Path planning method and device for non-entity support of parts, equipment and medium

Abstract

The invention discloses a path planning method and device for non-entity support of parts, equipment and a medium, relates to the technical field of additive manufacturing, and aims to solve the problems that the data volume of a slice contour point set for non-entity support of existing parts is large, and the number of times of switching-off and switching-off is large during printing. The method comprises the following steps: acquiring a three-dimensional model and a slice thickness of a non-entity support of a part; according to the slice thickness, extracting intersecting line segments of each triangular patch and each slice plane in the three-dimensional model to obtain a data set; performing duplicate removal and sorting processing on points in the data set to obtain a first slice contour set; deleting collinear data points meeting a preset collinear condition in the first slice contour set to obtain a second slice contour set; and performing gap filling on the second slice contour set by adopting an open contour stitching algorithm to obtain a third slice contour set. The path planning method for the non-entity support of the part is used for reducing the data volume of the section contour point set for the non-entity support of the part and reducing the number of times of printing light interruption.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and particularly relates to a path planning method, device, equipment and medium for non-solid supports of parts. Background Technique

[0002] Laser Deposition Melting (LDM) technology is an organic combination of rapid prototyping technology and laser cladding technology. It uses metal powder as raw material and high-energy laser as heat source. According to the scanning path planned by the layer slicing information of the CAD model of the formed part, the conveyed metal powder is melted layer by layer, rapidly solidified, and deposited layer by layer, so as to realize the direct manufacturing of the whole part. STL format (short for Stereo Lithography) is an interface protocol developed by 3D Systems in 1988 and is a 3D graphic file format serving rapid prototyping technology. The STL file consists of a series of unordered triangular faces. The definition of each triangular face includes vertex coordinates and the normal vector of the triangular face. Due to its simplicity and low error rate, STL has become the most commonly used file format and the de facto interface standard in the field of rapid prototyping technology. Currently, almost all 3D printers on the market print by recognizing STL models.

[0003] For some parts with overhangs, non-solid supports need to be added to ensure that the parts do not collapse and deform. Currently, after slicing the non-solid supports to obtain a set of sliced contour points, the printing path is directly generated for printing. However, the directly formed set of sliced contour points not only has a large amount of data and occupies memory, resulting in a slow reading speed of the printing device, but also there will be many unconnected line segments within a certain distance in the printing path, leading to a large number of disconnections during the printing process.

[0004] Therefore, there is an urgent need for a path planning method, device, equipment and medium for non-solid supports of parts. Summary of the Invention

[0005] The purpose of the present invention is to provide a path planning method, device, equipment and medium for non-solid supports of parts, which is used to solve the problems that the data volume of the set of sliced contour points for generating non-solid supports of parts is large and there will be a large number of disconnections during printing.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a path planning method for non-solid supports of parts, including obtaining a three-dimensional model of the non-solid support of the part and the slice thickness; the three-dimensional model is composed of unordered triangular patches;

[0008] Extract the intersection line segments of each triangular facet in the 3D model with each slice plane according to the slice thickness to obtain a data set;

[0009] Deduplicate the points in the data set, and sort the points in the deduplicated data set using the interpolation method to obtain the first slice contour set;

[0010] Delete the collinear data points in the first slice contour set that meet the preset collinear condition to obtain the second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than the preset vector angle;

[0011] Use the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set; the third slice contour set is used to generate the non-solid support printing path of the part.

[0012] Compared with the prior art, the path planning method for non-solid support of parts provided by the present invention includes obtaining the 3D model of the non-solid support of the part and the slice thickness; extracting the intersection line segments of each triangular facet in the 3D model with each slice plane according to the slice thickness to obtain a data set; in this solution, the points in the data set are deduplicated, and then the points in the deduplicated data set are sorted using the interpolation method to obtain the first slice contour set; the collinear data points in the first slice contour set that meet the preset collinear condition are deleted to obtain the second slice contour set, which greatly reduces the amount of contour point set data, reduces the storage and transmission overhead of slice data, and at the same time removes some unnecessary points, which can reduce the pause of the laser during the printing process, make the printed lines smooth, and reduce the consumption of consumables; use the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set; filling and stitching the disconnected line segments can reduce the total laser jump length, reduce the number of breaks, and improve the laser printing efficiency and quality.

[0013] In a second aspect, the present invention also provides a path planning device for non-solid support of parts, including a 3D model acquisition module for acquiring the 3D model of the non-solid support of the part and the slice thickness; the 3D model is composed of disordered triangular facets;

[0014] An intersection line segment extraction module for extracting the intersection line segments of each triangular facet in the 3D model with each slice plane according to the slice thickness to obtain a data set;

[0015] A deduplication and sorting module for deduplicating the points in the data set and sorting the points in the deduplicated data set using the interpolation method to obtain the first slice contour set;

[0016] A data point deletion module that meets the preset collinearity condition is used to delete collinear data points in the first slice contour set that meet the preset collinearity condition, and obtain a second slice contour set; the preset collinearity condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than a preset vector angle;

[0017] A void filling module is used to fill the voids in the second slice contour set by using an open contour stitching algorithm to obtain a third slice contour set; the third slice contour set is used to generate a printing path for the non-solid support of the part.

[0018] In a third aspect, the present invention provides a path planning device for non-solid support of a part, including:

[0019] A communication unit / communication interface is used to obtain a three-dimensional model of the non-solid support of the part and the slice thickness; the three-dimensional model is composed of unordered triangular patches;

[0020] A processing unit / processor extracts the intersection line segments of each triangular patch in the three-dimensional model with each slice plane according to the slice thickness to obtain a data set;

[0021] Deduplicate the points in the data set, and sort the points in the deduplicated data set by using the interpolation method to obtain a first slice contour set;

[0022] Delete collinear data points in the first slice contour set that meet the preset collinearity condition to obtain a second slice contour set; the preset collinearity condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than a preset vector angle;

[0023] Use an open contour stitching algorithm to fill the voids in the second slice contour set to obtain a third slice contour set; the third slice contour set is used to generate a printing path for the non-solid support of the part.

[0024] In a fourth aspect, the present invention provides a computer-readable storage medium, in which instructions are stored, and when the instructions are run, the above-mentioned path planning method for non-solid support of a part is implemented.

[0025] The technical effects achieved by the device type solution provided in the second aspect, the device type solution provided in the third aspect, and the computer-readable storage medium type solution provided in the fourth aspect are the same as those of the method type solution provided in the first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0027] Figure 1 Flowchart of a path planning method for non - physical support of parts provided by the present invention;

[0028] Figure 2 Schematic diagram of the intersection of the slicing plane and triangular facets provided by the present invention;

[0029] Figure 3 Schematic diagram of removing collinear data points of the first type provided by the present invention;

[0030] Figure 4 Schematic diagram of removing collinear data points of the second type provided by the present invention;

[0031] Figure 5 Schematic diagram of void filling provided by the present invention;

[0032] Figure 6 Schematic diagram of removing closed contours provided by the present invention;

[0033] Figure 7 Schematic diagram of the structure of a path planning device for non - physical support of parts provided by the present invention;

[0034] Figure 8 Schematic diagram of the structure of a path planning device for non - physical support of parts provided by the present invention. Detailed implementation manners<�

[0035] In order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. For example, the first threshold and the second threshold are only used to distinguish different thresholds, and do not limit their sequence. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different.

[0036] It should be noted that in the present invention, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly, using words such as "exemplary" or "for example" is intended to present related concepts in a specific manner.

[0037] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the relationship between related objects and indicates that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. "At least one (item)" or a similar expression thereof refers to any combination of these items, including any combination of single item or plural items. For example, at least one (item) of a, b, or c can mean: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c, where a, b, and c can be single or multiple.

[0038] During the laser deposition manufacturing process of parts, for parts with complex structures, overhangs, and large sizes, appropriate non-solid supports need to be added to ensure that the parts do not collapse or deform. Currently, after obtaining the contour point set by slicing the non-solid support, no processing is performed. Due to the complex structure and large size, the sliced contour data point set will contain a large number of duplicate, collinear, and void data points. This not only results in a large amount of data, limiting the data storage and transmission speed, but also easily leads to rough surfaces, large consumption of consumables, and frequent light interruption during printing, affecting the printing efficiency and quality.

[0039] To solve the above problems, the present invention provides a path planning method, device, equipment, and medium for the non-solid support of parts, which processes the sliced contour of the non-solid support of the part, reduces the data volume of the contour point set, reduces the number of light interruptions, and improves the laser printing efficiency and quality. The following will be described in conjunction with the accompanying drawings.

[0040] Figure 1 It is a flowchart of a path planning method for the non-solid support of parts provided by the present invention; as Figure 1 shown, the method includes the following steps:

[0041] Step 101: Obtain the three-dimensional model and slicing thickness of the non-solid support of the part;

[0042] The three-dimensional model is an stl format file. The three-dimensional model in stl format consists of a series of unordered triangular patches, and each triangular patch includes vertex coordinates and the normal vector of the triangular surface. The slicing thickness of the non-solid support is the same as that of the part. The slicing thickness is the distance between two adjacent slicing planes.

[0043] Step 102: Extract the intersection line segments of each triangular patch in the three-dimensional model with each slicing plane according to the slicing thickness to obtain a data set;

[0044] As an alternative approach, first, determine the height of each slicing plane based on the slicing thickness and the height of the non-solid support of the part;

[0045] Specifically, determine the number of slicing layers according to the result of dividing the height of the non-solid support of the part by the slicing thickness;

[0046] Multiply the number of layers of each slicing plane by the slicing thickness to obtain the height of each slicing plane; for example, the height of the first slicing plane is one slicing thickness, and the height of the second slicing plane is two slicing thicknesses.

[0047] For any slicing plane, traverse each triangular facet, and determine the target triangular facets that intersect with the current slicing plane as the triangular facets that meet any one of the height preset conditions;

[0048] Specifically, refer to Figure 2 , assuming that the three vertices of one of the triangular facets are p0(x0, y0, z0), p1(x1, y1, z1), p3(x3, y3, z3), obtain the minimum height minz and the maximum height maxz among p0, p1, p3. If the minimum height minz is greater than the height of the slicing plane, or the maximum height is less than the height of the slicing plane, then this triangular facet does not intersect with the slicing plane. If the triangular facet intersects with the slicing plane, the intersecting line segment formed by their intersection points is the slicing contour. If there are any that meet the following height preset conditions, it means the triangular facet and the slicing plane intersect. The height preset conditions are as follows:

[0049] P0.z < z && p1.z >= z && p2.z >= z

[0050] P0.z > z && p1.z < z && p2.z < z

[0051] P1.z < z && p0.z >= z && p2.z >= z

[0052] P1.z > z && p0.z < z && p2.z < z

[0053] P2.z < z && p1.z >= z && p0.z >= z

[0054] P2.z > z && p1.z < z && p0.z < z

[0055] Among them, P0.z is the height of the first vertex of the triangular facet, p1.z is the height of the second vertex of the triangular facet, p2.z is the height of the third vertex of the triangular facet, and z is the height of the current slicing plane;

[0056] Extract the intersecting line segments of the target triangular facets and the current slicing plane to obtain the slicing contour set corresponding to the current slicing plane;

[0057] Extract all the intersecting line segments corresponding to the layer slices to obtain a dataset. Store the extracted intersecting line segments in Polygons in the form of a data structure; the stored data structure is as follows:

[0058] Struct Segment

[0059] {

[0060] Point start;

[0061] Point end;

[0062] };

[0063] vector <point>Polygon;

[0064] Vector <polygon>Polygons;

[0065] Step 103: Remove duplicates from the points in the dataset, and sort the points in the dataset after duplicate removal using interpolation to obtain the first slice contour set;

[0066] In this step, duplicate removal and sorting are performed on each point in the slice contour to obtain an ordered set of slice contour points; specifically, first traverse the line segments in the dataset, remove the line segments where the starting point and the ending point coincide, and obtain the dataset after duplicate removal;

[0067] Traverse the line segments in the dataset after duplicate removal, and compare the current line segment with the points in the dataset after duplicate removal. If the coordinates of the starting point of the current line segment are equal to the coordinates of a certain point in the dataset after duplicate removal, and this point is denoted as the target starting point, then insert the ending point of the current line segment after the target starting point in the dataset after duplicate removal to obtain the first slice contour set; the target starting point is the point that coincides with the starting point of the current line segment;

[0068] Or, if the coordinates of the ending point of the current line segment are equal to the coordinates of a certain point in the dataset after duplicate removal, denote this point as the target ending point, and insert the starting point of the current line segment before the target ending point in the dataset after duplicate removal to obtain the first slice contour set, where the target ending point is the point that coincides with the ending point of the current line segment;

[0069] Or, if no point with the same coordinates as the starting point or the ending point of the current line segment is found in the dataset after duplicate removal, then traverse all the line segments in the dataset after duplicate removal to find the line segment with the shortest distance to the current line segment, denoted as the target line segment. If the target line segment is before the current line segment, insert the current line segment after the target line segment; if the target line segment is after the current line segment, then insert the current line segment before the target line segment to obtain the first slice contour set; the target line segment is the line segment with the shortest distance to the current line segment.

[0070] Step 104: Delete the collinear data points in the first slice contour set that meet the preset collinear condition to obtain the second slice contour set;

[0071] The preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments among the line segments formed by the data points is less than the preset vector angle;

[0072] Specifically, traverse the data points in the first slice contour set, determine the multiple data points that form a straight line, delete all the data points except the endpoints in the formed straight line, and connect the endpoints of the straight line; as Figure 3 shown, if three data points form a straight line, then delete the data point in the middle of the two endpoints to obtain a straight line formed only by the two endpoints.

[0073] Determine multiple data points that make up the target polyline, delete the points of the target polyline except the endpoints, and connect the endpoints of the target polyline to obtain a second slice contour set; the angle between adjacent line segments in the target polyline is less than a preset vector angle. As Figure 4 shown, 6 data points form a polyline, and the angle between adjacent line segments in this polyline is small, less than the preset vector angle. At this time, delete the data points between the two endpoints to obtain a straight line with only two endpoints.

[0074] Deleting collinear data points can reduce the number of contour vectors. Its working principle is to merge consecutive vectors on the same line, which will reduce the file size of the resulting slice. The reduction of points can also prevent the situation of rough physical part surfaces in extreme cases where part defects cause a high concentration of vectors, avoiding causing the machine software to make the laser expose for a longer time in areas with a high concentration of vectors.

[0075] Step 105: Use an open contour stitching algorithm to fill the gaps in the second slice contour set to obtain a third slice contour set; the third slice contour set is used to generate the non-solid support printing path of the part.

[0076] If there are problems with the original digital model, the user does not process some less obvious approximate bad edges, or directly performs slicing without checking for part errors after performing certain operations, there may be some gaps that should not appear. In this case, gap filling is required. Specifically:

[0077] See Figure 5 , traverse all the data points in the second slice contour set to find the target endpoints. The target endpoints are the endpoints of the contour lines in the second slice contour. Check whether there is another point of the open contour within the preset gap length radius of the target endpoints. If so, determine the points within the preset gap length radius of the target endpoints as the target data points, and connect the line segments corresponding to the target endpoints and the target data points, that is, merge two open paths into one. It should be noted that the preset gap length radius is a default value, an empirical value obtained during the data processing, applicable to all graphics, and this value can be set. Different parts and different operations may require different values.

[0078] After obtaining the third slice contour set, it is also necessary to deburr the data in the third slice contour set. Specifically:

[0079] Delete the closed contours in the third slice contour set whose length is less than the preset length value to obtain the deleted slice contour set; as Figure 6 shown, if the data points in the third slice contour set form a smaller contour and the maximum length of the contour is less than the preset length value, then this contour is a burr and this contour is deleted.

[0080] Traverse any two adjacent line segments in the set of sliced contours after deletion, and determine a set of line segments with an included angle less than a preset included angle;

[0081] Determine a set of line segments in the set of line segments that enclose an area less than a preset area, and connect the endpoints in the set of line segments that enclose an area less than the preset area to obtain a target set of sliced contours; in this case, the formed contour has jagged and fine burrs that need to be removed.

[0082] Generate a non-solid support printing path for the part based on the target set of sliced contours.

[0083] The path planning method for the non-solid support of this part sorts and de-duplicates the points in the dataset by using the interpolation method, deletes the collinear data points in the first set of sliced contours that meet the preset collinear condition, and other processing of the contours, which greatly reduces the amount of data in the set of contour points, reduces the storage and transmission overhead of the sliced data, and at the same time removes some unnecessary points, which can reduce the pause of the laser during the printing process, make the printed lines smooth, and reduce the consumption of consumables; use the open contour stitching algorithm to fill the gaps in the second set of sliced contours to obtain the third set of sliced contours; filling and stitching the disconnected line segments can reduce the total laser jump length, reduce the number of breaks, and improve the laser printing efficiency and quality. In addition, removing defects such as burrs and frayed edges further reduces the memory size of the set of contour points, removes some unnecessary printing paths, and further improves the printing efficiency.

[0084] The embodiments of the present invention can divide functional modules according to the above method examples. For example, each functional module can be divided corresponding to each function, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiments of the present invention is illustrative, only a logical function division, and there can be other division methods in actual implementation.

[0085] In the case of dividing each functional module corresponding to each function, Figure 7 shows a schematic structural diagram of a path planning device for non-solid support of a part provided by the present invention. As Figure 7 shown, the device includes:

[0086] A three-dimensional model acquisition module 701, configured to acquire a three-dimensional model of the non-solid support of the part and the slice thickness; the three-dimensional model is composed of unordered triangular patches;

[0087] An intersecting line segment extraction module 702, configured to extract the intersecting line segments of each triangular patch in the three-dimensional model with each slice plane according to the slice thickness to obtain a dataset;

[0088] The duplicate removal and sorting module 703 is used to remove duplicates from the points in the dataset, and sort the points in the dataset after duplicate removal using the interpolation method to obtain the first slice contour set;

[0089] The collinear data point deletion module 704 that meets the preset collinear condition is used to delete the collinear data points that meet the preset collinear condition in the first slice contour set to obtain the second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than the preset vector angle;

[0090] The gap filling module 705 is used to fill the gaps in the second slice contour set using the open contour stitching algorithm to obtain the third slice contour set; the third slice contour set is used to generate the non-solid support printing path of the part.

[0091] Optionally, the device further includes a burr and flash removal module, which may specifically include:

[0092] The closed contour deletion unit is used to delete the closed contours in the third slice contour set with a length less than the preset length value to obtain the deleted slice contour set;

[0093] The line segment group determination unit is used to traverse any two adjacent line segments in the deleted slice contour set to determine the line segment group with an included angle less than the preset included angle;

[0094] The flash determination unit is used to determine the line segment group in the line segment group that encloses an area less than the preset area, and connect the endpoints in the line segment group that encloses an area less than the preset area to obtain the target slice contour set;

[0095] The printing path generation unit is used to generate the non-solid support printing path of the part based on the target slice contour set.

[0096] Optionally, the intersecting line segment extraction module 702 may specifically include:

[0097] The slice plane height determination unit is used to determine the height of each slice plane according to the slice thickness and the height of the non-solid support of the part;

[0098] The target triangular patch determination unit is used to traverse each triangular patch for any layer of slice plane, and determine the triangular patch that meets any one of the height preset conditions as the target triangular patch intersecting with the current slice plane; the height preset conditions include:

[0099] P0.z < z && p1.z >= z && p2.z >= z

[0100] P0.z > z && p1.z < z && p2.z < z

[0101] P1.z < z && p0.z >= z && p2.z >= z

[0102] P1.z > z && p0.z < z && p2.z < z

[0103] P2.z < z && p1.z >= z && p0.z >= z

[0104] P2.z > z && p1.z < z && p0.z < z

[0105] Wherein, P0.z is the height of the first vertex of the triangular patch, p1.z is the height of the second vertex of the triangular patch, p2.z is the height of the third vertex of the triangular patch, and z is the height of the current slicing plane;

[0106] An intersection segment extraction unit, configured to extract the intersection segment of the target triangular patch and the current slicing plane, and obtain a slice contour set corresponding to the current slicing plane;

[0107] A repeated extraction unit, configured to complete the extraction of the intersection segments corresponding to all layer slicing planes, and obtain a data set.

[0108] Optionally, the deduplication and sorting module 703 may specifically include:

[0109] A deduplication unit, configured to traverse the line segments in the data set, remove the line segments with coincident start and end points, and obtain a deduplicated data set;

[0110] A sorting unit, configured to traverse the line segments in the deduplicated data set, and insert the end point of the current line segment after the target start point in the deduplicated data set to obtain a first slice contour set; the target start point is the point coincident with the start point of the current line segment;

[0111] Or, insert the start point of the current line segment before the target end point in the deduplicated data set to obtain a first slice contour set, where the target end point is the point coincident with the end point of the current line segment;

[0112] Or, insert the current line segment after the target line segment to obtain a first slice contour set; the target line segment is the line segment with the shortest distance from the current line segment.

[0113] Optionally, the data point deletion module 704 that meets the preset collinearity condition may specifically include:

[0114] A first collinear point removal unit, configured to traverse the data points in the first slice contour set, determine multiple data points that form a straight line, delete all data points except the endpoints in the formed straight line, and connect the endpoints of the straight line;

[0115] The second collinear point removal unit is configured to determine multiple data points that form a target broken line, delete the points of the target broken line except the endpoints, and connect the endpoints of the target broken line to obtain a second slice contour set; the included angle between adjacent line segments in the target broken line is less than a preset vector angle.

[0116] Optionally, the gap filling module 705 may specifically be configured to:

[0117] Determine the points within the preset gap length radius of the target endpoint as target data points, and connect the line segment corresponding to the target endpoint and the target data points; the target endpoint is the endpoint of the contour line in the second slice contour.

[0118] Optionally, the slice plane height determination unit may specifically be configured to:

[0119] Determine the number of slice layers according to the result of dividing the height of the non-solid support of the part by the slice thickness;

[0120] Multiply the number of layers of each slice plane by the slice thickness to obtain the height of each slice plane.

[0121] The above path planning device for non-solid support of a part is a virtual device, including virtual units and virtual function modules. This device is used on a laser additive manufacturing device. At the same time, a path planning device for non-solid support of a part provided by the present invention corresponds to a path planning method for non-solid support of a part and acts on a laser additive manufacturing device.

[0122] The above mainly introduces the solution provided by the embodiments of the present invention from the perspective of the interaction between various modules. It can be understood that, in order to implement the above functions, it includes the corresponding hardware structure and / or software module for executing each function. Those skilled in the art should easily realize that, combining the units and algorithm steps of each example described in the embodiments disclosed herein, the present invention can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is executed in the way of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0123] In the case of adopting corresponding integrated units, Figure 8 The structural schematic diagram of a path planning device for non-solid support of a part provided by the present invention is shown. As Figure 8 shown, the device includes:

[0124] A communication unit / communication interface, configured to obtain a three-dimensional model of the non-solid support of the part and the slice thickness; the three-dimensional model is composed of unordered triangular meshes;

[0125] A processing unit / processor, according to the slice thickness, extracts the intersection line segments of each triangular facet in the three-dimensional model with each slice plane to obtain a data set;

[0126] Deduplicate the points in the data set, and sort the points in the deduplicated data set by interpolation to obtain a first slice contour set;

[0127] Delete the collinear data points in the first slice contour set that meet the preset collinear condition to obtain a second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than a preset vector angle;

[0128] Use an open contour stitching algorithm to fill the gaps in the second slice contour set to obtain a third slice contour set; the third slice contour set is used to generate a non-solid support printing path for the part.

[0129] The above-mentioned path planning device for non-solid support of a part is used on a laser additive manufacturing device. At the same time, a path planning device for non-solid support of a part provided by the present invention corresponds to a path planning method for non-solid support of a part and acts on a laser additive manufacturing device.

[0130] In some possible implementation manners, the above-mentioned device may further include a storage module for storing program codes and data of the base station.

[0131] Among them, the processing unit may be a processor or a controller. For example, it may be a central processing unit (CPU), a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in connection with the disclosure of the present invention. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The communication module may be a transceiver, a transceiver circuit or a communication interface, etc. The storage module may be a memory.

[0132] Such as Figure 8 As shown, the above-mentioned processor may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of the program of the present invention. The above-mentioned communication interface(s) may be one or more. The communication interface may use any device such as a transceiver for communicating with other devices or communication networks.

[0133] As Figure 8 shown, the above-mentioned device may further include a communication line. The communication line may include a path for transmitting information between the above-mentioned components.

[0134] Optionally, as Figure 8 shown, the device may further include a memory. The memory is used to store computer-executable instructions for executing the solution of the present invention and is controlled by the processor for execution. The processor is used to execute the computer-executable instructions stored in the memory, thereby implementing the method provided by the embodiments of the present invention.

[0135] As Figure 8 shown, the memory may be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory may exist independently and be connected to the processor through a communication line. The memory may also be integrated with the processor.

[0136] Optionally, the computer-executable instructions in the embodiments of the present invention may also be referred to as application code, and the embodiments of the present invention do not make specific limitations thereto.

[0137] In a specific implementation, as an embodiment, as Figure 8 shown, the processor may include one or more CPUs, such as Figure 8 the CPU0 and CPU1 in

[0138] In a specific implementation, as an example, as Figure 8 shown, the terminal device may include multiple processors, such as Figure 8 the processors in . Each of these processors may be a single-core processor or a multi-core processor.

[0139] On the one hand, a computer-readable storage medium is provided, in which instructions are stored. When the instructions are run, the above-mentioned path planning method for non-physical support of parts is implemented.

[0140] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present invention are executed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a terminal, a user device, or other programmable devices. The computer program or instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer program or instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center in a wired or wireless manner. The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; it may also be an optical medium, such as a digital video disc (DVD); or it may be a semiconductor medium, such as a solid state drive (SSD).

[0141] Although the present invention has been described in conjunction with various embodiments herein, however, in the process of implementing the claimed invention, those skilled in the art can understand and implement other variations of the disclosed embodiments by viewing the drawings, the disclosure content, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality of cases. A single processor or other unit may implement several functions recited in the claims. Certain measures are recited in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0142] Although the present invention has been described in connection with specific features and their embodiments, it will be apparent that various modifications and combinations can be made without departing from the spirit and scope of the invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the invention defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.< / polygon> < / point>

Claims

1. A path planning method for non-solid support of parts, characterized in that Including: Obtain the three-dimensional model of the non-solid support of the part and the slice thickness; The three-dimensional model is composed of unordered triangular facets; According to the slice thickness, extract the intersection line segments of each triangular facet in the three-dimensional model with each slice plane to obtain a data set; Deduplicate the points in the data set, and use the interpolation method to sort the points in the deduplicated data set to obtain the first slice contour set; Delete the collinear data points in the first slice contour set that meet the preset collinear condition to obtain the second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than the preset vector angle; Use the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set; the third slice contour set is used to generate the printing path of the non-solid support of the part.

2. The path planning method for non-solid support of parts according to claim 1, wherein After using the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set, it further includes: Delete the closed contours in the third slice contour set with a length less than the preset length value to obtain the deleted slice contour set; Traverse any two adjacent line segments in the deleted slice contour set to determine the line segment groups with an included angle less than the preset included angle; Determine the line segment groups in the line segment groups that enclose an area less than the preset area, and connect the endpoints in the line segment groups that enclose an area less than the preset area to obtain the target slice contour set; Generate the printing path of the non-solid support of the part based on the target slice contour set.

3. The path planning method for non-solid support of parts according to claim 1, wherein The step of extracting the intersection line segments of each triangular facet in the three-dimensional model with each slice plane according to the slice thickness to obtain a data set includes: Determine the height of each slice plane according to the slice thickness and the height of the non-solid support of the part; For any layer of slice plane, traverse each triangular facet, and determine the target triangular facet that intersects with the current slice plane as the triangular facet that meets any one of the height preset conditions; the height preset conditions include: P0.z < z && p1.z >= z && p2.z >= z P0.z > z && p1.z < z && p2.z < z P1.z < z && p0.z >= z && p2.z >= z P1.z > z && p0.z < z && p2.z < z P2.z < z && p1.z >= z && p0.z >= z P2.z > z && p1.z < z && p0.z < z Wherein, P0.z is the height of the first vertex of the triangular facet, p1.z is the height of the second vertex of the triangular facet, p2.z is the height of the third vertex of the triangular facet, and z is the height of the current slice plane; Extract the intersection line segment of the target triangular facet and the current slice plane to obtain the slice contour set corresponding to the current slice plane; Complete the extraction of the intersection line segments corresponding to all layers of slice planes to obtain a data set.

4. The path planning method for non-solid support of parts according to claim 1, characterized in that, The step of deduplicating the points in the data set and using the interpolation method to sort the points in the deduplicated data set to obtain the first slice contour set includes: Traverse the line segments in the data set, and remove the line segments with coincident start and end points to obtain the deduplicated data set; Traverse the line segments in the deduplicated dataset, and insert the end point of the current line segment after the target start point in the deduplicated dataset to obtain the first slice contour set; the target start point is the point that coincides with the start point of the current line segment; Or, insert the start point of the current line segment before the target end point in the deduplicated dataset to obtain the first slice contour set, where the target end point is the point that coincides with the end point of the current line segment; Or, insert the current line segment after the target line segment to obtain the first slice contour set; the target line segment is the line segment with the shortest distance from the current line segment.

5. The path planning method for non-solid support of parts according to claim 1, wherein The deleting the collinear data points that meet the preset collinear condition in the first slice contour set to obtain the second slice contour set includes: Traverse the data points in the first slice contour set, determine the multiple data points that form a straight line, delete all the data points except the endpoints in the formed straight line, and connect the endpoints of the straight line; Determine the multiple data points that form the target broken line, delete the points except the endpoints of the target broken line, and connect the endpoints of the target broken line to obtain the second slice contour set; the included angle between adjacent line segments in the target broken line is less than the preset vector angle.

6. The path planning method for non-solid support of parts according to claim 1, characterized in that The using the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set includes: Determine the points within the preset gap length radius of the target endpoint as the target data points, and connect the line segments corresponding to the target endpoint and the target data points; the target endpoint is the endpoint of the contour line in the second slice contour.

7. The path planning method for non-solid support of parts according to claim 3, characterized in that, The determining the height of each slice plane according to the slice thickness and the height of the non-solid support of the part includes: Determine the number of slice layers according to the result of dividing the height of the non-solid support of the part by the slice thickness; Multiply the number of layers of each slice plane by the slice thickness to obtain the height of each slice plane.

8. A path planning device for non-solid support of parts, characterized in that, Includes: A 3D model acquisition module, configured to acquire the 3D model of the non-solid support of the part and the slice thickness; The 3D model consists of unordered triangular meshes; An intersecting line segment extraction module, configured to extract the intersecting line segments of each triangular mesh in the 3D model with each slice plane according to the slice thickness to obtain a dataset; A deduplication and sorting module, configured to perform deduplication processing on the points in the dataset, and sort the points in the deduplicated dataset by interpolation to obtain the first slice contour set; A collinear data point deletion module that meets the preset collinear condition, configured to delete the collinear data points that meet the preset collinear condition in the first slice contour set to obtain the second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than the preset vector angle; A gap filling module, configured to use the open contour stitching algorithm to fill the gaps in the second slice contour set to obtain the third slice contour set; the third slice contour set is used to generate the printing path of the non-solid support of the part.

9. A path planning device for non-solid support of parts, characterized in that, Includes: A communication unit / communication interface, configured to acquire the 3D model of the non-solid support of the part and the slice thickness; The 3D model consists of unordered triangular meshes; A processing unit / processor extracts the intersection line segments of each triangular patch in the three-dimensional model with each slice plane according to the slice thickness to obtain a data set; Deduplicate the points in the data set, and sort the points in the deduplicated data set by interpolation to obtain a first slice contour set; Delete the collinear data points in the first slice contour set that meet the preset collinear condition to obtain a second slice contour set; the preset collinear condition is that the data points are on a straight line or the included angle between adjacent line segments in the line segments formed by the data points is less than a preset vector angle; Use an open contour stitching algorithm to fill the gaps in the second slice contour set to obtain a third slice contour set; the third slice contour set is used to generate a non-solid support printing path for the part.

10. A computer-readable storage medium, characterized in that, Instructions are stored in the computer-readable storage medium, and when the instructions are run, the path planning method for non-solid support of the part according to any one of claims 1 to 7 is implemented.

Images