printing layers, construct a spatial printing path of the printing component, and obtain a three-dimensional solid model of the printing component.

[0038] The present invention also provides an electronic device, comprising at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned 3D printing path design and model optimization method based on centroid coaxiality.

[0039] The present invention also provides a computer-readable storage medium, in which at least one instruction, at least one program, a code set or an instruction set is stored. The at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the above-mentioned 3D printing path design and model optimization method based on centroid coaxiality.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The present invention takes the coaxial centroid control of each printed layer of the printed component as the main principle, realizes the spatial path design and component model optimization based on the 3D printing process, solves the problem that the traditional 3D printing spatial path design ignores the impact of the change of the structural center of gravity during the printing process on the stability of the construction process, and effectively reduces the probability of printing failures such as structural overturning and local collapse during the 3D printing construction process using concrete materials. The "coaxial centroid" optimization is realized, the centroid fluctuation of the structure printing process is reduced, the printing failure rate is reduced, the stability of the printing process is improved, and the printing success rate is increased.

[0042] 2. The present invention considers combining the structural centroid data that changes during the printing process to guide the printing path design and model optimization, and fully plans the changes in the centroid position of the printed layers during the printing process, thereby effectively preventing the collapse of the structure during the printing process, thereby improving the printing success rate of upright printed components with cantilever structures, especially columnar thin-walled structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flow chart of the 3D printing path design and model optimization method based on centroid coaxiality of the present invention;

[0044] Figure 2 Flow chart of the printing path design for printing layers of a hollow cylindrical structure with a variable cross-section with an existing initial model;

[0045] Figure 3 A schematic diagram of printing path information of each printing layer obtained by layered slicing;

[0046] Figure 4 Centroid data for variable cross-section hollow cylindrical structures;

[0047] Figure 5 The centroid data of the variable cross-section hollow column structure is realized by adjusting the model posture to make the centroid coaxial;

[0048] Figure 6 A schematic diagram of the connection of the printing paths for printing layers;

[0049] Figure 7 A three-dimensional solid model of a printed component obtained by the present invention in Example 2;

[0050] Figure 8 A flow chart of the printing path design for printing layers of a printed component without a 3D solid model;

[0051] Fig. 9 It is a schematic diagram showing that the centroid of each printed layer contour is located on the centroid axis (partially);

[0052] Fig.10 The schematic diagram of the printing path design for each layer based on centroid coaxiality;

[0053] Fig.11 It is a schematic diagram of a single complete space printing path with coaxial centroids of layered cross-section profiles;

[0054] Fig.12 Print a 3D model of a component for a thin-walled column. DETAILED DESCRIPTION

[0055] In order to more clearly describe the invention purpose, technical scheme and technical effect advantages in the specific implementation case of the present invention, the scheme in the specific embodiment will be described in detail in combination with the drawings of the specification of the present invention. The specific technical scheme involved in the following specific embodiments is only for a clear and complete description of the innovative technical scheme of the present invention. It is only a part of the specific implementation scheme that can be adopted by the present invention, not all embodiments, and should not be understood as a limitation on the innovative scheme of the present invention. Any scheme adopting the same inventive concept of the present invention should be included in the protection scope of the present invention.

[0056] Secondly, the description of the drawings in the specific embodiments of the present invention is only for the convenience of technical personnel to understand the solution of the present invention. The partial details in the drawings are for the convenience of clearly presenting the technical solution. It should not be considered that all technical features in the drawings must be included in the specific implementation cases, and the detailed features in the drawings should not be identified as additional limitations on the innovative technical solution of the present invention. The components in the various embodiments described and shown in the drawings can be combined and arranged according to different configurations, and these changes in combination and arrangement should be identified as part of the entire embodiment of the innovative solution of the present invention and included in the scope of protection of the present invention.

[0057] In summary, the schemes or descriptions presented in the specific embodiments and drawings of the present invention are not intended to limit the scope of protection claimed, but are merely selected embodiments / cases to help technicians understand the relevant innovative solutions. Based on these embodiments, all other equivalent or parallel embodiments obtained by those skilled in the art without creative work are within the scope of protection claimed by the present invention.

[0058] Example 1

[0059] This embodiment provides a 3D printing path design and model optimization method based on centroid coaxiality, such as Figure 1 As shown, the following steps are included:

[0060] S1. Design a printing path according to the design requirements of the printing component to obtain a printing path for the printing layer;

[0061] If the printed component already has a 3D solid model, the printing path design method is as follows:

[0062] S111, slicing the three-dimensional solid model in layers according to the printing layer height to obtain the intersecting contour surface of each slicing plane and the three-dimensional solid model, that is, obtaining the printing path information of each printing layer;

[0063] S112, calculating and obtaining the centroid position of the printed layer;

[0064] S113, judging the centroid position of the printed layer, if the centroids of the printed layer are coaxial, determining the printing path of the printed layer; if the centroids of the printed layer are not coaxial, adjusting the model posture until the centroids of the printed layer are coaxial;

[0065] If the printed component does not have a 3D solid model, the printing path design method is as follows:

[0066] S121, designing the first printing layer according to the design requirements of the printing component;

[0067] S122, calculating the centroid of the first printing layer, and constructing a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction;

[0068] S123, designing a printing path for printing layers according to the requirements of the centroid axis and the printing component design;

[0069] S4. Connect the determined printing paths of the printing layers, construct a spatial printing path of the printing component, and obtain a three-dimensional solid model of the printing component.

[0070] Example 2

[0071] This embodiment adopts the method of embodiment 1, and realizes the 3D printing path design and model optimization of the variable cross-section hollow cylindrical structure of the existing initial model based on the centroid coaxiality, such as Figure 2 As shown, the following steps are included:

[0072] First, design the printing path:

[0073] S111. According to the printing layer height parameters required by the printed component design, the initial model of the variable cross-section hollow cylindrical structure is sliced ​​in layers to obtain the intersection contour surface of each slice plane and the three-dimensional solid model, that is, the printing path information of each printed layer is obtained.

[0074] It should be noted that the printing layer height is divided into equal layer thickness printing and unequal layer thickness printing. Equal layer thickness printing means that the printing thickness of each printed layer is the same during the printing process, and unequal layer height printing means that the thickness of different printed layers is not necessarily the same, that is, there are at least two layers of printed layers with different thicknesses. The variable cross-section hollow columnar structure in this embodiment is formed by the transition from a rectangular cross-section to a trapezoidal cross-section. It is printed with equal layer thickness, each layer height is 10mm, and the total height of the column is 2200mm. In this embodiment, the wall thickness of the designed printing component is equal to the width of the printing strip, and the contour of each layer is the printing path information of the corresponding printing layer, such as Figure 3 In the present invention, the slicing planes of the printed components are parallel to the printing platform. The slicing planes are the planes where the layers of the printed components are located. The printing platform refers to the plane where the overall structure is located during the printing operation.

[0075] S112, using the three-dimensional solid model to calculate the centroid position of the printed layer.

[0076] In the theoretical calculation process, the printed structure is assumed to be an object with uniform material mass distribution, and the center of gravity is the centroid (geometric center). The centroid data of each printed layer refers to the centroid coordinate data of the intersection of each layered slice plane and the designed printed structure model.

[0077] Specifically, the method for calculating the centroid position of the printed layer can be implemented based on the Grasshopper plug-in, and the specific implementation method is: according to the printing layer thickness, the three-dimensional solid model is deconstructed to obtain the endpoint coordinates of the deconstructed model, and the coordinate value range of the three-dimensional solid model along the printing layer stacking direction is obtained according to the endpoint coordinates, and the printing height of the three-dimensional solid model is calculated; according to the printing height data and the printing layer thickness data, the coordinate values ​​of each slicing plane along the printing layer stacking direction are calculated, and the coordinate values ​​of each slicing plane along the printing layer stacking direction are used to create a plane perpendicular to the printing layer stacking direction to obtain layered slicing plane data; based on the three-dimensional solid model and the layered slicing plane data, the intersection surfaces of each layered slicing plane and the three-dimensional solid model are obtained, and the geometric center position of each intersection surface is obtained as the centroid data of different printed layers.

[0078] An XYZ coordinate system is established for the three-dimensional solid model, where the length direction of the printed component is the X-axis direction, the width direction of the printed component is the Y-axis direction, the height direction of the printed component is the Z-axis direction, the XY plane is the printing plane, and the printing layer direction is the Z-axis direction. The endpoint refers to the corner point of the three-dimensional solid model. The coordinate value of each layered slice plane along the printing layer direction is the Z-axis coordinate value.

[0079] The acquisition process is as follows: in the Grasshopper environment, according to the thickness of the printing layer, the 3D solid model is deconstructed and identified through the Deconstruct Brep series operators, the coordinates of each endpoint of the 3D solid model are obtained, and then the printing height and the coordinate values ​​of each slicing plane are calculated. The layered slicing plane is established through the XYPlane and Brep|Plane operators, and the intersection of the 3D solid model and the layered slicing plane is solved. Then, the geometric center coordinate information of each intersection surface is calculated through the Area operator, and the centroid data of different printing layers is output.

[0080] Through the above method, a series of centroid data points (x i ,y i ,z i ), and the centroid data of the variable cross-section hollow column structure is obtained as Figure 4 As shown, the 10mm division is too dense to be easy to understand, so Figure 4 A schematic diagram showing the 100mm layers is shown in FIG.

[0081] S113, judging the centroid position of the printed layers, if the centroids of the printed layers are coaxial, determining the printing path of the printed components; if the centroids of the printed layers are not coaxial, adjusting the model posture until the centroids of the printed layers are coaxial. Figure 4The centroid data is used to judge. It can be seen that the centroid positions are not on a straight line, which means that the centroids of the layers are not coaxial. Then the model posture is adjusted until the centroids of the printed layers are coaxial.

[0082] Adjusting the model posture is to adjust the structure of the three-dimensional solid model of the printed component by at least one of rotation, scaling, and translation. Specifically, the intersection contour surface of each slice plane and the three-dimensional solid model is adjusted to adjust the printing path information of each printing layer so that the centroid of each layer printing path can be located on a straight line perpendicular to the printing plane, thereby realizing the model optimization based on centroid coaxiality. In this embodiment, the centroids of the printing paths of all printing layers are located on the same straight line by translation. Figure 5 As shown, the straight line is along the Z-axis direction and perpendicular to the printing plane (XY plane), which is the centroid axis. The contour surface of each layer obtained after the centroid coaxial adjustment is the printing path information of the corresponding printing layer.

[0083] In some embodiments, the method of printing path design further comprises:

[0084] S114, according to step S113, the printing path of the printing layer is obtained, and the contact area and the suspended range of each printing strip with the previous printing layer are judged layer by layer. If the requirements are met, it means that all printing layers are feasible for printing, and the printing path of the printing layer is obtained; if the contact area of ​​each printing strip with the previous printing layer is insufficient or the suspended range is too large, return to step S113 to adjust the model posture until the requirements are met. During the judgment process, the maximum suspended distance of each printing layer does not exceed 1 / 2 of the width of the printing strip to ensure printing feasibility.

[0085] S2, connect the determined printing paths of the printing layers, construct the spatial printing path of the printing component, and obtain a three-dimensional solid model of the printing component. Figure 6 As shown, in this embodiment, the corner points of the rectangular / trapezoidal cross-section of the variable-section hollow columnar structure are used as the layer-by-layer connection points, which can avoid the appearance of breakpoints on the surface of the variable-section hollow columnar structure caused by the connection points, and help to ensure the printing quality and beautiful appearance. There is no restriction in the actual design process, and you can choose according to your design and printing needs.

[0086] Based on the contour shapes of each layer generated by S1, the three-dimensional solid model of the printed component is generated by lofting and adjusting the model posture. While retaining the original appearance design requirements such as rotation and transition, the model optimization based on centroid coaxiality is realized, such as Figure 7 That is, under the premise of meeting the design requirements, the fluctuation of the centroid position during the printing process is reduced and the structural stability of the printing process is improved.

[0087] For upright variable-section hollow cylindrical structures with existing initial models, a printing path design and model optimization method based on centroid coaxiality is proposed based on modeling-slicing-path design. The centroids of each layered section are controlled to be coaxial by adjusting the model posture, thereby adjusting the spatial path and generating an optimized model. This can reduce the centroid fluctuation of the structure printing process while retaining the appearance design requirements of the initial model, thereby improving the structural stability of the printing process and the printing success rate.

[0088] Example 3

[0089] This embodiment adopts the method of Embodiment 1. For printed components without three-dimensional solid models, the conventional solid modeling and slicing steps are skipped, and the spatial printing path design and model design are directly performed according to the needs. Taking the hollow cylindrical structure without an initial model as an example, the 3D printing path design based on centroid coaxiality is realized, and an XYZ coordinate system is established for the hollow cylindrical structure, wherein the length direction of the printed component is the X-axis direction, the width direction of the printed component is the Y-axis direction, the height direction of the printed component is the Z-axis direction, the XY plane is the printing plane, and the printing layer stacking direction is the Z-axis direction.

[0090] like Figure 8 As shown, the method comprises the following steps:

[0091] To design the printing path:

[0092] S121, design the first printing layer according to the design requirements of the printing component. In this embodiment, the design is a rotating column with a trapezoidal cross section, and the wall thickness of the printing component is equal to the width of the printing strip, then the single layer contour is the printing path information of the corresponding layer.

[0093] S122, calculating the centroid of the first printing layer, and constructing a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane (XY plane) along the printing layer stacking direction (Z axis direction);

[0094] S123, according to the printing layer height and the centroid axis, gradually copy the outline of the first printing layer along the centroid axis to obtain the printing layer; take the centroid axis as the rotation reference axis, gradually rotate the printing layer according to the design requirements of the printing component, and the printing layer outline obtained after rotation is the printing path of the printing layer.

[0095] Determine the printing layer height information according to the printing requirements. The printing layer height is the height position of each printing layer along the molding direction (Z-axis direction). With the printing layer height as the spacing, gradually copy the outline of the first printing layer from bottom to top along the centroid axis; through the above-mentioned centroid axis-based copying, ensure that the centroids of each printing layer are located on the centroid axis, and ensure that the centroids of each printing layer are coaxial. This example is a uniform layer height printing, each layer height is 10mm, the total height of the column is 2200mm, and the centroids of the outlines of each printing layer are located on the centroid axis (partially). Fig. 9 In this embodiment, the last printed layer is rotated 30° compared to the first printed layer, and then rotated evenly layer by layer, as shown below. Fig.10 shown.

[0096] In some embodiments, the printing path of the printing layer is obtained according to step S123, and the contact area and the suspended range of each printing strip with the previous printing layer are judged layer by layer. If the requirements are met, the printing path of the printing layer is obtained; if the contact area of ​​each printing strip with the previous printing layer is insufficient or the suspended range is too large, return to step S121 to redesign the first printing layer until the requirements are met. It should be noted that the adjustment of the printing layer in this step needs to ensure that the maximum suspended distance of each printing layer does not exceed 1 / 2 of the width of the printing strip to ensure printing feasibility.

[0097] S2, connect the determined printing paths of the printing layers, construct the spatial printing path of the printing component, and obtain a three-dimensional solid model of the printing component. Fig.11 As shown in the figure, in this embodiment, the corner points of the trapezoidal cross section are used as the connection points for each layer, which can avoid the appearance of breakpoints on the surface of the column caused by the connection points, which helps to ensure the printing quality and beautiful appearance. There is no restriction in the actual design process, and you can choose it according to the design and printing requirements. Based on the contour shape of each layer generated by S1, the three-dimensional solid model of the printed component is generated by lofting to complete the model design based on the coaxial shape of the centroid, as shown below Fig.12 shown.

[0098] For upright rotating column structures with the same cross section that do not have a solid three-dimensional model, the paths of each layered section are designed based on the principle of centroid coaxiality, and then the spatial printing path and three-dimensional model are generated. In the 3D printing path design stage, the structural stability of the printing process can be directly guaranteed from the structure itself through the method of centroid coaxiality of each layer. An unconventional path design process is adopted, and the solid model modeling and slicing links in the conventional process (modeling-slicing-path design) are omitted for path design, which saves processes and computing power and simplifies the process. At the same time, the errors of the path and the solid model in the traditional slicing process are avoided from the source, effectively improving the printing completion of the digital model.

[0099] Example 4

[0100] This embodiment provides a 3D printing path design and model optimization system based on centroid coaxiality, the system comprising:

[0101] Path design module, including a physical model module and a non-physical model module;

[0102] The solid model module includes a first printing path acquisition module, a centroid calculation module, and a judgment module; the first printing path acquisition module is used to slice the three-dimensional solid model according to the printing layer height, and obtain the intersection contour surface of each slice plane and the three-dimensional solid model, that is, to obtain the printing path information of each printing layer; the centroid calculation module is used to calculate the centroid position of the printing layer; the judgment module is used to judge the centroid position of the printing layer, and if the centroids of the printing layers are coaxial, the printing path of the printing layer is determined; if the centroids of the printing layers are not coaxial, the model posture is adjusted until the centroids of the printing layers are coaxial;

[0103] The non-entity model module includes a printing layer design module, a centroid axis acquisition module, and a second printing path acquisition module.

[0104] The printing layer design module is used to design the first printing layer according to the design requirements of the printing component; the centroid axis acquisition module is used to calculate the centroid of the first printing layer, and construct a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction; the second printing path acquisition module is used to design a printing path for the printing layer according to the centroid axis and the design requirements of the printing component;

[0105] The connection module is used to connect the printing paths of the determined printing layers, construct the spatial printing path of the printing component, and obtain the three-dimensional solid model of the printing component.

[0106] The systems or modules described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. Of course, when implementing this application, the functions of each module can be implemented in the same or multiple software and / or hardware, or the module that implements the same function can be implemented by a combination of multiple sub-modules.

[0107] This embodiment also provides an electronic device, including at least one processor, a memory connected to the at least one processor, and at least one input / output interface connected to the at least one processor; the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor, so that the at least one processor can execute the 3D printing path design and model optimization method based on centroid coaxiality of the aforementioned embodiment 1. The input / output interface may include a display, a keyboard, a mouse, and a USB interface for inputting and outputting data.

[0108] The electronic device can be an electronic device used for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute a 3D printing path design and model optimization method based on centroid coaxiality of Example 1.

[0109] Those skilled in the art can understand that: all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), disks or optical disks, etc. Various media that can store program codes.

[0110] When the above-mentioned integrated unit of the present invention is implemented in the form of a software functional unit and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present invention can be essentially or partly reflected in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0111] This embodiment also provides a computer-readable storage medium, which stores at least one instruction, at least one program, code set or instruction set. The at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement the above-mentioned 3D printing path design and model optimization method based on centroid coaxiality.

[0112] Computer readable storage media can be tangible devices that hold and store instructions used by instruction execution devices. Computer readable storage media can be, for example, but not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any combination thereof.

[0113] For those skilled in the art, when understanding the solutions described in the specific embodiments of the present invention, they can refer to the conventional technical manuals in the field. At the same time, for the places where the above-mentioned terms appear, they can make appropriate understandings or adjustments for reference, and deduce the implementation of the same or similar technical solutions without paying any creative work.

[0114] The above embodiments describe only the basic principles, main features and / or advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and the invention content of the specification only describe the principles or specific cases of the present invention. Without departing from the essence of the innovative idea of ​​the present invention, the innovative scheme of the present invention may be subject to various changes and improvements, and these changes and improvements all fall within the scope of protection required by the present invention.

Claims

1. A 3D printing path design and model optimization method based on centroid coaxiality, characterized in that: The following steps are involved: S1. Design a printing path according to the design requirements of the printing component to obtain a printing path for the printing layer; If the printed component already has a 3D solid model, the printing path design method is as follows: S111, slicing the three-dimensional solid model in layers according to the printing layer height to obtain the intersecting contour surface of each slicing plane and the three-dimensional solid model, that is, obtaining the printing path information of each printing layer; S112, calculating and obtaining the centroid position of the printed layer; S113, judging the centroid position of the printed layer, if the centroids of the printed layer are coaxial, determining the printing path of the printed layer; if the centroids of the printed layer are not coaxial, adjusting the model posture until the centroids of the printed layer are coaxial; If the printed component does not have a 3D solid model, the printing path design method is as follows: S121, designing the first printing layer according to the design requirements of the printing component; S122, calculating the centroid of the first printing layer, and constructing a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction; S123, designing a printing path of the printing layer according to the centroid axis and printing component design requirements; S2. Connect the determined printing paths of the printing layers to construct a spatial printing path of the printing component and obtain a three-dimensional solid model of the printing component.

2. The 3D printing path design and model optimization method based on centroid coaxiality according to claim 1 is characterized in that: The method for calculating the centroid position of the printed layer is implemented based on the Grasshopper plug-in, including: deconstructing the three-dimensional solid model according to the thickness of the printed layer to obtain the endpoint coordinates of the deconstructed model, obtaining the coordinate value range of the three-dimensional solid model along the printing layer accumulation direction according to the endpoint coordinates, and calculating the printing height of the three-dimensional solid model; According to the printing height data and the printing layer thickness data, the coordinate values ​​of each slice plane along the printing layer stacking direction are calculated and obtained, and the coordinate values ​​of each slice plane along the printing layer stacking direction are used to create a plane perpendicular to the printing layer stacking direction to obtain layered slice plane data; Based on the three-dimensional solid model and the layered slicing plane data, the intersection surfaces of each layered slicing plane and the three-dimensional solid model are obtained, and the geometric center position of each intersection surface is obtained as the centroid data of different printing layers.

3. The 3D printing path design and model optimization method based on centroid coaxiality according to claim 2 is characterized in that: The calculation method of the centroid position of the printed layer is specifically implemented as follows: in the Grasshopper environment, according to the thickness of the printed layer, the three-dimensional solid model is deconstructed and identified through the Deconstruct Brep series operators, the coordinates of each endpoint of the three-dimensional solid model are obtained, and then the printing height and the coordinate values ​​of each slicing plane are calculated, and the layered slicing plane is established through the XY Plane and Brep|Plane operators, and the intersection surface of the three-dimensional solid model and the layered slicing plane is solved, and then the geometric center coordinate information of each intersection surface is calculated through the Area operator, and the centroid data of different printed layers is output.

4. The centroid-coaxial 3D printing path design and model optimization method according to claim 1, characterized in that: Adjusting the model posture is to adjust the structure of the three-dimensional solid model of the printed component by at least one of rotation, scaling, and translation, specifically adjusting the intersection contour surface of each slice plane and the three-dimensional solid model, so as to adjust the printing path information of the printed layer, so that the centroid of each layer of the printing path can be located on a straight line perpendicular to the printing plane, thereby realizing model optimization based on centroid coaxiality.

5. The centroid-coaxial 3D printing path design and model optimization method according to any one of claims 1 to 4, characterized in that: If the printed component already has a 3D solid model, the printing path design method also includes: S114, according to step S113, the printing path of the printing layer is obtained, and the contact area and the suspended range of each printing strip with the previous printing layer are judged layer by layer. If the requirements are met, it means that all printing layers are printable, and the printing path of the printing layer is obtained; if the contact area between each printing strip and the previous printing layer is insufficient or the suspended range is too large, return to step S113 to adjust the model posture until the requirements are met.

6. The centroid-coaxial 3D printing path design and model optimization method according to claim 5, characterized in that: During the determination process, the maximum suspension distance of each printed layer does not exceed 1 / 2 of the width of the printed strip to ensure printing feasibility.

7. The centroid-coaxial 3D printing path design and model optimization method according to claim 1, characterized in that: In step S123, the specific implementation method of designing the printing path of the printing layer is: according to the printing layer height and the centroid axis, the outline of the first printing layer is gradually copied along the centroid axis to obtain the printing layer; with the centroid axis as the rotation reference axis, the printing layer is gradually rotated according to the printing component design requirements, and the printing layer outline obtained after rotation is the printing path of the printing layer.

8. The centroid-coaxial 3D printing path design and model optimization method according to claim 1 or 7, characterized in that: If the printed component does not have a 3D solid model, the printing path design method also includes: S124, according to step S123, the printing path of the printing layer is obtained, and the contact area and the hanging range between each printing strip and the previous printing layer are judged layer by layer. If the requirements are met, the printing path of the printing layer is obtained; if the contact area between each printing strip and the previous printing layer is insufficient or the hanging range is too large, return to step S121 to redesign the first printing layer until the requirements are met.

9. A 3D printing path design and model optimization system based on centroid coaxiality, characterized in that: The system comprises: Path design module, including a physical model module and a non-physical model module; The solid model module includes a first printing path acquisition module, a centroid calculation module, and a judgment module; the first printing path acquisition module is used to slice the three-dimensional solid model according to the printing layer height, and obtain the intersection contour surface of each slice plane and the three-dimensional solid model, that is, to obtain the printing path information of each printing layer; the centroid calculation module is used to calculate the centroid position of the printing layer; the judgment module is used to judge the centroid position of the printing layer, and if the centroids of the printing layers are coaxial, the printing path of the printing layer is determined; if the centroids of the printing layers are not coaxial, the model posture is adjusted until the centroids of the printing layers are coaxial; The non-entity model module includes a printing layer design module, a centroid axis acquisition module, and a second printing path acquisition module. The printing layer design module is used to design the first printing layer according to the printing component design requirements; the centroid axis acquisition module is used to calculate the centroid of the first printing layer, and construct a centroid axis passing through the centroid of the first printing layer and perpendicular to the printing plane along the printing layer stacking direction; the second printing path acquisition module is used to design the printing path of the printing layer according to the centroid axis and the printing component design requirements; The connection module is used to connect the determined printing paths of the printing layers, construct a spatial printing path of the printing component, and obtain a three-dimensional solid model of the printing component.

10. An electronic device comprising at least one processor and a memory in communication with the at least one processor; the memory stores instructions executable by the at least one processor, characterized in that: The instructions are executed by the at least one processor so that the at least one processor can execute the above-mentioned 3D printing path design and model optimization method based on centroid coaxiality.

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