Online warping detection method and system based on 3D printing

Abstract

The invention belongs to the technical field of additive manufacturing, and particularly relates to a warping online detection method and system based on 3D printing. An expansion model is arranged around a to-be-printed part model to form a printing model; performing multi-layer 3D printing according to the printing model, and obtaining the height of the expansion model of each printing layer to obtain actual height data; calculating a height difference based on the actual height data and corresponding standard height data to obtain warping data; and controlling the 3D printer to continue or stop 3D printing based on the warping data. Direct failure of part printing after serious buckling deformation during printing can be avoided, the printing success rate can be increased, and the forming quality and precision of a part body are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and in particular relates to a 3D printing-based online warping detection method and system. Background Art

[0002] In the aerospace, shipbuilding and other industrial fields, large-scale complex components are increasingly using complex structural designs and polymer-based composite materials to replace metal materials due to technical requirements such as light weight, high strength and multi-function, so as to obtain lightweight and high-strength functional components. In principle, fused deposition 3D printing technology can realize the integrated forming of complex structures of any size, and is compatible with most 3D printing polymers and composite materials. It is the most suitable manufacturing method for large-scale composite components. However, the serious warping deformation phenomenon of high-performance composite materials represented by polyetheretherketone-based composite materials during the printing process has always been one of the most prominent process difficulties of fused deposition 3D printing.

[0003] The warping deformation of large-scale composite material fused deposition 3D printing is mainly due to the uneven melting and solidification of the material, which causes internal stress in the structure. The anisotropy of 3D printing aggravates the accumulation of internal stress. This deformation is an inherent phenomenon of uneven changes in material morphology and is difficult to avoid completely. Summary of the invention

[0004] Purpose of the invention: The present invention provides an online detection method for warping based on 3D printing, which can solve the technical problem of severe warping deformation during 3D printing of large-size composite materials by fused deposition.

[0005] Technical solution of the present invention: In order to achieve the above-mentioned purpose, in the first aspect, the present disclosure provides an online detection method for warping based on 3D printing, comprising: setting an extended model around the model of a part to be printed to form a printing model; performing multi-layer 3D printing according to the printing model, and obtaining the height of the extended model of each printing layer to obtain actual height data; calculating the height difference based on the actual height data and the corresponding standard height data to obtain warping data; and controlling the 3D printer to continue or stop 3D printing based on the warping data.

[0006] Optionally, the extended model is a model of multiple cross-shaped cylinders; the multiple cross-shaped cylinder models surround the model of the component to be printed; and the cross-section of the cross-shaped cylinder along the plane parallel to the printing base surface is cross-shaped.

[0007] Optionally, the cross-shaped column is divided by the intersection position and includes: a first expansion plate, the first expansion plate is a plate away from the side of the component model to be printed; a second expansion plate, the second expansion plate is a plate perpendicular to the first expansion plate; a third expansion plate, the third expansion plate is a plate perpendicular to the first expansion plate and symmetrical with the second expansion plate along the intersection position; a fourth expansion plate, the fourth expansion plate is a plate close to the side of the component model to be printed, and the fourth expansion plate is used to connect the component model to be printed; the actual height data of the first expansion board, the actual height data of the second expansion board and the actual height data of the third expansion board are respectively calculated with the corresponding standard height data, and the height difference is then quantified and analyzed to obtain warping data.

[0008] Optionally, the actual height data of the first expansion board, the actual height data of the second expansion board, and the actual height data of the third expansion board are respectively calculated with the corresponding standard height data, and the height difference is then quantified and analyzed to obtain the warping data, including: using a feature recognition algorithm to respectively extract the actual height data of the first expansion board, the second expansion board, and the third expansion board; comparing the actual height data with the corresponding standard height data to obtain the height difference; establishing a discrete distribution coordinate system of the height difference based on the height difference; performing fitting operation on discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface; and determining the warping data using the warping deformation distribution surface.

[0009] Optionally, performing a fitting operation on the discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface includes: performing an interpolation fitting operation on the discrete points corresponding to the height difference between the second expansion board and the third expansion board in the discrete distribution coordinate system to obtain a warping deformation distribution curve; and fitting the warping deformation distribution surface based on the discrete points of the height difference of the first expansion board and the warping deformation distribution curve.

[0010] Optionally, determining the warping data using the warping deformation distribution surface includes: calculating the maximum value of the height difference between the actual height data of the i-th layer and the standard height data of the i-th layer to obtain the deformation data of the i-th layer; wherein i is a natural number greater than or equal to 1; and the warping data includes the deformation data.

[0011] Optionally, controlling the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation data of the i-th layer is greater than or equal to a first threshold, stopping 3D printing.

[0012] Optionally, if the deformation data of the i-th layer is less than a first threshold, determining the warping data using the warping deformation distribution surface also includes: based on the warping deformation distribution surface, presetting a data acquisition cycle time; calculating the height difference between the actual height data printed at the initial moment of the n-th cycle and the standard height data at the initial moment of the n-th cycle; calculating the height difference between the actual height data printed at the end moment of the n-th cycle and the standard height data at the end moment of the n-th cycle; calculating the difference in height between the initial moment of the n-th cycle and the end moment of the n-th cycle at the same horizontal and vertical coordinate positions in a discrete distribution coordinate system, taking the maximum difference, and obtaining the deformation increment of the n-th cycle; wherein n is a natural number greater than or equal to 1; and the warping data includes the deformation increment.

[0013] Optionally, controlling the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation increment of the nth cycle is greater than or equal to a second threshold, stopping 3D printing.

[0014] Optionally, if the deformation increment of the i-th layer is less than a second threshold, using the warping deformation distribution surface to determine the warping data also includes: based on the warping deformation distribution surface, calculating the sum of the height differences at the same horizontal and vertical coordinate positions in each period from the m-th period to the n-th period in the discrete distribution coordinate system, taking the minimum cumulative value, and obtaining the cumulative deformation increment; if the cumulative deformation increment is less than a third threshold, continuing 3D printing; if the cumulative deformation increment is greater than or equal to the third threshold, stopping 3D printing; wherein m is a natural number less than n; the warping data includes the cumulative deformation increment.

[0015] According to the specific implementation mode proposed in the specific implementation process of the present invention, in the second aspect, the present disclosure provides an online warping detection system based on 3D printing, including: a modeling unit, the modeling unit is used to set an extended model around the model of the part to be printed to form a printing model; a collection unit, the collection unit is used to obtain the height of the extended model of each printing layer during multi-layer 3D printing, and obtain actual height data; a processing unit, the processing unit is used to calculate the height difference based on the actual height data and the corresponding standard height data to obtain warping data; a control unit, the control unit is used to control the 3D printer to continue or stop 3D printing based on the warping data.

[0016] Compared with the prior art, the technical solution proposed by the present invention has at least the following beneficial effects: the online detection method for warpage proposed in the solution of the present invention is an online detection method for warpage deformation of large-scale high-performance polymer and composite parts in 3D printing, which effectively solves the technical problem of severe warpage deformation during 3D printing of large-scale composite materials by melt deposition; the online detection method for warpage proposed in the specific implementation process of the present invention has low execution cost and wide application range of parts. The present invention can timely discover the serious unevenness of the top surface of the printed structure and the serious deterioration of the adhesion between the bottom and the printing base surface caused by excessive warpage deformation at any time through real-time image acquisition and in-depth analysis of the printed structure, and can detect the severe deterioration of warpage deformation and interlayer splitting and detachment at the same time, and immediately suspend printing, effectively avoiding further damage to the nozzle and the printed structure, a large amount of waste of materials and time, and can continue to print normally after treatment and repair, avoiding the direct failure of part printing after severe warpage deformation when there is no detection, which is conducive to improving the printing success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the online warping detection method based on 3D printing of the present invention;

[0018] Figure 2 A schematic diagram of a 3D printing state of an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of a discrete distribution coordinate system according to an embodiment of the present invention;

[0020] Figure 4 A schematic diagram of a warpage distribution curve of an embodiment of the present invention;

[0021] Figure 5 A schematic diagram of a warping deformation distribution surface according to an embodiment of the present invention;

[0022] Figure 6 A schematic diagram of a cross-shaped column according to an embodiment of the present invention;

[0023] Wherein: 100: cross-shaped column; 110: first expansion board; 120: second expansion board; 130: third expansion board; 140: fourth expansion board; 200: component to be printed; 300: filling part; 400: collection unit. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] According to the specific implementation methods proposed during the specific implementation of the present invention, in the first aspect, the present disclosure provides an online detection method for warping based on 3D printing, which may include: setting an extended model around the model of the component to be printed to form a printing model; performing multi-layer 3D printing according to the printing model, and obtaining the height of the extended model of each printing layer to obtain actual height data; calculating the height difference based on the actual height data and the corresponding standard height data to obtain warping data; and controlling the 3D printer to continue or stop 3D printing based on the warping data.

[0026] The warpage online detection method proposed in the specific implementation process of the present invention is an online detection method for warpage deformation of 3D printed large-size high-performance polymer and composite material parts. The warpage online detection method proposed in the specific implementation process of the present invention has low execution cost and a wide range of parts application. It can avoid the direct failure of part printing after severe warpage deformation during printing, which is conducive to improving the printing success rate and improving the forming quality and precision of the part body.

[0027] The warpage online detection method proposed in the specific implementation process of the present invention belongs to the monitoring of the fused deposition modeling process. Through real-time image acquisition and in-depth analysis of the printed structure, it can timely discover the serious unevenness of the top surface of the printed structure and the serious deterioration of the adhesion between the bottom and the printing base surface caused by excessive warping and deformation at any time. At the same time, it can detect the severe deterioration of warping and deformation and the splitting and detachment between layers, and immediately suspend printing, effectively avoiding further damage to the nozzle and the printed structure, and a large waste of materials and time. After treatment and repair, it can still continue to print normally, avoiding the direct failure of part printing after severe warping and deformation when there is no detection, which is beneficial to improving the printing success rate.

[0028] The warpage online detection method proposed in the specific implementation process of the present invention has extended the design of the part structure, and unified the cross feature structure (i.e., the cross-shaped column 100) that is easy to form and convenient for online detection as the structural feature object for warpage deformation analysis and calculation, and combined with the technical idea of ​​deriving the overall warpage deformation of the structure from the boundary warpage deformation, the warpage deformation analysis algorithm is greatly simplified, and the compatibility of the online detection method with various complex structures is fully guaranteed.

[0029] The online warping detection method proposed in the specific implementation process of the present invention utilizes a 3D printing system with an online image detection function, which can collect image data of the printed structure during the part printing process, and at the same time adopts a warping deformation analysis algorithm for the Z-direction (the direction perpendicular to the plane of the printing base during the 3D printing process) characteristics to perform real-time quantitative analysis of its warping deformation state, and further analyze the degree of deterioration of the warping deformation over a period of time by comparing with the previous warping deformation state, thereby realizing online warping detection of large-scale high-performance polymer and composite material 3D printing.

[0030] Figure 1 A flow chart of an online warpage detection method based on 3D printing according to an embodiment of the present disclosure is shown. Figure 2 A schematic diagram showing a 3D printing state according to an embodiment of the present disclosure is shown.

[0031] like Figure 1 and Figure 2 As shown, in some embodiments, the warpage online detection method comprises at least the following steps:

[0032] S100, setting an expansion model around the component model to be printed to form a printing model.

[0033] S200, performing multi-layer 3D printing according to the printing model, and obtaining the height of the extended model of each printing layer to obtain actual height data.

[0034] S300: Calculate a height difference based on the actual height data and the corresponding standard height data to obtain warpage data.

[0035] S400: Control the 3D printer to continue or stop 3D printing based on the warping data.

[0036] In some embodiments, the step S400 may include:

[0037] S410, controlling the 3D printer to stop 3D printing based on the warping data.

[0038] S420: Control the 3D printer to continue 3D printing based on the warping data.

[0039] In some embodiments, step S300 may include:

[0040] S310, calculating height differences between the actual height data of the first expansion board 110, the actual height data of the second expansion board 120, and the actual height data of the third expansion board 130 and the corresponding standard height data, and then performing quantitative analysis on the height differences to obtain warping data;

[0041] Figure 3A schematic diagram of a discrete distribution coordinate system according to an embodiment of the present disclosure is shown.

[0042] Figure 4 A schematic diagram of a warpage distribution curve according to an embodiment of the present disclosure is shown.

[0043] Figure 5 A schematic diagram of a warping deformation distribution surface according to an embodiment of the present disclosure is shown.

[0044] like Figure 3 , Figure 4 and Figure 5 As shown, in some embodiments, step S310 may include:

[0045] S311 , respectively extracting actual height data of the first expansion board 110 , the second expansion board 120 , and the third expansion board 130 by using a feature recognition algorithm.

[0046] S312 , respectively comparing the actual height data of the first expansion board 110 , the second expansion board 120 , and the third expansion board 130 with the corresponding standard height data to obtain the height difference.

[0047] S313: Establish a discrete distribution coordinate system of the height difference based on the height difference.

[0048] Among them, in the step S313, the height difference is taken as the Z axis, the horizontal axis of the plane where the printing base surface is located is taken as the X axis, and the vertical axis of the plane where the printing base surface is located is taken as the Y axis to establish a discrete distribution coordinate system of the height difference. It should be noted that in a preferred embodiment, in the 3D printing process, the shape surrounded by the second expansion plate 120 and the third expansion plate 130 of all the cross-shaped columns 100 is a polygonal prism frame. The expansion model and the model of the component to be printed are connected together by a filling part 300. For the convenience of calculation, the values ​​of the X axis, Y axis and Z axis are all positive direction values ​​of point 0, that is, they are all positive numbers.

[0049] S314, performing fitting operation on the discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface.

[0050] S315, determining the warping data using the warping deformation distribution surface;

[0051] The actual height data of the first expansion board 110 extracted in step S311 is the actual height data of the free end of the first expansion board 110 .

[0052] The actual height data of the second expansion board 120 extracted in step S311 is the actual height data of the free end of the second expansion board 120 .

[0053] The actual height data of the third expansion board 130 extracted in step S311 is the actual height data of the free end of the third expansion board 130 .

[0054] In some embodiments, the step S314 may include:

[0055] S3141. In the discrete distribution coordinate system, perform interpolation fitting operation on discrete points corresponding to the height difference between the second expansion board 120 and the third expansion board 130 to obtain a warping deformation distribution curve.

[0056] S3142 . Based on the discrete points of the height difference of the first expansion board 110 and the warping deformation distribution curve, obtain a warping deformation distribution surface by fitting.

[0057] Wherein, in the step S3141, a one-dimensional interpolation method is used to perform fitting operation on the discrete points of the height difference to obtain a warping deformation distribution curve.

[0058] Among them, in the step S3142, a two-dimensional interpolation method is used to fit the discrete points of the height difference of the first expansion board 110 and the warping deformation distribution curve to obtain a warping deformation distribution surface. In this step, with the center of the minimum circumscribed circle of the pattern enclosed by the cross-shaped cylinder 100 on the plane where the printing base surface is located as the vertex, a surface passing through the warping deformation distribution curve and the discrete points of the height difference of the first expansion board 110 is fitted in the extension direction of the Z axis, that is, the warping deformation distribution surface.

[0059] In some embodiments, step S315 may include:

[0060] S3151, calculating the maximum value of the height difference between the actual height data of the i-th layer and the standard height data of the i-th layer, and obtaining the deformation data of the i-th layer;

[0061] Wherein, i is a natural number greater than or equal to 1.

[0062] If the deformation data of the i-th layer is greater than or equal to the first threshold, step S410 is executed.

[0063] It should be noted that the first threshold is the critical top-layer surface unevenness data. If the first threshold is exceeded, it is considered that the warping deformation makes it impossible to deposit and form normally above the printed structure. Printing is immediately paused, and the current warping deformation state is fed back, waiting for the top-layer surface to be repaired and leveled.

[0064] If the deformation data of the i-th layer is less than the first threshold, steps S3152 and S3153 are executed.

[0065] S3152. Preset a data collection cycle time based on the warping deformation distribution surface; calculate the height difference between the actual height data printed at the initial moment of the nth cycle and the standard height data at the initial moment of the nth cycle.

[0066] S3153, calculating the height difference between the actual height data printed at the end of the nth cycle and the standard height data printed at the end of the nth cycle.

[0067] S3154. Calculate the height difference between the initial moment of the nth period and the end moment of the nth period at the same horizontal and vertical coordinate positions in the discrete distribution coordinate system, take the maximum difference, and obtain the deformation increment of the nth period. If the deformation increment of the nth period is greater than or equal to the second threshold, execute step S410. If the deformation increment of the nth period is less than the second threshold, execute step S3155.

[0068] It should be noted that the second threshold is the critical maximum deformation increment of a single cycle. If it is greater than or equal to the second threshold, it is considered that the warping deformation state has deteriorated sharply or there is a layer splitting and detachment phenomenon, and the printing is immediately suspended, and the warping deformation increment is fed back, waiting for the printed structure to be repaired or reinforced;

[0069] S3155. Based on the warping deformation distribution surface, calculate the sum of the height differences at the same horizontal and vertical coordinate positions in each period from the mth period to the nth period in a discrete distribution coordinate system, take the minimum cumulative value, and obtain the cumulative deformation increment.

[0070] If the accumulated deformation increment is less than the third threshold, step S420 is executed.

[0071] If the accumulated deformation increment is greater than or equal to the third threshold, step S410 is executed.

[0072] It should be noted that the third threshold is the critical minimum deformation increment of several cycles. When the third threshold is exceeded, it is considered that the warping deformation causes a drastic deterioration in the adhesion between the bottom layer of the printed structure and the printing base surface, and the printing is immediately paused, and the warping deformation increment is fed back, waiting for the bonding strengthening of the bottom of the printed structure.

[0073] In some embodiments, after step S3151, step S3152, step S3153, step S3154, and step S3155 are executed, step S3152, step S3153, step S3154, and step S3155 are repeated for several rounds.

[0074] In some embodiments, after repeating step S3152, step S3153, step S3154, and step S3155, step S3151 is repeated.

[0075] Figure 6A schematic diagram of a cross-shaped column according to an embodiment of the present disclosure is shown.

[0076] like Figure 6 As shown, in some embodiments, the extended model is a plurality of cross-shaped cylinder 100 models, and the plurality of cross-shaped cylinder 100 models surround the to-be-printed component 200 model, and the cross-shaped cylinder 100 has a cross-shaped cross section along a plane parallel to the printing base surface.

[0077] It should be noted that the model of the component 200 to be printed is a model of the component 200 to be printed, that is, a model of the component 200 to be printed formed in a computer before 3D printing. The model of the cross-shaped cylinder 100 is a model of the cross-shaped cylinder 100, that is, a model of the cross-shaped cylinder 100 formed in a computer before 3D printing. The model of the filling part 300 is a model of the filling part 300, that is, a model of the filling part 300 formed in a computer before 3D printing. Since the warping deformation is mainly reflected in the top-level boundary of the structure, in order to reduce the difficulty of image acquisition and analysis, the top-level boundary is used as the direct detection object, and the technical idea of ​​deriving the overall warping deformation of the structure based on the boundary warping deformation is adopted.

[0078] Furthermore, in order to simplify the warpage deformation analysis algorithm and ensure the compatibility of the online detection method with various complex structures, the warpage online detection method proposed in the specific implementation process of the present invention extends the design of the parts, and arranges an outer enclosure shell with a cross feature structure on the outside of the parts. The two are connected by a filling part, and the cross feature structure (i.e., the cross-shaped column 100) is uniformly used as the structural object for warpage deformation analysis. The cross feature structure is easy to model, easy to form, easy to identify and extract features, and the extracted features are easy to calculate and analyze.

[0079] like Figure 2 As shown, in some embodiments, the extended model is a plurality of cross-shaped cylinders, and the plurality of cross-shaped cylinders surround the model of the component 200 to be printed, and the cross-section of the cross-shaped cylinder along the plane parallel to the printing base surface is cross-shaped.

[0080] In some embodiments, the expansion model is set around the model of the component 200 to be printed to form a printing model, which includes: setting a filling part 300 model between the model of the component 200 to be printed and the expansion model to obtain the printing model, and the filling part 300 model is used to connect the model of the component 200 to be printed and the expansion model into a whole.

[0081] In some embodiments, the filling portion 300 model is one or more of a linear structure, a grid structure, a solid structure, and the like.

[0082] In some embodiments, the filling portion 300 model is a straight line structure, and the filling portion 300 model is connected to the fourth expansion board 140 .

[0083] In some embodiments, the filling portion 300 model is an extension of the free end of the fourth expansion plate 140 of the cross-shaped column 100 , and the free end of the fourth expansion plate 140 extends to contact with the model of the component 200 to be printed.

[0084] In some embodiments, obtaining the height of the extended model of each printed layer includes: obtaining an image of the cross-shaped column 100 during 3D printing through an image acquisition device, and extracting the actual heights of each position of the cross-shaped column 100 in the image (i.e., the first expansion plate 110, the second expansion plate 120, and the third expansion plate 130) through a feature recognition algorithm.

[0085] In practical applications, before 3D printing, a model of the part 200 to be printed is first designed. While designing the model of the part 200 to be printed, the present disclosure sets an expansion model around the model of the part 200 to be printed to form a printing model. Then the printing model is data processed and a Gcode file is generated. The Gcode file is imported into the 3D printing system to start 3D printing. During the 3D printing process, the 3D printer prints layer by layer.

[0086] In some embodiments, an image acquisition device is used to obtain the actual height of the extended model of each printing layer.

[0087] It should be noted that the standard height data is the height data of the model of the component 200 to be printed, including the height data of each layer.

[0088] In some embodiments, the cross-shaped column 100 is divided by a cross position, and the cross-shaped column 100 may include: a first expansion plate 110, and the first expansion plate 110 is a plate away from one side of the model of the component 200 to be printed.

[0089] In some embodiments, the cross-shaped column 100 may include: a second expansion plate 120 , where the second expansion plate 120 is a plate perpendicular to the first expansion plate 110 .

[0090] In some embodiments, the cross-shaped column 100 may include: a third expansion plate 130 , wherein the third expansion plate 130 is a plate that is perpendicular to the first expansion plate 110 and symmetrical with the second expansion plate 120 along the intersection position.

[0091] In some embodiments, the cross-shaped column 100 may include: a fourth expansion plate 140, wherein the fourth expansion plate 140 is a plate close to one side of the model of the component 200 to be printed, and the fourth expansion plate 140 is used to connect the model of the component 200 to be printed.

[0092] It should be noted that the cross-shaped column 100 can be regarded as two cross-arranged plates, and the straight line where the two plates intersect is regarded as the intersection position, and the intersection position is perpendicular to the printing base surface. Among them, one plate is the second expansion plate 120 and the third expansion plate 130, and the plate is divided into the second expansion plate 120 and the third expansion plate 130 with the intersection position as the boundary; the other plate is the first expansion plate 110 and the fourth expansion plate 140, and the plate is divided into the first expansion plate 110 and the fourth expansion plate 140 with the intersection position as the boundary.

[0093] In some embodiments, the calculation of the height difference based on the actual height data and the corresponding standard height data to obtain the warping data may include: calculating the height difference between the actual height data of the first expansion board 110, the actual height data of the second expansion board 120, and the actual height data of the third expansion board 130 and the corresponding standard height data, respectively, and then quantifying and analyzing the height difference to obtain the warping data. It should be noted that the height difference is calculated between the actual height data of the first expansion board 110 and the standard height data corresponding to the first expansion board 110, the height difference is calculated between the actual height data of the second expansion board 120 and the standard height data corresponding to the second expansion board 120, and the height difference is calculated between the actual height data of the third expansion board 130 and the standard height data corresponding to the third expansion board 130.

[0094] In some embodiments, the actual height data of the first expansion board 110, the actual height data of the second expansion board 120, and the actual height data of the third expansion board 130 are respectively calculated with the corresponding standard height data, and the height difference is then quantified and analyzed to obtain warping data, including: using a feature recognition algorithm to respectively extract the actual height data of the first expansion board 110, the second expansion board 120, and the third expansion board 130; comparing the actual height data with the corresponding standard height data to obtain the height difference; establishing a discrete distribution coordinate system of the height difference based on the height difference; performing fitting operation on discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface; and determining the warping data using the warping deformation distribution surface.

[0095] In some embodiments, performing a fitting operation on the discrete distribution coordinate system to obtain a warping deformation distribution surface includes: performing an interpolation fitting operation on the discrete points corresponding to the height difference between the second expansion board and the third expansion board in the discrete distribution coordinate system to obtain a warping deformation distribution curve; and fitting the warping deformation distribution surface based on the discrete points of the height difference of the first expansion board and the warping deformation distribution curve.

[0096] In the discrete distribution coordinate system, discrete points of the height difference between the second expansion board 120 and the third expansion board 130 are selected to construct a two-dimensional coordinate system for distribution curve fitting operation, wherein the ordinate axis is the same as the vertical axis of the discrete distribution coordinate system, which is the height difference, and the abscissa axis is set to T(x, y), wherein x is the plane X-axis coordinate value during actual printing, and y is the plane Y-axis coordinate value during actual printing.

[0097] According to the arrangement of each of the second expansion board 120 and the third expansion board 130 on the outer circle of the model of the to-be-printed component 200, starting from any expansion board, in a fixed clock direction, the fixed clock direction is one of the clockwise direction and the counterclockwise direction, the adjacent expansion boards are selected in sequence, and the discrete points of the height difference of the adjacent expansion boards are arranged along the fixed coordinate axis direction on the horizontal coordinate T axis of the two-dimensional coordinate system, and the fixed coordinate axis direction is one of the positive direction and the negative direction. The distance between the discrete points of the height difference of the two adjacent expansion boards L_1 and L_2 on the T axis is the XY plane distance during actual printing, that is, √(〖(x_1-x_2)〗^2+〖(y_1-y_2)〗^2), where x1 and y1 are the plane X-axis and Y-axis coordinates of the expansion board L_1 during actual printing, and x_2 and y_2 are the plane X-axis and Y-axis coordinates of the expansion board L_2 during actual printing.

[0098] In the two-dimensional coordinate system, a one-dimensional interpolation method is used to perform fitting operation on the discrete points of the height difference between each of the second expansion board 120 and the third expansion board 130 to generate a distribution curve of the height difference on the T coordinate axis. Optionally, a B-spline interpolation fitting method is used.

[0099] The distribution curve of the height difference on the T coordinate axis is converted into the warping deformation distribution curve located within the boundary in the discrete distribution coordinate system. Optionally, the method is: using the ordinate value in the two-dimensional coordinate system as the vertical coordinate value in the discrete distribution coordinate system, and restoring the horizontal coordinate value T(x, y) in the two-dimensional coordinate system in the form of corresponding x values ​​and y values ​​to the plane coordinate point on the actual printing distance X of the horizontal coordinate axis and the actual printing distance Y of the vertical coordinate axis in the discrete distribution coordinate system, so as to form the warping deformation distribution curve in the discrete distribution coordinate system.

[0100] It should be noted that the Z-direction warping deformation (i.e., the height difference) reflected on the top surface of the extended model is fitted by a two-dimensional interpolation method to generate a warping deformation distribution surface of the entire printed model. The warping deformation distribution surface passes through the distribution curve and each discrete point of the height difference to obtain the overall real-time warping deformation state. Optionally, Parabola2D nonlinear fitting is used, z = a*x2+b*y2+c*x+d*y+z0. a, b, c, d, z0 are constants, x and y are the values ​​of the X-axis coordinates and the Y-axis coordinates at the same discrete point, and z is the height difference at the (x, y) coordinates.

[0101] In some embodiments, determining the warping data using the warping deformation distribution surface includes: calculating the maximum value of the height difference between the actual height data of the i-th layer and the standard height data of the i-th layer, and obtaining the deformation data of the i-th layer; wherein i is a natural number greater than or equal to 1, and the warping data includes the deformation data.

[0102] In some embodiments, controlling the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation data of the i-th layer is greater than or equal to a first threshold, stopping 3D printing.

[0103] In some embodiments, if the deformation data of the i-th layer is less than a first threshold, determining the warping data using the warping deformation distribution surface also includes: based on the warping deformation distribution surface, presetting a data acquisition cycle time; calculating the height difference between the actual height data printed at the initial moment of the n-th cycle and the standard height data at the initial moment of the n-th cycle; calculating the height difference between the actual height data printed at the end moment of the n-th cycle and the standard height data at the end moment of the n-th cycle; calculating the difference in height between the initial moment of the n-th cycle and the end moment of the n-th cycle at the same horizontal and vertical coordinate positions in a discrete distribution coordinate system, taking the maximum difference, and obtaining the deformation increment of the n-th cycle; wherein n is a natural number greater than or equal to 1; and the warping data includes the deformation increment.

[0104] In some embodiments, the data collection cycle time is manually defined and can be preset according to factors such as the size and shape of the component to be printed.

[0105] In some embodiments, the time for printing a layer is divided into several data collection cycle times.

[0106] In some embodiments, controlling the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation increment of the nth cycle is greater than or equal to a second threshold, stopping 3D printing.

[0107] In some embodiments, if the deformation increment of the nth period is less than the second threshold, determining the warping data using the warping deformation distribution surface also includes: based on the warping deformation distribution surface, calculating the sum of the height differences at the same horizontal and vertical coordinate positions in each period from the mth period to the nth period in a discrete distribution coordinate system, taking the minimum cumulative value, and obtaining the cumulative deformation increment; if the cumulative deformation increment is less than a third threshold, continuing 3D printing; if the cumulative deformation increment is greater than or equal to the third threshold, stopping 3D printing; wherein m is a natural number less than n; and the warping data includes the cumulative deformation increment.

[0108] According to the specific implementation mode proposed in the specific implementation process of the present invention, on the other hand, the present disclosure provides an online warping detection system based on 3D printing, which may include: a modeling unit, the modeling unit is used to set an extended model around the model of the component 200 to be printed to form a printing model; an acquisition unit 400, the acquisition unit 400 is used to perform multi-layer 3D printing according to the printing model, and obtain the height of the extended model of each printing layer to obtain actual height data; a processing unit, the processing unit is used to calculate the height difference based on the actual height data and the corresponding standard height data to obtain warping data; a control unit, the control unit is used to control the 3D printer to continue or stop 3D printing based on the warping data.

[0109] The warping online detection system proposed in the specific implementation process of the present invention makes real-time judgment on the warping deformation state of the printed structure based on the collected image data through the warping deformation analysis algorithm, and compares and analyzes the warping deformation increment after a period of time. For severe and drastically deteriorating warping deformation, the printing process is promptly suspended and corresponding feedback is given.

[0110] The processing unit is also used to calculate the height difference between the actual height data of the first expansion board 110, the actual height data of the second expansion board 120 and the actual height data of the third expansion board 130 and the corresponding standard height data, and then quantify the height difference to obtain warping data.

[0111] The processing unit is further configured to respectively extract actual height data of the first expansion board 110 , the second expansion board 120 , and the third expansion board 130 by using a feature recognition algorithm.

[0112] The processing unit is further used to compare the actual height data with the corresponding standard height data to obtain the height difference.

[0113] The processing unit is further configured to establish a discrete distribution coordinate system of the height difference based on the height difference.

[0114] The processing unit is further used to perform a fitting operation on the discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface.

[0115] The processing unit is further configured to determine the warping data using the warping deformation distribution surface.

[0116] The processing unit is further configured to perform interpolation fitting operations on discrete points corresponding to the height difference between the second expansion board 120 and the third expansion board 130 in the discrete distribution coordinate system to obtain a warping deformation distribution curve.

[0117] The processing unit is further configured to obtain a warping deformation distribution surface by fitting based on the discrete points of the height difference of the first expansion board 110 and the warping deformation distribution curve.

[0118] The processing unit is also used to calculate the maximum value of the height difference between the actual height data of the i-th layer and the standard height data of the i-th layer to obtain the deformation data of the i-th layer; wherein i is a natural number greater than or equal to 1; and the warping data includes the deformation data.

[0119] The processing unit is also used to compare the deformation data of the i-th layer with a first threshold; if the deformation data of the i-th layer is greater than or equal to the first threshold, a stop instruction is sent to the control unit, and the control unit controls the 3D printer to stop 3D printing according to the stop instruction.

[0120] If the deformation data of the i-th layer is less than a first threshold value, the processing unit is also used to preset a data acquisition cycle time based on the warping deformation distribution surface; calculate the height difference between the actual height data printed at the initial moment of the n-th cycle and the standard height data at the initial moment of the n-th cycle; calculate the height difference between the actual height data printed at the end moment of the n-th cycle and the standard height data at the end moment of the n-th cycle; calculate the difference in height between the initial moment of the n-th cycle and the end moment of the n-th cycle at the same horizontal and vertical coordinate positions in a discrete distribution coordinate system, take the maximum difference, and obtain the deformation increment of the n-th cycle; wherein n is a natural number greater than or equal to 1; and the warping data includes the deformation increment.

[0121] The processing unit is also used to compare the deformation increment of the nth cycle with a second threshold; if the deformation increment of the nth cycle is greater than or equal to the first threshold, a stop instruction is sent to the control unit, and the control unit controls the 3D printer to stop 3D printing according to the stop instruction.

[0122] If the deformation increment of the nth period is less than the second threshold, the processing unit is also used to calculate the sum of the height differences at the same horizontal and vertical coordinate positions in each period from the mth period to the nth period in a discrete distribution coordinate system based on the warping deformation distribution surface, take the minimum cumulative value, and obtain the cumulative deformation increment; wherein m is a natural number less than n; and the warping data includes the cumulative deformation increment.

[0123] The processing unit is also used to compare the accumulated deformation increment with a third threshold; if the accumulated deformation increment is greater than or equal to the third threshold, send a stop instruction to the control unit, and the control unit controls the 3D printer to stop 3D printing according to the stop instruction.

[0124] The warping data may include one or more of the deformation data, the deformation increment and the accumulated deformation increment.

[0125] An embodiment of the present disclosure provides a 3D printer, which includes the online warping detection system described in any one of the above technical solutions and can execute the online warping detection method described in any one of the above technical solutions.

[0126] An embodiment of the present disclosure provides a 3D printing system, which includes the 3D printer described in any one of the above technical solutions.

[0127] A fused deposition modeling 3D printing system with online image detection capability is used to prepare large-scale complex structural parts. In addition to the mechanical components and control system required by the fused deposition modeling 3D printer, the 3D printing system also includes two image acquisition devices with data transmission channels, an image data storage device, and an image data processing system. The printing material is a PEEK-based composite material.

[0128] In another embodiment of the present disclosure, an electronic device is provided, which is used for an audio and video processing method based on display position, and the electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the one processor, and the instructions are executed by the at least one processor so that the at least one processor can: set an extended model around the model of the component to be printed to form a printing model; perform multi-layer 3D printing according to the printing model, and obtain the height of the extended model of each printing layer to obtain actual height data; calculate the height difference based on the actual height data and the corresponding standard height data to obtain warping data; and control the 3D printer to continue or stop 3D printing based on the warping data.

[0129] In another embodiment of the present disclosure, a non-volatile computer storage medium is provided, wherein the computer storage medium stores computer executable instructions, and the computer executable instructions can execute the online warpage detection method based on 3D printing in any of the above method embodiments.

[0130] The present disclosure aims to protect an online warpage detection method and system based on 3D printing. The online warpage detection method may include: setting an extended model around the model of the part to be printed to form a printed model; performing multi-layer 3D printing according to the printed model, and obtaining the height of the extended model of each printed layer to obtain actual height data; calculating the height difference based on the actual height data and the corresponding standard height data to obtain warpage data; and controlling the 3D printer to continue or stop 3D printing based on the warpage data. The online warpage detection method proposed in the specific implementation process of the present invention is an online detection method for warpage deformation of 3D printed large-size high-performance polymer and composite parts. The online warpage detection method proposed in the specific implementation process of the present invention has low cost when executed and a wide range of parts applications. It can avoid the direct failure of part printing after severe warpage deformation during printing, which is conducive to improving the printing success rate and improving the forming quality and precision of the part body.

[0131] The units involved in the embodiments described in the present disclosure may be implemented by software or hardware. The name of a unit does not limit the unit itself in some cases. For example, a modeling unit may also be described as a "unit for setting an extended model around a part model to be printed to form a printed model."

[0132] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for online detection of warpage based on 3D printing, characterized in that: An extended model is set around the model of the component to be printed to form a printing model; multi-layer 3D printing is performed according to the printing model, and the height of the extended model of each printing layer is obtained to obtain actual height data; the height difference is calculated based on the actual height data and the corresponding standard height data to obtain warping data; based on the warping data, the 3D printer is controlled to continue or stop 3D printing.

2. The method for online warpage detection based on 3D printing according to claim 1, characterized in that: The extended model is a model of multiple cross-shaped cylinders; the multiple cross-shaped cylinder models surround the model of the component to be printed; and the cross-section of the cross-shaped cylinder along the plane parallel to the printing base surface is cross-shaped.

3. The method for online detection of warpage based on 3D printing according to claim 2, characterized in that: The cross-shaped column is divided by an intersection position and includes: a first expansion plate, which is a plate away from one side of the component model to be printed; a second expansion plate, which is a plate perpendicular to the first expansion plate; a third expansion plate, which is a plate perpendicular to the first expansion plate and symmetrical with the second expansion plate along the intersection position; a fourth expansion plate, which is a plate close to one side of the component model to be printed, and is used to connect the component model to be printed; the actual height data of the first expansion plate, the actual height data of the second expansion plate, and the actual height data of the third expansion plate are respectively calculated with the corresponding standard height data for height difference, and then the height difference is quantitatively analyzed to obtain warping data.

4. The method for online detection of warpage based on 3D printing according to claim 3, characterized in that: The actual height data of the first expansion board, the actual height data of the second expansion board, and the actual height data of the third expansion board are respectively calculated with the corresponding standard height data, and the height difference is then quantified and analyzed to obtain the warping data, including: using a feature recognition algorithm to respectively extract the actual height data of the first expansion board, the second expansion board, and the third expansion board; comparing the actual height data with the corresponding standard height data to obtain the height difference; establishing a discrete distribution coordinate system of the height difference based on the height difference; performing fitting operation on discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface; and determining the warping data using the warping deformation distribution surface.

5. The method for online warpage detection based on 3D printing according to claim 4, characterized in that: Performing a fitting operation on the discrete points of the height difference in the discrete distribution coordinate system to obtain a warping deformation distribution surface includes: performing an interpolation fitting operation on the discrete points corresponding to the height difference between the second expansion board and the third expansion board in the discrete distribution coordinate system to obtain a warping deformation distribution curve; and fitting the warping deformation distribution surface based on the discrete points of the height difference of the first expansion board and the warping deformation distribution curve.

6. The method for online detection of warpage based on 3D printing according to claim 5, characterized in that: Determining the warping data using the warping deformation distribution surface includes: calculating the maximum value of the height difference between the actual height data of the i-th layer and the standard height data of the i-th layer to obtain the deformation data of the i-th layer; wherein i is a natural number greater than or equal to 1; and the warping data includes the deformation data.

7. The method for online detection of warpage based on 3D printing according to claim 6, characterized in that: The controlling of the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation data of the i-th layer is greater than or equal to a first threshold, stopping 3D printing; if the deformation data of the i-th layer is less than the first threshold, determining the warping data using the warping deformation distribution surface also includes: based on the warping deformation distribution surface, presetting a data acquisition cycle time; calculating the height difference between the actual height data printed at the initial moment of the n-th cycle and the standard height data at the initial moment of the n-th cycle; calculating the height difference between the actual height data printed at the end moment of the n-th cycle and the standard height data at the end moment of the n-th cycle; calculating the difference in height between the same horizontal and vertical coordinate positions at the initial moment of the n-th cycle and the end moment of the n-th cycle in a discrete distribution coordinate system, taking the maximum difference, and obtaining the deformation increment of the n-th cycle; wherein n is a natural number greater than or equal to 1; the warping data includes the deformation increment.

8. The method for online warpage detection based on 3D printing according to claim 7, characterized in that ,, the controlling the 3D printer to continue or stop 3D printing based on the warping data includes: if the deformation increment of the nth cycle is greater than or equal to a second threshold, stopping 3D printing.

9. The method for online detection of warpage based on 3D printing according to claim 7, characterized in that: If the deformation increment of the i-th layer is less than the second threshold, determining the warping data using the warping deformation distribution surface also includes: based on the warping deformation distribution surface, calculating the sum of the height differences at the same horizontal and vertical coordinate positions in each period from the m-th period to the n-th period in the discrete distribution coordinate system, taking the minimum cumulative value, and obtaining the cumulative deformation increment; if the cumulative deformation increment is less than the third threshold, continuing 3D printing; if the cumulative deformation increment is greater than or equal to the third threshold, stopping 3D printing; wherein m is a natural number less than n; and the warping data includes the cumulative deformation increment.

10. A 3D printing-based warpage online detection system, used to implement the detection method according to any one of claims 1 to 9, characterized in that: include: A modeling unit, the modeling unit is used to set an extended model around the model of the part to be printed to form a printed model; an acquisition unit, the acquisition unit is used to obtain the height of the extended model of each printing layer during multi-layer 3D printing to obtain actual height data; a processing unit, the processing unit is used to calculate the height difference based on the actual height data and the corresponding standard height data to obtain warping data; a control unit, the control unit is used to control the 3D printer to continue or stop 3D printing based on the warping data.

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