An additive process contour processing method, device, equipment and storage medium

Abstract

The application discloses an additive process contour processing method, device, equipment and storage medium, an algorithm is used for modifying and contour processing an original additive process file, the contour is offset to the outside of the entity, and the extension contour is inclined to overcome the collapse problem. The method can quickly generate the required machining code, can avoid manual operation, improves the production efficiency, avoids the auxiliary mechanism such as the additional turntable, and reduces the equipment modification cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of additive and subtractive manufacturing, in particular to an additive process contour processing method, device, equipment and storage medium. BACKGROUND

[0002] 3D printing (3DP) is a kind of rapid prototyping technology, also known as additive manufacturing, which is a technology that uses digital model files as the basis, and uses powder-like metal or plastic and other materials that can be bonded, to construct objects through layer-by-layer printing.

[0003] 3D printing is usually realized by using a digital technology material printer. It is often used in mold manufacturing, industrial design and other fields to manufacture models, and gradually used for the direct manufacturing of some products. There are parts printed by using this technology. The technology is applied in the fields of jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automobile, aerospace, dental and medical industry, education, geographic information system, civil engineering, gun and other fields.

[0004] In powder-fed additive manufacturing, if the printing head is fixed in a direction for printing, it is easy to collapse for epitaxial structure. At the same time, sometimes it is desired that the additive allowance is large enough to facilitate subsequent processing.

[0005] In the prior art, for epitaxial collapse, the contour speed is greatly reduced during printing, and the contour protrusion is manually polished after each layer is printed. A turntable can also be installed, so that the turntable and the printing head move synchronously during additive printing, so that the printing head basically remains in the vertical direction. For the desired large additive allowance, the model is modified to extend the model outward by a certain size, and then an additive process file is generated for printing.

[0006] However, the processing methods in the prior art have many disadvantages, for example, for epitaxial collapse, the contour is extremely irregular by greatly reducing the contour speed, and the thickness of the contour at this part is large, which needs to be polished and cleaned, and the production efficiency is extremely low; the method of increasing the turntable needs to be modified accordingly because the turntable needs to be linked with the printing head, and the algorithm needs to be greatly modified to control the synchronous movement of the printing head and the turntable. In addition, it is difficult to operate for slightly complex structures by modifying the model to extend outward. SUMMARY

[0007] In view of the above problems, the present application provides an additive process contour processing method, device, equipment and storage medium for overcoming the above problems or at least partially solving the above problems.

[0008] The present application provides the following solutions:

[0009] A method for additive process contour processing, comprising:

[0010] extracting filling and contour information from an additive process file;

[0011] acquiring topological relations among all contours contained in each layer;

[0012] identifying a correspondence relation between contours of different layers to perform contour matching search, the contour matching search comprising finding two or more contours of different layers to establish a connection;

[0013] analyzing each contour feature to perform two contour segment / point matching searches;

[0014] normalizing each contour direction, the normalization comprising an anticlockwise direction for an outer contour and a clockwise direction for an inner contour; performing segment / point matching search between a contour of a layer and a corresponding contour of a position of a next layer to find a tangent vector of each point of the contour to the contour of the next layer, the tangent vector of the contour being used to determine whether the point is an extension structure;

[0015] analyzing the contour and a contour feature of a next layer to find each contour inflection point to perform matching analysis; if matching is failed, finding an intersection point from a vertical bisector plane of a contour vertex; if there is no intersection point, obtaining a nearest point to take a direction of a line connecting the intersection point or the nearest point with the vertex as a direction of a tangent vector; if matching is successful, dividing the contour and a reference contour into multiple segments, taking an inflection point as a direction of a tangent vector at the inflection point, and finding an intersection point or a nearest point of a vertical bisector plane of a contour vertex of each corresponding segment with the reference contour as a direction of a tangent vector; the tangent vector is a direction of an axis of a printing head, and the contour point is a position of the printing head;

[0016] determining that an additive allowance needs to be increased, and performing contour loop adding processing; the loop adding processing comprises offsetting the contour outward from a solid to form multiple loop contours on the basis of the original contour;

[0017] determining that an outermost loop contour belongs to an extension structure, and then tilting the contour according to an actual tangent vector;

[0018] outputting original filling information and modified contour information as additive instruction codes according to characteristics of an NC device.

[0019] Preferably, the contour information contains a circular arc, and the circular arc is polygonized.

[0020] Preferably, acquiring topological relations among all contours contained in each layer comprises:

[0021] The first contour is determined as a level 0 contour, and the contour table is added, and the remaining contours are sequentially checked with each contour in the contour table; if the new contour contains a level 0 contour in the contour table, the new contour is added to the contour table as a level 0 contour; the compared level 0 contour is taken as its sub-contour, and is compared with the remaining contours in the contour table; if the new contour is contained by the compared contour, the comparison with the sub-contours of the compared contour is continued until there is no containing relationship, and the last sub-contour containing the new contour is taken, and the next new contour is checked.

[0022] Preferably, the contour matching search principle includes a contour nesting relationship same principle and a contour geometric center nearest principle.

[0023] Preferably, the contour nesting relationship same principle includes that a contour is represented by a level in a relationship network; contours of different levels are matched at the same level; and the contour geometric center nearest principle includes that two contours are matched if the contour geometric centers are nearest; and if there is a certain torsion angle between two levels, the level is first rotated around a specified center according to a specified rotation angle, and then the contour matching is performed according to the contour geometric center nearest principle.

[0024] Preferably, the analysis of each contour feature for two contour segment / point matching searches includes:

[0025] The analysis of each contour feature includes: if the trend is not the expected trend, the order is reversed to obtain a turning point;

[0026] It is judged whether the turning point is a concave point and whether there is a concave point in the region after the turning point;

[0027] If the number of contour turning points is 0, matching fails, and the matching failure is returned;

[0028] If the number of turning points is not equal, matching is performed according to the shortest distance, and the matching situation is returned;

[0029] If all the turning point attributes are the same, matching is performed according to the shortest distance, and the matching situation is returned;

[0030] According to the attribute feature matching, if the matching can be performed, the matching situation is returned;

[0031] According to the shortest distance, matching is performed, and the matching situation is returned.

[0032] An additive process contour processing device, the device comprising:

[0033] A contour information acquisition unit is configured to extract filling and contour information from an additive process file;

[0034] A topological relationship acquisition unit is configured to acquire topological relationships among all contours contained by each layer;

[0035] a contour matching search unit for identifying the correspondence of the contours between different layers and performing a contour matching search, the contour matching search including finding two or more contours between different layers to establish a connection;

[0036] two contour segment / point matching search units for analyzing each contour feature to perform a two contour segment / point matching search;

[0037] an epitaxial structure determination unit for normalizing each contour direction, the normalizing including an outer contour counterclockwise direction and an inner contour clockwise direction; performing a segment / point matching search between a contour of a layer and a corresponding contour at a position of a next layer of the contour, finding a tangent vector of each point of the contour and a tangent vector of the next layer contour, and determining whether the point of the contour is an epitaxial structure based on the tangent vector of the contour;

[0038] a printhead axial direction and position determination unit for analyzing the contour and a next layer contour feature to find each contour inflection point, performing a matching analysis, if a match is not found, finding an intersection point from a vertical bisector plane of a contour vertex, if there is no intersection point, obtaining a nearest point, and using an intersection point or a nearest point and a vertex connecting line direction as a tangent line vector direction, if a match is found, dividing the contour and a reference contour into multiple segments, using an inflection point as a tangent line vector direction at the inflection point, and using an intersection point or a nearest point of a contour vertex vertical bisector plane and the reference contour as a tangent line vector direction for the remaining points in each corresponding segment, the tangent line vector being a printhead axial direction, and the contour point being a printhead position;

[0039] a loop adding unit for determining that an additive allowance needs to be increased, and adding a loop to the contour, the adding a loop including offsetting the contour outward from a solid based on the original contour to form a multi-loop contour;

[0040] a vector tilting unit for determining that the outermost loop contour is an epitaxial structure, and tilting the contour according to an actual tangent line vector;

[0041] a code output unit for outputting original filling information and modified contour information as additive instruction codes according to NC device features.

[0042] An additive process contour processing device, the device including a processor and a memory:

[0043] the memory is configured to store program codes and transmit the program codes to the processor;

[0044] the processor is configured to execute the additive process contour processing method according to instructions in the program codes.

[0045] A computer readable storage medium for storing program codes, the program codes being configured to execute the additive process contour processing method.

[0046] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0047] This application provides an additive manufacturing process contour processing method, apparatus, equipment, and storage medium. The algorithm modifies the contour of the original additive manufacturing process file, shifting the contour outwards and tilting the extended contour to overcome the collapse problem. This method can quickly generate the required processing code; it also avoids manual operation, improving production efficiency; furthermore, it eliminates the need for auxiliary mechanisms such as turntables, reducing equipment modification costs.

[0048] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0050] Figure 1 This is a flowchart of an additive manufacturing process contour processing method provided in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of an additive manufacturing contour processing device provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of an additive manufacturing contour processing device provided in an embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0054] See Figure 1 This invention provides an additive manufacturing process contour processing method, such as... Figure 1 As shown, the method may include:

[0055] S101: Extract filling and contour information from the additive manufacturing process file; specifically, the contour information includes arcs, and the arcs are polygonized.

[0056] S102: Obtain the topological relationship between all contours contained in each layer; specifically, determine the first contour as the level 0 contour, add the contour to the contour table, and sequentially check the relationship between the remaining contours and each contour in the contour table; if the new contour contains the level 0 contour in the contour table, the new contour is added to the contour table as the level 0 contour; the level 0 contour is compared as its child contour, and then compared with the remaining contours in the contour table; if the new contour is contained by the compared contour, the child contour of the compared contour is continuously compared until there is no containing relationship, the last child contour containing the new contour is checked, and the next new contour is checked.

[0057] S103: Identify the corresponding relationship between the contours of different layers for contour matching search, the contour matching search includes finding two or more contours between different layers to establish a connection; specifically, the principle of the contour matching search includes the same contour nesting relationship principle and the contour centroid nearest principle. Further, the same contour nesting relationship principle includes that a contour is represented by a level in the relationship network; the contour matching of different layers is at the same level; the contour centroid nearest principle includes that the contour geometric center is nearest, and then the two contours are matched; if there is a certain torsion angle between two layers, the layer is first rotated around the specified center according to the specified rotation angle, and then matched by the contour centroid nearest principle.

[0058] S104: Analyze each contour feature for two contour segment / point matching searches; specifically, analyze each contour feature: if the trend is not the expected trend, reverse the order to obtain the inflection point;

[0059] Determine whether the inflection point is a concave point and whether there is a concave point in the region after the inflection point;

[0060] If the number of contour inflection points is 0, matching fails, and the matching failure is returned;

[0061] If the number of inflection points is not equal, matching is performed according to the shortest distance, and the matching situation is returned;

[0062] If all inflection point attributes are the same, matching is performed according to the shortest distance, and the matching situation is returned;

[0063] According to the attribute feature matching, if it can be matched, the matching situation is returned;

[0064] Matching is performed according to the shortest distance, and the matching situation is returned.

[0065] S105: Normalize each contour direction, the normalization includes the counterclockwise direction of the outer contour and the clockwise direction of the inner contour; perform segment / point matching search on the contour of a layer and the corresponding contour at the position of the next layer, find the tangent vector of each point of the contour and the contour of the next layer, and the tangent vector of the contour is used to determine whether the point of the contour is an extension structure;

[0066] S106: Analyzing the profile and the next layer profile feature to find each profile inflection point, and performing matching analysis; if matching is not possible, then the intersection point is found by making a vertical bisector from the profile vertex; if there is no intersection point, then the nearest point is obtained, and the intersection point or the nearest point and the vertex connecting line direction are taken as the knife line vector direction; if matching is possible, then the profile and the reference profile are divided into multiple segments for correspondence, and at the inflection point, the inflection point is taken as the knife line vector direction, and the rest of the points are taken as the knife line vector direction according to the intersection point or the nearest point of the vertical bisector of the profile vertex and the reference profile in each corresponding segment; the knife line vector is the axial direction of the print head, and the profile point is the position of the print head;

[0067] S107: Determining that the additive allowance needs to be increased, and performing a profile loop processing on the profile; the loop processing includes offsetting the profile outward from the entity on the basis of the original profile to form a multi-loop profile.

[0068] S108: Determining that the outermost loop profile belongs to an epitaxial structure, and then tilting the profile according to the actual knife line vector.

[0069] S109: Outputting the original filling information and the modified profile information as additive instruction codes according to the characteristics of the NC equipment.

[0070] The additive process profile processing method provided by the embodiments of the present application establishes an algorithm, modifies the profile of the original additive process file, offsets the profile outward from the entity, and tilts the epitaxial profile to overcome the collapse problem. The method can quickly generate the required machining codes; at the same time, it can avoid manual operation and improve production efficiency; in addition, it avoids the installation of auxiliary mechanisms such as a rotary table, and reduces the equipment modification cost.

[0071] The additive process profile processing method provided by the embodiments of the present application will be described in detail below.

[0072] Filling and profile acquisition:

[0073] The filling and profile information is extracted from the additive process file. The extracted profile may contain an arc, and needs to be polygonized for subsequent processing.

[0074] Layer profile topology analysis:

[0075] The topology relationship analysis between all profiles in a layer is obtained. Each profile has a hierarchical relationship in a layer, which first contains one or more outer profiles, i.e., level 0 outer profile, each level 0 outer profile may contain 0 or more level 1 inner profiles, and the level 1 inner profile may contain level 2 outer profiles, and so on.

[0076] Analysis method: Set the first profile as level 0 profile, add the profile table, and check the relationship between the remaining profiles and each profile in the profile table in turn. If the new profile contains the level 0 profile in the profile table, the new profile is added to the profile table as the level 0 profile, and the compared level 0 profile is used as its child profile, and then compared with the remaining profiles in the profile table; if the new profile is contained by the compared profile, the child profile of the compared profile is compared, until there is no containing relationship, then the last child profile containing the new profile is checked for the next new profile.

[0077] Different layer profile matching search:

[0078] Identify the corresponding relationship between the profiles of different layers, that is, which profile of another layer corresponds to one profile of a layer. The tool direction is obtained by first establishing the corresponding relationship between the profiles of different layers, that is, finding the profile corresponding to the profile of another layer, which is called profile matching search.

[0079] Profile matching search is to find two or more profiles to establish a relationship, so that the structure of the composite model is characterized. If there is a spatial transformation relationship of rotation and translation between one layer and another layer, the transformation is first corrected. A simple principle of such matching search is the same principle of profile nesting relationship and the principle of nearest profile centroid distance.

[0080] The profile nesting relationship is the nesting relationship of the profiles in the same layer, and the outermost profile level is 0. Profiles of the same level can have multiple brothers. The same principle of profile nesting relationship is that the profiles of different layers must be matched at the same level first.

[0081] The nearest profile centroid distance principle is to use the geometric center of the profile. If the geometric centers are nearest, it is considered that the two profiles match. This principle is not absolute, but a relatively effective reference standard.

[0082] If there is a certain torsion angle between two layers, first rotate one layer around a specified center by a specified rotation angle, and then use the nearest profile centroid distance principle to match.

[0083] Two profile segment / point matching search:

[0084] 1. First, analyze each profile feature: if the direction is not the expected direction, reverse the order, get the inflection point, whether the inflection point is a concave point, and whether there is a concave point in the area after the inflection point;

[0085] 2. If the number of profile inflection points is 0, matching fails and returns;

[0086] 3. If the number of inflection points is not equal, match according to the shortest distance, and return the matching condition;

[0087] 4、If all the inflection points are the same, match according to the shortest distance, and return the matching condition;

[0088] 5、According to the attribute characteristics matching, if it can be matched, return the matching condition;

[0089] 6、According to the shortest distance for matching, return the matching condition.

[0090] Epitaxial structure judgment:

[0091] Normalize the contour direction, that is, the outer contour is counterclockwise, and the inner contour is clockwise.

[0092] Match the contour of a layer with the corresponding contour of the next layer position, find out the tangent vector of each point of the contour and the contour of the lower layer, and together with the tangent vector of the contour, it can be determined whether the contour is an epitaxial structure at this point.

[0093] Print head position posture calculation when epitaxial contour is inclined:

[0094] Analyze the contour and the next layer contour characteristics, find the inflection points of each contour, and perform matching analysis. If it cannot be matched, a vertical bisector plane is made from the contour vertex, the intersection point is found, if there is no intersection point, the nearest point is obtained, and the intersection point or the nearest point and the vertex line direction are taken as the direction of the tangent vector. If it can be matched, the contour and the reference contour are divided into multiple segments, and at the inflection point, the inflection point is taken as the direction of the tangent vector, and the intersection point or the nearest point of the reference contour is taken as the direction of the tangent vector.

[0095] The tangent vector is the axial direction of the print head, and the contour point is the position of the print head.

[0096] Contour loop and inclination processing:

[0097] If it is necessary to increase the additive allowance, the contour is looped and processed, that is, on the basis of the original contour, the contour is offset to the outside of the entity to form a multi-loop contour.

[0098] For the outermost loop contour, and belongs to the epitaxial structure, the contour is inclined according to the actual tangent vector, so as to ensure epitaxial growth.

[0099] NC code modification output:

[0100] According to the NC device characteristics, the original filling information and the modified contour information are output as additive instruction codes.

[0101] Referring to Figure 2 , the embodiments of the present application can also provide an additive process contour processing device, as shown in Figure 2 , which can include:

[0102] The contour information acquisition unit 201 is configured to extract filling and contour information from the additive manufacturing process file;

[0103] The topological relationship acquisition unit 202 is configured to acquire the topological relationship between all contours contained in each layer;

[0104] The contour matching search unit 203 is configured to identify the corresponding relationship between contours in different layers for contour matching search, and the contour matching search includes finding two or more contours in different layers to establish a connection;

[0105] The two-contour segment / point matching search unit 204 is configured to analyze each contour feature for two-contour segment / point matching search;

[0106] The epitaxial structure discrimination unit 205 is configured to normalize each contour direction, and the normalization includes the anticlockwise direction of the outer contour and the clockwise direction of the inner contour; the contour of one layer is subjected to segment / point matching search with the corresponding contour at the position of the next layer to find the tangent vector of each point of the contour to the contour of the next layer, and the tangent vector of the contour is used to discriminate whether the point is an epitaxial structure;

[0107] The print head axial direction and position determination unit 206 is configured to analyze the contour and the contour feature of the next layer to find the inflection point of each contour for matching analysis; if the matching cannot be performed, the intersection point is found by performing vertical bisector on the contour vertex; if there is no intersection point, the nearest point is acquired to take the intersection point or the nearest point and the vertex connecting line direction as the tangent line vector direction; if the matching can be performed, the contour and the reference contour are divided into multiple segments for correspondence, the inflection point is taken as the tangent line vector direction at the inflection point, and the intersection point or the nearest point of the vertical bisector of the contour vertex and the reference contour is taken as the tangent line vector direction of the remaining points in each corresponding segment; the tangent line vector is the print head axial direction, and the contour point is the print head position;

[0108] The loop adding unit 207 is configured to determine that the additive allowance needs to be increased, and perform loop adding processing on the contour; the loop adding processing includes offsetting the contour outward from the solid on the basis of the original contour to form a multi-loop contour;

[0109] The vector tilting unit 208 is configured to determine that the outermost loop contour belongs to an epitaxial structure, and then tilt the contour according to the actual tangent line vector;

[0110] The code output unit 209 is configured to output the original filling information and the modified contour information as additive instruction codes according to the characteristics of the NC device.

[0111] The embodiment of the application can also provide an additive manufacturing process contour processing device, and the device includes a processor and a memory:

[0112] The memory is configured to store program codes and transmit the program codes to the processor;

[0113] The processor is configured to execute the steps of the additive process contour processing method according to the instructions in the program code.

[0114] As shown in Figure 3 The additive process contour processing device provided by the embodiment of the present application can include a processor 10, a memory 11, a communication interface 12 and a communication bus 13. The processor 10, the memory 11 and the communication interface 12 can communicate with each other through the communication bus 13.

[0115] In the embodiment of the present application, the processor 10 can be a central processing unit (CPU), an application specific integrated circuit, a digital signal processor, a field programmable gate array or other programmable logic device, etc.

[0116] The processor 10 can call the program stored in the memory 11. Specifically, the processor 10 can execute the operations in the embodiment of the additive process contour processing method.

[0117] The memory 11 is used to store one or more programs. The program can include program code, and the program code includes computer operation instructions. In the embodiment of the present application, the memory 11 at least stores a program for implementing the following functions:

[0118] Extracting filling and contour information from the additive process file;

[0119] Obtaining the topological relationship between all contours contained in each layer;

[0120] Identifying the corresponding relationship between the contours of different layers to perform contour matching search, and the contour matching search includes finding two or more contours between different layers to establish a connection;

[0121] Analyzing each contour feature to perform two contour section / point matching searches;

[0122] Normalizing each contour direction, which includes the counterclockwise direction of the outer contour and the clockwise direction of the inner contour; performing section / point matching search on the contour of a layer and the corresponding contour of the next layer position to find the tangent vector of each point of the contour and the contour of the next layer, and the tangent vector of the contour is used to determine whether the point of the contour is an extension structure;

[0123] The profile and the next profile feature are analyzed to find the profile inflection points, and matching analysis is performed; if matching is not possible, the intersection point is found from the profile vertex perpendicular bisector; if there is no intersection point, the nearest point is obtained, and the intersection point or the nearest point and the vertex connecting line direction are taken as the direction of the knife line vector; if matching is possible, the profile and the reference profile are divided into multiple corresponding segments, and at the inflection point, the inflection point is taken as the direction of the knife line vector, and the rest of the points are taken as the intersection point or the nearest point of the profile vertex perpendicular bisector and the reference profile as the direction of the knife line vector in each corresponding segment; the knife line vector is the axial direction of the print head, and the profile point is the position of the print head;

[0124] It is determined that the additive allowance needs to be increased, and the profile is handled by adding a circle; the adding-a-circle handling includes offsetting the profile outward from the entity based on the original profile to form a multi-circle profile;

[0125] It is determined that the outermost circle profile belongs to an epitaxial structure, and the profile is inclined according to the actual knife line vector;

[0126] According to the characteristics of the NC device, the original filling information and the modified profile information are output as additive instruction codes.

[0127] In a possible implementation, the memory 11 can include a program storage area and a data storage area, where the program storage area can store an operating system, and application programs required by at least one function (such as a file creation function, a data read-write function), and the like; and the data storage area can store data created in the use process, such as initialization data and the like.

[0128] In addition, the memory 11 can include a high-speed random access memory, and can also include a non-volatile memory, for example, at least one magnetic disk storage device or other volatile solid-state storage device.

[0129] The communication interface 12 can be an interface of a communication module, used to connect with other devices or systems.

[0130] Of course, it needs to be explained that, Figure 3 The structures shown do not constitute a limitation on the additive process profile processing device in the embodiments of the present application, and in actual applications, the additive process profile processing device can include more or fewer components than Figure 3 those shown, or some components can be combined.

[0131] The embodiments of the present application can also provide a computer readable storage medium for storing program codes, the program codes being used to execute the steps of the additive process profile processing method described above.

[0132] It is to be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "includes a", "including", does not, without more constraints, preclude the existence of additional identical elements other than the listed elements.

[0133] Those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary universal hardware platform from the description of the above embodiments. Based on such an understanding, the technical solutions of the present application can be embodied in a software product form, which can be stored in a storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in the various embodiments or some parts of the embodiments of the present application.

[0134] The various embodiments in the present specification are described in a progressive manner, and the same or similar parts among the various embodiments can be mutually referred to, and each embodiment mainly describes the differences from other embodiments. In particular, for the system or system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the description of the method embodiments. The above-described system and system embodiments are merely illustrative, and the units described as separate components can be or can not be physically separated, and the components displayed as units can be or can not be physical units, i.e., they can be located in one place, or can be distributed on multiple network units. According to actual needs, some or all of the modules can be selected to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement without creative labor.

[0135] The above only describes the preferred embodiments of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application is included in the protection scope of the present application.

Claims

1. A method for contour processing in additive manufacturing, characterized in that, include: Extract fill and contour information from additive manufacturing process files; Obtain the topological relationships between all contours contained in each layer; The method for obtaining topological relationships includes: The first contour is identified as a level 0 contour and added to the contour table. The relationship between the remaining contours and each contour in the contour table is checked in turn. If a new contour contains a level 0 contour in the contour table, the new contour is added to the contour table as a level 0 contour. The level 0 contour being compared is taken as its child contour, and then compared with the remaining contours in the contour table. If the new contour is contained by the compared contour, the comparison with the child contours of the compared contour continues until there is no containment relationship. This is taken as the last child contour containing the new contour, and the next new contour is checked. Identify the correspondence between contours in different layers and perform contour matching search, wherein the contour matching search includes finding two or more contours in different layers and establishing a relationship; Analyze each contour feature and perform two contour segment / point matching searches; Each contour direction is normalized, including the outer contour in a counterclockwise direction and the inner contour in a clockwise direction; the contour of one layer is matched with the corresponding contour of the next layer in a segment / point matching search to find the tangent vector between each point of the contour and the lower contour, and the contour tangent vector is used to determine whether the contour is an extension structure at this point. The contour and the next layer contour features are analyzed to find the inflection points of each contour and perform matching analysis. If no match can be found, the intersection point is obtained by constructing a perpendicular bisector from the contour vertex. If there is no intersection point, the nearest point is obtained and the direction of the line connecting the intersection point or the nearest point and the vertex is used as the direction of the tangent vector. If a match can be found, the contour and the reference contour are divided into multiple corresponding segments. At the inflection point, the inflection point is used as the basis for the direction of the tangent vector. For the remaining points, the intersection point of the perpendicular bisector of the contour vertex and the reference contour or the nearest point is found in each corresponding segment as the basis for the direction of the tangent vector. The tangent vector is the axial direction of the print head, and the contour point is the position of the print head. If it is determined that the additive manufacturing allowance needs to be increased, the contour is processed by adding circles; the circle processing includes offsetting the contour outward from the solid based on the original contour to form a multi-circle contour; If the outermost contour is determined to be an extensional structure, then the contour is tilted according to the actual cutting edge tangent vector; Based on the characteristics of the NC device, the original filling information and the modified contour information are output as additive manufacturing instruction codes.

2. The additive manufacturing contour processing method according to claim 1, characterized in that, The contour information includes arcs, which are then polygonized.

3. The additive manufacturing process contour processing method according to claim 1, characterized in that, The principles of contour matching search include the principle of identical contour nesting relationship and the principle of closest contour centroid distance.

4. The additive manufacturing process contour processing method according to claim 3, characterized in that, The principle of identical contour nesting relationships includes that a contour is represented by a level in the relationship network; contours from different layers are matched at the same level; the principle of closest contour centroid distance includes that if the geometric centers of the contours are closest, then the two contours are matched; if there is a certain twist angle between two layers, one layer is first rotated around the specified center by the specified angle, and then matched according to the principle of closest contour centroid distance.

5. The additive manufacturing contour processing method according to claim 1, characterized in that, The analysis of each contour feature involves two contour segment / point matching searches, including: Analyze each contour feature: if the direction is not as expected, reverse its order to obtain the inflection point; Determine whether the inflection point is a concave point, and whether there are concave points in the region after the inflection point; If the number of inflection points in a contour is 0, a match cannot be made, and a match failure is returned. If the number of inflection points is not equal, then match according to the shortest distance and return the matching results; If all inflection point attributes are the same, then match based on the shortest distance and return the matching results; Match based on attribute features; if a match is found, return the matching result. Matches are performed based on the shortest distance, and the matching results are returned.

6. An additive manufacturing contour processing apparatus, characterized in that, The apparatus for performing the additive manufacturing contour processing method according to any one of claims 1-5, the apparatus comprising: The contour information acquisition unit is used to extract filling and contour information from the additive manufacturing process file; The topology relationship acquisition unit is used to acquire the topology relationships between all contours contained in each layer; A contour matching search unit is used to identify the correspondence between contours in different layers and perform contour matching search. The contour matching search includes finding two or more contours in different layers and establishing a connection. Two contour segment / point matching search units are used to analyze each contour feature and perform two contour segment / point matching searches. An extensional structure discrimination unit is used to normalize the direction of each contour. The normalization process includes the outer contour in a counterclockwise direction and the inner contour in a clockwise direction. The unit performs segment / point matching search on the contour of one layer and the corresponding contour of the next layer to find the tangent vector between each point of the contour and the lower layer contour. The contour tangent vector is used to determine whether the contour at this point is an extensional structure. The printhead axial direction and position determination unit is used to analyze the contour and the features of the next layer contour to find the inflection points of each contour and perform matching analysis. If no match can be found, the intersection point is obtained by drawing a perpendicular bisector from the contour vertex. If there is no intersection point, the nearest point is obtained and the direction of the line connecting the intersection point or the nearest point and the vertex is used as the direction of the tangent vector. If a match can be found, the contour and the reference contour are divided into multiple corresponding segments. At the inflection point, the inflection point is used as the basis for the direction of the tangent vector. For the remaining points, the intersection point of the perpendicular bisector of the contour vertex and the reference contour or the nearest point is found in each corresponding segment as the basis for the direction of the tangent vector. The tangent vector is the axial direction of the printhead, and the contour point is the position of the printhead. The adding circle unit is used to determine the need to increase the additive allowance and to add circles to the contour; the adding circle process includes offsetting the contour outward from the solid based on the original contour to form a multi-circle contour; The vector tilting unit is used to determine that the outermost contour belongs to the extension structure, and then the contour is tilted according to the actual cutting edge tangent vector. The code output unit is used to output the original filling information and the modified contour information as additive manufacturing instruction codes based on the characteristics of the NC device.

7. An additive manufacturing contour processing device, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the additive manufacturing process contour processing method according to any one of claims 1-5 according to the instructions in the program code.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the additive manufacturing contour processing method according to any one of claims 1-5.

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