Polymer printing layered slice real-time simulation method based on digital twinning

Abstract

The application discloses a high polymer printing layered slice real-time simulation method based on digital twinning, relates to the technical field of 3D printing layered slice detection, and comprises the following steps: constructing a digital twinning model of a 3D printer; obtaining model layering based on layered slice parameters; the digital twinning model performs virtual printing on a 3D model based on the model layering, and the printing result is extracted after each model layering; identifying the parameter area in the printing result and judging whether the printing result has defects; if the printing result has defects, the defects are subjected to parameter calibration analysis, and the layered slice parameters or physical parameters of the defects are calibrated separately; the application is used to solve the problems that the existing 3D printing layered slice detection technology cannot predict defects occurring in the printing process and intelligently adjust the defects, and the printing process is prone to causing material waste and excessively relying on manual adjustment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing layered slice detection, in particular to a high polymer printing layered slice real-time simulation method based on digital twinning. BACKGROUND

[0002] 3D printing layered slice detection technology refers to a technology of automatically analyzing, verifying and monitoring each layer to be printed or each layer of entity being printed in the 3D printing process. The core purpose is to find design errors, process problems or material defects that may cause printing failure in advance before printing starts or during printing, so as to avoid printing failure, save time and material cost.

[0003] The existing 3D printing layered slice detection technology usually needs to print the model to determine whether defects will occur in the printing process. This method will cause excessive waste of materials. When the printed model has defects, the existing 3D printing layered slice detection technology usually needs to manually adjust various parameters during printing. Because the types of defects are different, the parameters to be adjusted are also different. The printer needs to judge and modify by himself. The existing 3D printing layered slice detection technology cannot intelligently adjust based on the type of defect, cannot predict the defect in the printing process and intelligently adjust the defect, and causes problems of easy material waste and excessive dependence on manual adjustment in the printing process. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the prior art. A digital twinning model of a 3D printer is constructed. Physical parameters of the 3D printer are input into the digital twinning model. Then, a user inputs a 3D model and configures layered slice parameters. The 3D model is virtually printed based on the layered slice parameters. A printing result is extracted after printing each layered slice of the 3D model. Each layered slice of the 3D model corresponds to a printing result. The printing result is identified. A parameter region is extracted. The parameter region is corrected and evaluated. Whether the printing result has defects is determined. If the printing result has defects, the parameter calibration analysis of the defective part is performed. The layered slice parameters or physical parameters of the defective part are calibrated separately. The problem that the existing 3D printing layered slice detection technology cannot predict the defect in the printing process and intelligently adjust the defect, which causes easy material waste and excessive dependence on manual adjustment in the printing process, is solved.

[0005] To achieve the above-mentioned purpose, the present application provides a high polymer printing layered slice real-time simulation method based on digital twinning, which comprises the following steps:

[0006] Construct a digital twin model of a 3D printer and input the physical parameters of the 3D printer into the digital twin model;

[0007] After the user inputs a 3D model, they configure the layering and slicing parameters, and the model is layered based on the layering and slicing parameters.

[0008] Digital twin models are based on model layering to virtually print 3D models. Each time a model layer is printed, the printing result is extracted, and each model layer corresponds to a printing result.

[0009] The print results are identified and evaluated, including identifying parameter areas and determining whether there are any defects in the print results.

[0010] If there are defects in the printed results, parameter calibration analysis is performed on the defective parts, and the layer slicing parameters or physical parameters of the defective parts are calibrated separately.

[0011] Furthermore, the physical parameters include mechanical parameters, thermal parameters, and material parameters.

[0012] Furthermore, after the user inputs the 3D model, they configure the layering and slicing parameters. The process of obtaining model layers based on these parameters includes the following sub-steps:

[0013] Users input the completed 3D model into the digital twin model;

[0014] Obtain the layered slicing parameters configured by the user, including layer height parameters, fill parameters, and wall thickness parameters;

[0015] Based on layer height, fill, and wall thickness parameters, the 3D model is divided into different model layers, which are labeled as ML in order from bottom to top. n , where n is a non-zero natural number and n is the index of ML.

[0016] Furthermore, the virtual printing of the 3D model based on the model's layering in the digital twin model includes the following sub-steps:

[0017] 3D print ML1, label the printed model as PM1, construct a three-dimensional coordinate system named the model extraction coordinate system, put PM1 into the model extraction coordinate system, at this time the set of coordinate points belonging to PM1 can be extracted, named the coordinate set, label the coordinate set of PM1 as CS1, and use CS1 as the printing result of ML1, labeled as PR1.

[0018] Starting with n=2, for ML n Perform 3D printing and label the printed model as PM. n PM nPut into the model extraction coordinate system, at this time can extract the coordinate set CS n belongs to PM n , remove the part of CS n belongs to CS n-1 , get the printing result of ML n , marked as PR n ;

[0019] Each extraction of a printing result is performed once to identify and evaluate the printing result, and the next layer of 3D printing is performed after the analysis of the printing result is completed.

[0020] Further, the identification and evaluation of the printing result are performed, the parameter region in the printing result is identified, and it is judged whether the printing result has defects, including the following sub-steps:

[0021] The printing result is identified, and the parameter region is extracted, which is the region controlled by the layered slicing parameters;

[0022] The parameter region is corrected;

[0023] The parameter region is evaluated to determine whether the printing result has defects.

[0024] Further, the identification of the printing result is performed, and the parameter region is extracted, including the following sub-steps:

[0025] The PR n currently analyzed is named as the result to be analyzed, the ML n corresponding to the result to be analyzed is named as the layer to be analyzed, the connected regions in the layer to be analyzed are named as layer sub-regions, each layer sub-region is analyzed independently, and the part of the result to be analyzed corresponding to the layer sub-region is named as the sub-region result;

[0026] The outline of the layer sub-region is named as the region outline, the coordinate points on the region outline are named as the outline points, and the part other than the sub-region result is named as the external region;

[0027] The sub-region result is overlapped with the region outline of the layer sub-region, and is analyzed from a top-down perspective, when any outline point is analyzed, it is named as an analysis point, the outline points adjacent to the analysis point are named as adjacent points, whether the analysis point and the adjacent points are on the same straight line is queried, if yes, a straight line analysis signal is output, if not, a tangent line analysis signal is output;

[0028] If the straight line analysis signal is output, the straight line where the analysis point and the adjacent point are located is named as the analysis line, a ray is constructed perpendicularly to the analysis line with the analysis point as the end point, and is named as the analysis auxiliary line. A coordinate point in the analysis auxiliary line which first contacts the external region is named as the internal mapping point. The internal mapping point of each contour point is analyzed, and the internal contour is composed of all the internal mapping points;

[0029] If the tangent line analysis signal is output, the tangent line at the analysis point is named as the analysis line, and the internal mapping point is analyzed. Finally, the internal contour is obtained.

[0030] The closed region surrounded by the internal contour and the region contour is named as the wall thickness analysis area, and the part in the sub-region result which does not belong to the wall thickness analysis area is named as the filling analysis area. The wall thickness analysis area and the filling analysis area are the parameter regions.

[0031] Further, the correction of the parameter regions includes the following sub-steps:

[0032] The distance between the contour point and the internal mapping point is obtained, and is named as the test length.

[0033] If the internal mapping point is adjacent to the filling analysis area, the internal mapping point is moved in the direction of the contour point until the test length is the wall thickness parameter. The internal mapping points adjacent to the filling analysis area are corrected, and the wall thickness analysis area and the filling analysis area are updated. The parameter regions are re-divided.

[0034] Further, the evaluation of the parameter regions to determine whether the printing result has defects includes the following sub-steps:

[0035] The coordinate points in the sub-region result are named as the result points. The model extraction coordinate system has X axis, Y axis and Z axis, which respectively represent length, width and height. The result points with equal X axis and equal Y axis are summarized as a group of homologous points. The difference between the minimum value and the maximum value of the Z axis in the homologous points is obtained, and is named as the test layer height. The test layer height and the layer height parameter are respectively marked as TFH and PFH. The calculation result of |TFH-PFH| / PFH is named as the layer height error.

[0036] The analysis is performed from the top view. In the analysis process, only the X axis and Y axis dimensions are considered, and the Z axis dimension is not considered. The sub-region result is overlapped with the parameter regions of the layered sub-regions. The result points in the sub-region result which belong to the filling analysis area are removed. The remaining result points are named as the wall thickness analysis points.

[0037] The region composed of the wall thickness analysis points is subjected to contour extraction, and the wall thickness analysis contour is obtained. A ray is drawn through the contour point with the internal mapping point as the end point, and is named as the wall thickness auxiliary line. The intersection point of the wall thickness auxiliary line and the wall thickness analysis contour is named as the external contour point. The distance between the external contour point and the internal mapping point is obtained, and is named as the test wall thickness.

[0038] The test wall thickness and the wall thickness parameter are respectively marked as TWT and PWT, |TWT-PWT| / PWT is calculated, and the calculation result is named as wall thickness error;

[0039] The printing precision of the 3D printer is obtained, which is the maximum error allowed by the 3D printer, and it is judged whether the layer height error and the wall thickness error are less than or equal to the printing precision, if yes, a printing normal signal is output, if not, a printing abnormal signal is output;

[0040] If the printing abnormal signal is output, the sub-region result is marked as having defects, and the layer height error and the wall thickness error greater than the printing precision are named as over-limit error.

[0041] Further, if the printing result has defects, the parameter calibration analysis is performed on the defect part, and the slicing parameters or physical parameters of the defect part are calibrated separately, including the following sub-steps:

[0042] The wall thickness auxiliary line corresponding to the over-limit error is named as over-limit wall thickness line, and the face composed of the continuous adjacent over-limit wall thickness lines is named as defect part;

[0043] The coordinate points of the defect part are named as defect points, and the defect points with equal X-axis and equal Y-axis are summarized as a group of homologous defect groups;

[0044] The minimum and maximum values of the Z-axis in the homologous defect group are obtained and marked as MinZ and MaxZ respectively, the MinZ and MaxZ of each group of homologous defect groups are obtained, if all MinZ are equal and all MaxZ are equal, a slicing parameter error signal is output, otherwise a printing parameter error signal is output;

[0045] Based on the output slicing parameter error signal or printing parameter error signal, the slicing parameters or physical parameters are calibrated separately.

[0046] Further, based on the output slicing parameter error signal or printing parameter error signal, the slicing parameters or physical parameters are calibrated separately, including the following sub-steps:

[0047] If the output slice parameter error signal is output, the layering slice parameters of the defective part are adjusted so that the layer height error and the wall thickness error are less than or equal to the printing precision, if the test wall thickness is less than the wall thickness parameter, the wall thickness parameter of the defective part is increased alone, if the test wall thickness is greater than the wall thickness parameter, the wall thickness parameter of the defective part is reduced alone, if the test layer height is less than the layer height parameter, the layer height parameter of the defective part is increased alone, if the test layer height is greater than the layer height parameter, the layer height parameter of the defective part is reduced alone, the sub-region result is reprinted and whether the wall thickness error and the layer height error are less than or equal to the printing precision is reanalyzed, and when the wall thickness error and the layer height error are calculated, the wall thickness parameter and the layer height parameter set by the user are calculated, rather than the increased or reduced wall thickness parameter and the layer height parameter;

[0048] When the printing parameter error signal is output, the layer height error is greater than the printing precision, if the test layer height is greater than the layer height parameter, the power of the cooling fan is reduced to increase the material cooling time, if the test layer height is less than the layer height parameter, the power of the cooling fan is increased to reduce the material cooling time, when the power of the cooling fan is reduced or increased, the sub-region result is repeatedly regenerated until the wall thickness error and the layer height error are less than or equal to the printing precision.

[0049] The present application has the following advantages: the present application constructs a digital twin model of a 3D printer, inputs physical parameters of the 3D printer into the digital twin model, then a user inputs a 3D model and configures layering slice parameters, slices the model layering based on the layering slice parameters, the digital twin model virtually prints the 3D model based on the model layering, extracts a printing result after printing each model layering, and each model layering corresponds to a printing result, which has the advantages that the 3D printing result can be simulated layer by layer, so that the model layering can be analyzed for defects, and the actual printing process can be pre-adjusted according to the simulation result, thereby improving the effectiveness of 3D printing layering slice detection and saving materials.

[0050] The present application has the following advantages: the present application constructs a digital twin model of a 3D printer, inputs physical parameters of the 3D printer into the digital twin model, then a user inputs a 3D model and configures layering slice parameters, slices the model layering based on the layering slice parameters, the digital twin model virtually prints the 3D model based on the model layering, extracts a printing result after printing each model layering, and each model layering corresponds to a printing result, which has the advantages that the 3D printing result can be simulated layer by layer, so that the model layering can be analyzed for defects, and the actual printing process can be pre-adjusted according to the simulation result, thereby improving the effectiveness of 3D printing layering slice detection and saving materials. BRIEF DESCRIPTION OF DRAWINGS

[0051] Figure 1 The present application has the following advantages: the present application constructs a digital twin model of a 3D printer, inputs physical parameters of the 3D printer into the digital twin model, then a user inputs a 3D model and configures layering slice parameters, slices the model layering based on the layering slice parameters, the digital twin model virtually prints the 3D model based on the model layering, extracts a printing result after printing each model layering, and each model layering corresponds to a printing result, which has the advantages that the 3D printing result can be simulated layer by layer, so that the model layering can be analyzed for defects, and the actual printing process can be pre-adjusted according to the simulation result, thereby improving the effectiveness of 3D printing layering slice detection and saving materials.

[0052] Figure 2 a schematic diagram of a region profile of the present application;

[0053] Figure 3 a schematic diagram of a sub-region result of the present application;

[0054] Figure 4 a schematic diagram of an analysis point and adjacent points of the present application;

[0055] Figure 5 a schematic diagram of an analysis auxiliary line and internal mapping points of the present application;

[0056] Figure 6 a schematic diagram of a wall thickness analysis region and a filling analysis region of the present application;

[0057] Figure 7 a schematic diagram of a parameter region of the present application. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0059] Embodiment 1, please refer to Figure 1 As shown in the figure, the present application provides a high polymer printing layered slicing real-time simulation method based on digital twinning, including the following steps:

[0060] Step S1, a digital twinning model of a 3D printer is constructed, and physical parameters of the 3D printer are input into the digital twinning model; the physical parameters include mechanical parameters, thermal parameters and material parameters;

[0061] In the specific implementation, the digital twinning model of the 3D printer is constructed by using the existing digital twinning technology, and the mechanical parameters, the thermal parameters and the material parameters are all parameters required for constructing the digital twinning model, which are not specifically described in this embodiment.

[0062] Step S2, after a user inputs a 3D model, layered slicing parameters are configured, and the model is layered based on the layered slicing parameters; step S2 includes the following sub-steps:

[0063] Step S201, the user inputs the constructed 3D model into the digital twinning model;

[0064] Step S202, the layered slicing parameters configured by the user are obtained, and the layered slicing parameters include layer height parameters, filling parameters and wall thickness parameters;

[0065] Step S203: Based on the layer height parameter, fill parameter, and wall thickness parameter, the 3D model is divided into different model layers, and the model layers are labeled as ML in order from bottom to top. n , where n is a non-zero natural number and n is the index of ML;

[0066] In practice, the 3D model is sliced ​​into layers using existing slicing software, which will not be described in detail in this embodiment. The layer height, fill, and wall thickness parameters are obtained as 0.2mm, 20%, and 1.2mm, respectively. When printing a 3D model with a height of 10cm, the 3D model needs to be divided into 500 layers, labeled from bottom to top to obtain the ML layer. n , 1≤n≤500.

[0067] Step S3: The digital twin model performs virtual printing of the 3D model based on model layering. The printing result is extracted after each layer is printed, with each layer corresponding to one printing result. Step S3 includes the following sub-steps:

[0068] Step S301: 3D print ML1, mark the printed model as PM1, construct a three-dimensional coordinate system named the model extraction coordinate system, put PM1 into the model extraction coordinate system, at this time the set of coordinate points belonging to PM1 can be extracted, named the coordinate set, mark the coordinate set of PM1 as CS1, and use CS1 as the printing result of ML1, marked as PR1.

[0069] Step S302, starting with n=2, for ML n Perform 3D printing and label the printed model as PM. n PM n When placed into the model extraction coordinate system, the part belonging to PM can be extracted. n coordinate set CS n Remove CS n China belongs to CS n-1 The part that yields ML n The printed result is marked as PR. n ;

[0070] Step S303: Each time a print result is extracted, the print result is identified and evaluated once. After the analysis of the print result is completed, the next layer of 3D printing is performed.

[0071] In practice, since this is the first 3D printing operation on ML1, the printed result is the final result for ML1. Subsequent 3D printing operations on ML1 will then be considered the final result. n When printing, since printing has already been performed, the previous print results need to be discarded in this print run. CS n-1This refers to the coordinate set that already existed before this printing. Removing this set yields the new coordinate set added during this printing, which is ML. n The printing results can be obtained by repeating this process for each ML layer. n Print result PR n Each print is performed on top of an already printed model, rather than printing each layer independently. This is because printing on top of an already printed model involves the adhesion between materials and the gravitational influence of some suspended protrusions.

[0072] Step S4 involves identifying and evaluating the printed results, identifying parameter areas in the printed results, and determining whether there are any defects in the printed results. Step S4 includes the following sub-steps:

[0073] Step S401: Identify the printing results and extract the parameter region, which is the region controlled by the layer slicing parameters;

[0074] Step S401 includes the following sub-steps:

[0075] Step S401.1, transfer the currently analyzed PR n Name it the result to be analyzed, and assign the corresponding ML to the result to be analyzed. n Name it the layer to be analyzed, name the connected regions in the layer to be analyzed as the layer sub-regions, analyze each layer sub-region independently, and name the part of the layer sub-region in the analysis results as the sub-region results;

[0076] Please see Figures 2-3 As shown, in step S401.2, the outline of the layered sub-region is named the region outline, the coordinate points on the region outline are named the outline points, and the part outside the sub-region result is named the outer region.

[0077] In practice, regions that are not connected within the same hierarchical model are considered different hierarchical sub-regions. Assuming the outline of a certain region and the corresponding sub-region results are as follows... Figure 2 as well as Figure 3 As shown, the analysis is performed from a top-down perspective, considering only the X and Y axes and ignoring the Z axis. Since the analysis is conducted within a digital twin model, the simulated printing results can be directly placed into a 3D coordinate system for analysis; therefore, the contour points and all subsequent coordinate points can be directly obtained. The outer region is... Figure 3 The white and dark gray areas in the image represent the sub-region results.

[0078] Please see Figure 4As shown, in step S401.3, the sub-region result is overlaid with the region contour of the layered sub-region and analyzed from a top-down perspective. When analyzing any contour point, it is named the analysis point and the contour point adjacent to the analysis point is named the adjacent point. The analysis point and the adjacent point are checked to see if they are on the same straight line. If they are, the straight line analysis signal is output; if not, the tangent analysis signal is output.

[0079] In practice, when overlaying the region contours of sub-region results and hierarchical sub-regions, the actual process involves overlaying the region contours of the hierarchical sub-regions onto the contours of the sub-region results. This is done because the region contours represent the ideal ML (Multi-Layered Machining) contours. n If the outline of the printed sub-region is used directly for analysis, it cannot be guaranteed that the sub-region result meets the appearance requirements of the layered sub-region. Therefore, the analysis is based on the outline of the layered sub-region. Figure 4 Taking the analysis point and its adjacent points as an example, since the coordinate points are very small and cannot be viewed visually, this embodiment magnifies the coordinate points so that the analysis point and its adjacent points can be observed. Figure 4 The white dots in the diagram represent the analysis points, and the black dots represent adjacent points. Figure 4 It is easy to see that the analysis point and its adjacent points are on the same straight line, so the output is a straight line analysis signal;

[0080] Please see Figure 5 As shown, in step S401.4, if a straight line analysis signal is output, the straight line where the analysis point and its adjacent points are located is named the analysis line. A ray is constructed perpendicular to the analysis line with the analysis point as the endpoint and named the analysis auxiliary line. The coordinate point of the analysis auxiliary line that first contacts the external area is named the internal mapping point. The internal mapping point of each contour point is analyzed, and the internal contour is formed by all the internal mapping points.

[0081] Step S401.5: If the output tangent analysis signal is obtained, the tangent at the analysis point is named the analysis line and the internal mapping point is analyzed to finally obtain the internal contour.

[0082] Please see Figure 6 As shown, in step S401.6, the closed area enclosed by the inner contour and the region contour is named the wall thickness analysis area, and the part of the sub-region result that does not belong to the wall thickness analysis area is named the filling analysis area. The wall thickness analysis area and the filling analysis area are the parameter areas.

[0083] In practice, if a straight line analysis signal is output, then the analysis auxiliary line is drawn as follows: Figure 5 As shown, Figure 5The dashed line in the figure is the analysis auxiliary line, and the gray dot on the dashed line is the internal mapping point of the analysis point. The internal contour is composed of all internal mapping points. Since the 3D printed model has a wall thickness, the printing result actually has an internal contour and an external contour. The internal contour is the internal contour, and the external contour is the area contour. The straight line analysis signal is suitable for 3D models with regular shapes, and the tangent line analysis signal is suitable for 3D models without regular shapes. The wall thickness analysis area and the filling analysis area are finally obtained through analysis, as shown in Figure 6 , wherein the gray part is the wall thickness analysis area, and the black part is the filling analysis area.

[0084] Step S402, correcting the parameter area;

[0085] Step S402 includes the following sub-steps:

[0086] Step S402.1, obtaining the distance between the contour point and the internal mapping point, named as test length;

[0087] Please refer to Figure 7 , step S402.2, if the internal mapping point is adjacent to the filling analysis area, the internal mapping point is moved to the contour point direction until the test length is the wall thickness parameter. Correct all internal mapping points adjacent to the filling analysis area and update the wall thickness analysis area and the filling analysis area, and re-divide the parameter area;

[0088] In the specific implementation, when judging whether the internal mapping point is adjacent to the filling analysis area, not a single point is judged, but the face composed of the analysis auxiliary line with test length exceeding the wall thickness parameter and continuous adjacent is analyzed. In the embodiment, the face composed of the analysis auxiliary line with test length exceeding the wall thickness parameter and continuous adjacent is named as abnormal face. It is judged whether the abnormal face is adjacent to the filling analysis area. If the abnormal face is adjacent to the filling analysis area, it means that the abnormal face actually belongs to the filling analysis area, and the abnormal face can be directly divided into the filling analysis area. The corrected wall thickness analysis area and the filling analysis area are shown in Figure 7 , the parameter area is the wall thickness analysis area and the filling analysis area.

[0089] Step S403, evaluating the parameter area to determine whether the printing result has defects;

[0090] Step S403 includes the following sub-steps:

[0091] Step S403.1, name the coordinate points in the sub-region result as result points, the model extraction coordinate system has X-axis, Y-axis and Z-axis, which respectively represent length, width and height, the result points with equal X-axis and equal Y-axis are summarized as a group of homologous points, the difference between the minimum value and the maximum value of the Z-axis in the homologous points is obtained, and is named as test layer height, the test layer height and the layer height parameter are respectively marked as TFH and PFH, and the calculation result is named as layer height error;

[0092] In a specific implementation, the homologous points are result points in a vertical direction, and the difference between the minimum value and the maximum value of the Z-axis of the homologous points represents the layer height at the current X-axis and Y-axis values, and the test layer height TFH is 0.21 mm, and the layer height parameter PFH is 0.2 mm, and the layer height error is 0.05, which is calculated. Since the 3D printer has the highest precision, it can theoretically tolerate a certain error, so it is necessary to calculate the layer height error and the wall thickness error. In fact, when analyzing the filling parameter, it is only necessary to calculate whether the ratio of the total area of the filling analysis area of each layer ML n to the total area of the region contour is equal to the filling parameter. 3D printing usually does not require high precision when filling the model, so the analysis of the filling parameter is not specifically described in this embodiment.

[0093] Step S403.2, analyze from the top-down perspective, only consider the X-axis and Y-axis dimensions, and do not consider the Z-axis dimension, overlap the sub-region result and the parameter region of the layered sub-region, remove the result points in the sub-region result that belong to the filling analysis area, and name the remaining result points as wall thickness analysis points;

[0094] Step S403.3, perform contour extraction on the region composed of the wall thickness analysis points to obtain a wall thickness analysis contour, draw a ray through the contour point with the internal mapping point as the end point, and name it as a wall thickness auxiliary line. Obtain the intersection point of the wall thickness auxiliary line and the wall thickness analysis contour, and name it as an external contour point. Obtain the distance between the external contour point and the internal mapping point, and name it as a test wall thickness;

[0095] Step S403.4, mark the test wall thickness and the wall thickness parameter as TWT and PWT respectively, calculate |TWT-PWT| / PWT, and name the calculation result as wall thickness error;

[0096] In a specific implementation, the wall thickness analysis points are obtained after removing the result points in the sub-region result that belong to the filling analysis area. The wall thickness analysis contour is actually the outermost contour of the wall thickness analysis area. The external contour point and the internal contour point are the points corresponding to the contour points after adding the wall thickness parameter on the outer contour and the inner contour. The distance between them is the wall thickness. Thus, the test wall thickness is 0.16 mm, and the wall thickness error is 0.34, which is calculated. The calculation result is rounded to two decimal places.

[0097] Step S403.5, the printing precision of the 3D printer is obtained, the printing precision is the maximum error allowed by the 3D printer, it is judged whether the layer height error and the wall thickness error are less than or equal to the printing precision, if yes, a printing normal signal is output, if not, a printing abnormal signal is output;

[0098] Step S403.6, if the printing abnormal signal is output, the sub-region result is marked as having defects, and the layer height error and the wall thickness error greater than the printing precision are named as over-limit errors;

[0099] In a specific implementation, the printing precision is a device parameter of the 3D printer, which can be directly obtained. The printing precision obtained is 0.05, the wall thickness error is greater than the printing precision by comparison, the printing abnormal signal is output, and the over-limit error is 0.34.

[0100] Step S5, if the printing result has defects, the parameter calibration analysis is performed on the defect part, and the layering slicing parameters or physical parameters of the defect part are calibrated separately; step S5 includes the following sub-steps:

[0101] Step S501, the wall thickness auxiliary line corresponding to the over-limit error is named as an over-limit wall thickness line, and the face composed of the continuous adjacent over-limit wall thickness lines is named as a defect part;

[0102] In a specific implementation, generally, if there is an over-limit error, the wall thickness error greater than the printing precision exists, because if the test layer height is higher than the layer height parameter, it means that the material cools too quickly and is fixed before reaching the ideal shape, and if the test layer height is lower than the layer height parameter, it means that the material cools too slowly and the material overflows around, both of which will cause the test wall thickness to deviate from the wall thickness parameter. Therefore, the defect part can be obtained based on the wall thickness auxiliary line of the output over-limit error, if the defect part cannot be found, it is determined that the layer height parameter at the same site corresponding to the over-limit error is configured incorrectly, otherwise, the defect part exists.

[0103] Step S502, the coordinate points of the defect part are named as defect points, and the defect points with equal X-axis and equal Y-axis are summarized as a same-site defect group;

[0104] Step S503, the minimum value and the maximum value of the Z-axis in the same-site defect group are obtained and are marked as MinZ and MaxZ respectively, the MinZ and the MaxZ of each same-site defect group are obtained, if all the MinZ are equal and all the MaxZ are equal, a slicing parameter error signal is output, otherwise, a printing parameter error signal is output;

[0105] In a specific implementation, it is assumed that there are three groups of same defects, and their MinZ is 0.21 and MaxZ is 0.42, which represents that their test layer height is the same. At this time, the defect part must be a flat and regular model, that is, the defect here is caused by the error of the slicing parameter configuration of the layered slice here. The printing parameter controls the heating and cooling of the material. If the printing parameter configuration is incorrect, the surface of the defect part cannot be flat. Therefore, it is judged whether the slicing parameter or the printing parameter needs to be adjusted.

[0106] Step S504, calibrating the slicing parameter or the physical parameter based on the output slicing parameter error signal or the printing parameter error signal;

[0107] Step S504 includes the following sub-steps:

[0108] Step S504.1, if the slicing parameter error signal is output, the slicing parameter of the defect part is adjusted so that the layer height error and the wall thickness error are less than or equal to the printing precision. If the test wall thickness is less than the wall thickness parameter, the wall thickness parameter of the defect part is increased alone. If the test wall thickness is greater than the wall thickness parameter, the wall thickness parameter of the defect part is reduced alone. If the test layer height is less than the layer height parameter, the layer height parameter of the defect part is increased alone. If the test layer height is greater than the layer height parameter, the layer height parameter of the defect part is reduced alone. The sub-area result is reprinted and whether the wall thickness error and the layer height error are less than or equal to the printing precision is reanalyzed. When calculating the wall thickness error and the layer height error, the wall thickness parameter and the layer height parameter set by the user are calculated, not the increased or reduced wall thickness parameter and layer height parameter.

[0109] Step S504.2, when the printing parameter error signal is output, the layer height error is greater than the printing precision. If the test layer height is greater than the layer height parameter, the power of the cooling fan is reduced to increase the material cooling time. If the test layer height is less than the layer height parameter, the power of the cooling fan is increased to reduce the material cooling time. When the power of the cooling fan is reduced or increased, the sub-area result is repeatedly regenerated until the wall thickness error and the layer height error are less than or equal to the printing precision.

[0110] In a specific implementation, when the layer height parameter of the defect part or the power of the cooling fan is adjusted, the adjustment amplitude is small each time, usually 1% to 5%. The adjustment can be completed through multiple adjustment analyses.

[0111] In embodiment 2, the electronic device can include a processor, a communication interface, a memory, and a communication bus. The processor, the communication interface, and the memory can communicate with each other through the communication bus. The memory stores computer readable instructions. The processor can invoke the instructions in the memory. When the computer readable instructions are executed by the processor, the steps in the method for real-time simulation of polymer printing layer slicing based on digital twinning are executed to achieve the following functions: constructing a digital twinning model of a 3D printer; slicing the model based on layer slicing parameters to obtain model layers; virtually printing the 3D model based on the model layers by the digital twinning model, and extracting the printing result after each model layer is printed; identifying the parameter area in the printing result and determining whether the printing result has defects; and if the printing result has defects, performing parameter calibration analysis on the defective part, and separately calibrating the layer slicing parameters or physical parameters of the defective part.

[0112] In addition, the logical instructions in the memory described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0113] In embodiment 3, the present application further provides a computer program product, which includes a computer program stored on a computer readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the method for real-time simulation of polymer printing layer slicing based on digital twinning. The method includes: constructing a digital twinning model of a 3D printer; slicing the model based on layer slicing parameters to obtain model layers; virtually printing the 3D model based on the model layers by the digital twinning model, and extracting the printing result after each model layer is printed; identifying the parameter area in the printing result and determining whether the printing result has defects; and if the printing result has defects, performing parameter calibration analysis on the defective part, and separately calibrating the layer slicing parameters or physical parameters of the defective part.

[0114] Embodiment 4, the application also provides a computer readable storage medium, and the application provides a storage medium having a computer program stored thereon, the computer program is executed by a processor to run the steps in the above polymer printing layer slicing real-time simulation method based on digital twinning to realize the following functions: constructing a digital twinning model of a 3D printer; obtaining model layers based on layer slicing parameters; the digital twinning model performs virtual printing on the 3D model based on the model layers, and the printing result is extracted after each model layer is printed; identifying the parameter area in the printing result and determining whether the printing result has defects; if the printing result has defects, the parameter calibration analysis is performed on the defect part, and the layer slicing parameters or physical parameters of the defect part are calibrated separately.

[0115] Through the above description of the embodiments, the embodiments of the application can be provided as a method, a system or a computer program product. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, etc., 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 method described in each embodiment or some parts of the embodiment.

[0116] In the embodiments provided by the present application, it should be understood that the disclosed system or method can be implemented in other ways. The above described embodiments are merely illustrative. For example, the division of the modules or units is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of modules or units can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the modules or units shown or discussed can be indirect coupling or communication connection through some communication interfaces, and electrical, mechanical or other forms.

[0117] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for real-time simulation of polymer printing layer slicing based on digital twinning, characterized in that, The method comprises the following steps: constructing a digital twin model of a 3D printer, and inputting physical parameters of the 3D printer into the digital twin model; after a user inputs a 3D model, configuring slicing parameters, slicing the 3D model based on the slicing parameters to obtain model layers; the digital twin model virtually prints the 3D model based on the model layers, extracts a printing result after printing each model layer, and each model layer corresponds to a printing result; identifying and evaluating the printing result, identifying a parameter region in the printing result, judging whether the printing result has defects, evaluating the parameter region, and judging whether the printing result has defects; if the printing result has defects, performing parameter calibration analysis on the defective part, and separately calibrating slicing parameters or physical parameters of the defective part; the step of evaluating the parameter region to judge whether the printing result has defects comprises the following sub-steps: naming coordinate points in the sub-region result as result points, the model extraction coordinate system has X, Y and Z axes, representing length, width and height respectively, grouping result points with equal X and Y axes as a group of homologous points, obtaining the difference between the minimum value and the maximum value of the Z axis in the homologous points, naming the difference as test layer height, marking the test layer height and layer height parameters as TFH and PFH respectively, calculating |TFH-PFH| / PFH, and naming the calculation result as layer height error; analyzing from a top-down perspective, only considering X and Y axis dimensions and not considering Z axis dimension, overlapping the sub-region result and the parameter region of the slicing sub-region, removing result points in the sub-region result that belong to the filling analysis area, and naming the remaining result points as wall thickness analysis points; performing contour extraction on the region composed of the wall thickness analysis points to obtain a wall thickness analysis contour, drawing a ray through the contour point with the internal mapping point as the end point, naming the ray as a wall thickness auxiliary line, obtaining the intersection point of the wall thickness auxiliary line and the wall thickness analysis contour, naming the intersection point as an external contour point, and obtaining the distance between the external contour point and the internal mapping point, naming the distance as test wall thickness; marking the test wall thickness and the wall thickness parameter as TWT and PWT respectively, calculating |TWT-PWT| / PWT, and naming the calculation result as wall thickness error; obtaining the printing precision of the 3D printer, the printing precision being the maximum error allowed by the 3D printer, judging whether the layer height error and the wall thickness error are less than or equal to the printing precision, outputting a normal printing signal if yes, and outputting an abnormal printing signal if no; if the abnormal printing signal is output, marking that the sub-region result has defects, and naming the layer height error and the wall thickness error greater than the printing precision as over-limit errors; if the printing result has defects, performing parameter calibration analysis on the defective part, and separately calibrating slicing parameters or physical parameters of the defective part, which comprises the following sub-steps: naming the wall thickness auxiliary line corresponding to the over-limit error as an over-limit wall thickness line, and naming the face composed of continuous adjacent over-limit wall thickness lines as a defective part; naming coordinate points of the defective part as defect points, and grouping defect points with equal X and Y axes as a group of homologous defect groups. Obtaining the minimum and maximum values of the Z axis in the same defect group, respectively marked as MinZ and MaxZ, obtaining the MinZ and MaxZ of each same defect group, if all MinZ are equal and all MaxZ are equal, outputting a slice parameter error signal, otherwise outputting a printing parameter error signal; Calibrating the slicing parameters or physical parameters separately based on the output slice parameter error signal or printing parameter error signal; The calibration of the slicing parameters or physical parameters based on the output slice parameter error signal or printing parameter error signal includes the following sub-steps: If the slice parameter error signal is output, the slicing parameters of the defect part are adjusted so that the layer height error and the wall thickness error are less than or equal to the printing precision, if the test wall thickness is less than the wall thickness parameter, the wall thickness parameter of the defect part is increased alone, if the test wall thickness is greater than the wall thickness parameter, the wall thickness parameter of the defect part is reduced alone, if the test layer height is less than the layer height parameter, the layer height parameter of the defect part is increased alone, if the test layer height is greater than the layer height parameter, the layer height parameter of the defect part is reduced alone, the sub-region result is reprinted and whether the wall thickness error and the layer height error are less than or equal to the printing precision is reanalyzed, and when calculating the wall thickness error and the layer height error, the wall thickness parameter and the layer height parameter set by the user are calculated, rather than the increased or reduced wall thickness parameter and layer height parameter; When the printing parameter error signal is output, the layer height error is greater than the printing precision, if the test layer height is greater than the layer height parameter, the power of the cooling fan is reduced to increase the material cooling time, if the test layer height is less than the layer height parameter, the power of the cooling fan is increased to reduce the material cooling time, when the power of the cooling fan is reduced or increased, the sub-region result is repeatedly regenerated until the wall thickness error and the layer height error are less than or equal to the printing precision.

2. The digital-twin-based real-time simulation method for polymer printing layer slicing according to claim 1, wherein, The physical parameters include mechanical parameters, thermal parameters and material parameters.

3. The digital-twin-based real-time simulation method for polymer printing layer-by-layer slicing according to claim 2, wherein, After the user inputs the 3D model, the slicing parameters are configured, and the model slicing based on the slicing parameters includes the following sub-steps: The user inputs the built 3D model into the digital twin model; Obtaining the slicing parameters configured by the user, the slicing parameters including the layer height parameter, the filling parameter and the wall thickness parameter; The 3D model is divided into different model layers based on the layer height parameter, the filling parameter, and the wall thickness parameter, and the model layers are marked as ML in order from bottom to top n wherein n is a non-zero natural number and n is the serial number of the ML.

4. The digital-twin-based real-time simulation method for polymer printing layer-by-layer slicing according to claim 3, wherein, The virtual printing of the 3D model based on the model slicing by the digital twin model includes the following sub-steps: 3D printing ML1, marking the printed model as PM1, constructing a three-dimensional coordinate system named model extraction coordinate system, and placing PM1 into the model extraction coordinate system, at this time, the coordinate point set belonging to PM1 can be extracted, named as coordinate set, marking the coordinate set of PM1 as CS1, taking CS1 as the printing result of ML1, and marking it as PR1; Start with n = 2, 3D print ML n , mark the printed model as PM n , put PM n into the model extraction coordinate system, at this time the coordinate set CS n belonging to PM n can be extracted, eliminate the part in CS n that belongs to CS n-1 , get the printing result of ML n , mark it as PR n ; The identification and evaluation of the printing result are performed once for each extracted printing result, and the 3D printing of the next layer is performed after the analysis of the current printing result is completed.

5. The digital-twin-based real-time simulation method for polymer printing layer-by-layer slicing according to claim 4, wherein, The identification and evaluation of the printing result, the identification of the parameter region in the printing result and the judgment of whether the printing result has defects include the following sub-steps: The printing result is recognized to extract a parameter region, which is a region controlled by the slicing parameters; The parameter region is corrected.

6. The digital-twin-based real-time simulation method for polymer printing layer-by-layer slicing according to claim 5, wherein, The printing result is recognized to extract a parameter region, which includes the following sub-steps: The PR currently analyzed is named as a result to be analyzed n The ML corresponding to the result to be analyzed is named as a result to be analyzed layer, the connected regions in the result to be analyzed layer are named as layer sub-regions, each layer sub-region is independently analyzed, and the part corresponding to the layer sub-region in the result to be analyzed is named as a sub-region result n The layer sub-region is named as a result to be analyzed layer, the connected regions in the result to be analyzed layer are named as layer sub-regions, each layer sub-region is independently analyzed, and the part corresponding to the layer sub-region in the result to be analyzed is named as a sub-region result The outline of the layered sub-region is named as a region outline, the coordinate points on the region outline are named as outline points, and the part other than the sub-region result is named as an external region; The sub-region result is overlapped with the region outline of the layered sub-region to analyze in a top view perspective. When analyzing any outline point, it is named as an analysis point, the outline point adjacent to the analysis point is named as a neighboring point, and whether the analysis point and the neighboring point are on the same straight line is queried. If yes, a straight line analysis signal is output, and if not, a tangent line analysis signal is output; If the straight line analysis signal is output, the straight line where the analysis point and the neighboring point are located is named as an analysis line, a ray is constructed perpendicular to the analysis line with the analysis point as an end point, and is named as an analysis auxiliary line. The coordinate point where the analysis auxiliary line first contacts the external region is named as an internal mapping point, and the internal mapping point of each outline point is analyzed. The internal mapping points form an internal outline. If the tangent line analysis signal is output, the tangent line at the analysis point is named as an analysis line, and the internal mapping point is analyzed to finally obtain the internal outline. A closed region surrounded by the internal outline and the region outline is named as a wall thickness analysis area, and the part in the sub-region result other than the wall thickness analysis area is named as a filling analysis area. The wall thickness analysis area and the filling analysis area are the parameter region.

7. The digital-twin-based real-time simulation method for polymer printing layer-by-layer slicing according to claim 6, wherein, The parameter region is corrected, which includes the following sub-steps: The distance between the outline point and the internal mapping point is obtained and is named as a test length; If the internal mapping point is adjacent to the filling analysis area, the internal mapping point is moved in the direction of the outline point until the test length is the wall thickness parameter. The internal mapping points adjacent to the filling analysis area are corrected, and the wall thickness analysis area and the filling analysis area are updated to redivide the parameter region.

Images