A method, apparatus, and equipment for dimensional compensation and scaling of additive manufacturing part models.

Abstract

This invention relates to the field of industrial information technology and discloses a method, apparatus, and device for dimensional compensation and scaling of additive manufacturing part models. The invention establishes a reference axis, calculates the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and scaled within the additive manufacturing part model, and the reference axis. It then combines the initial coordinates of each triangle vertex with the dimensional compensation function along the coordinate axis and the coordinates of the scaling reference center to determine the final dimensionally compensated and scaled target additive manufacturing part model. This ensures that the planes formed by the triangles originally perpendicular to the coordinate axis to be compensated maintain consistent coordinate values ​​along that axis after compensation, thus improving both the dimensional accuracy and appearance of the additive manufacturing part model.

Description

Technical Field

[0001] This invention relates to the field of industrial information technology, and specifically to a method, apparatus, and equipment for size compensation and scaling of additive manufacturing part models. Background Technology

[0002] In selective laser sintering (SLS), the difference in shrinkage of the workpiece at different positions in the forming cylinder will lead to accuracy errors. To address this issue, before processing, the forming data processing software uses a dimensional compensation function to scale the additive manufacturing part model drawing of the workpiece. Specifically, it calculates the scaling factor along a single coordinate axis based on the coordinates of the vertices of the triangular faces in the forming space coordinate system and the dimensional compensation function, and recalculates the coordinates of the triangular face vertices based on a fixed scaling center. The resulting additive manufacturing part model file is then used for processing to compensate for the dimensional errors caused by shrinkage differences. Since the workpiece at different positions in the forming cylinder experiences pressure... The values ​​and heating temperatures vary, and the time spent in these environments also differs. The dimensional compensation function used is nonlinear. Although it can effectively improve the dimensional accuracy of the workpiece, the method of calculating the compensation coefficient of the coordinate direction to be compensated separately based on the coordinate position of each point in the additive manufacturing part model in the forming space, and obtaining the coordinates of the compensated point as the coordinate points of the additive manufacturing part model during actual forming, will cause the plane composed of the triangular faces that were originally perpendicular to the coordinate axis to be compensated to no longer be on the plane perpendicular to the coordinate axis to be compensated due to the different compensation coefficients. The actual processed plane will have obvious step patterns, affecting the appearance quality of the additive manufacturing part. Summary of the Invention

[0003] In view of this, the present invention provides a method, apparatus and equipment for size compensation and scaling of additive manufacturing part models, to solve the problem that the method of calculating the compensation coefficient of the coordinate direction to be compensated based on the coordinate position of each point in the additive manufacturing part model in the forming space, and obtaining the compensated point coordinates as the coordinate points of the additive manufacturing part model during actual forming, will no longer be on the plane perpendicular to the coordinate axis to be compensated due to the nonlinear compensation function. This will result in obvious step patterns appearing on the actual processed plane, affecting the appearance quality of the workpiece.

[0004] In a first aspect, the present invention provides a method for dimensional compensation and scaling of an additive manufacturing part model, the method comprising:

[0005] Obtain the initial coordinate values ​​of each triangular face vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the dimensional compensation function and scaling reference center coordinate values ​​in the direction of the coordinate axis to be compensated. The forming space coordinate system represents a Cartesian coordinate system established in the forming space defined by the forming chamber hardware used to form the workpiece in the forming equipment, with the origin of the coordinate system located at any point in the forming space. Obtain the monotonically increasing objective function in the direction of the coordinate axis to be compensated, which can be either a continuous function or a piecewise function. Determine the reference axis of the additive manufacturing part model to be compensated and scaled in the direction of the coordinate axis to be compensated based on the objective function. Calculate the coordinate values ​​of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the additive manufacturing part model to be compensated and scaled. Based on the dimensional compensation function, the scaling reference center coordinate values, each intersection point coordinate value, and each initial coordinate value, determine the target additive manufacturing part model after dimensional compensation and scaling.

[0006] The additive manufacturing part model size compensation and scaling method provided by this invention sets a corresponding reference axis in the direction of the coordinate axis to be compensated and scaled for the additive manufacturing part model to be compensated and scaled by a monotonically increasing objective function in the direction of the coordinate axis to be compensated. Then, it calculates the coordinate values ​​of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and scaled within the additive manufacturing part model and the reference axis. By combining the initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled, the size compensation function in the direction of the coordinate axis to be compensated, and the coordinate values ​​of the scaling reference center, the final target additive manufacturing part model after size compensation and scaling can be determined. This ensures that the coordinate values ​​of the plane formed by the triangles originally perpendicular to the coordinate axis to be compensated remain consistent in the direction of the coordinate axis after compensation, thereby improving both the dimensional accuracy and appearance of the additive manufacturing part model to be compensated and scaled.

[0007] In one optional implementation, the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additively manufactured part to be compensated for all triangular facets are calculated, including:

[0008] Obtain the plane equation for each plane and the parametric equation for the reference axis; based on each plane equation and parametric equation, calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated for scaling.

[0009] The additive manufacturing part model size compensation and scaling method provided by this invention can calculate the coordinate values ​​of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis by combining the plane equation of each plane and the parametric equation of the reference axis, thus providing support for the subsequent size compensation and scaling of the model.

[0010] In one optional implementation, the target additive manufacturing part model after size compensation and scaling is determined based on the size compensation function, the scaling reference center coordinates, the coordinates of each intersection point, and each initial coordinate value, including:

[0011] Based on the coordinates of each intersection point and the size compensation function, the compensation scaling factor is determined; based on the compensation scaling factor, the coordinates of the scaling reference center, and each initial coordinate value, the target coordinates of each triangle vertex after size compensation scaling are determined; based on each target coordinate value, the target additive manufacturing part model after size compensation scaling is determined.

[0012] The additive manufacturing part model size compensation and scaling method provided by this invention can calculate the compensation scaling coefficient based on the size compensation function using the intersection point coordinates and the size compensation function. Furthermore, the compensation scaling coefficient is used as the compensation scaling coefficient of the additive manufacturing part model to be compensated and scaled, and the size compensation and scaling of the model is performed. This ensures that the coordinate values ​​of the plane formed by the triangular faces that were originally perpendicular to the coordinate axis to be compensated remain consistent in the direction of the coordinate axis after compensation. This improves both the dimensional accuracy and the appearance of the additive manufacturing part model to be compensated and scaled.

[0013] In one alternative implementation, the parametric equation of the objective function is expressed as:

[0014]

[0015] In the formula: x2, y2, z2 represent the coordinate values ​​of the reference axis determined by the parametric equation at parameter t; x2(t), y2(t), z2(t) represent the functional relationships between x2, y2, z2 and parameter t, respectively; a, b represent the range of values ​​of parameter t, which are determined by the objective function.

[0016] In one optional implementation, the target coordinate value of each triangle vertex after size compensation scaling is determined based on the compensation scaling factor, the scaling reference center coordinate value, and each initial coordinate value, including: determining it through the following relationship:

[0017]

[0018] In the formula: c′ represents the target coordinate value of the triangle vertex in the corresponding coordinate axis direction after size compensation scaling; c orisbaseThis represents the coordinate value of the scaling reference center along the corresponding coordinate axis; (x intersect ,y intersect ,z intersect () represents the coordinates of the intersection point; This represents the compensation scaling factor in the corresponding coordinate axis direction; c ori This represents the initial coordinate value in the corresponding coordinate axis direction.

[0019] In an alternative implementation, the method further includes processing the target additive manufacturing part model using selective laser sintering technology.

[0020] In a second aspect, the present invention provides a size compensation and scaling device for additive manufacturing part models, the device comprising:

[0021] The first acquisition module is used to acquire the initial coordinate values ​​of each triangular face vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the size compensation function and scaling reference center coordinate values ​​in the direction of the coordinate axis to be compensated. The forming space coordinate system represents a Cartesian coordinate system established in the forming space determined by the forming chamber hardware used to form the workpiece in the forming equipment, with the origin of the coordinate system located at any point in the forming space. The second acquisition module is used to acquire the monotonically increasing objective function in the direction of the coordinate axis to be compensated, which can be either a continuous function or a piecewise function. The first determination module is used to determine the reference axis of the additive manufacturing part model to be compensated and scaled in the direction of the coordinate axis to be compensated based on the objective function. The calculation module is used to calculate the coordinate values ​​of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis in the additive manufacturing part model to be compensated and scaled. The second determination module is used to determine the target additive manufacturing part model after size compensation and scaling based on the size compensation function, the scaling reference center coordinate values, the coordinate values ​​of each intersection point, and each initial coordinate value.

[0022] Thirdly, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to perform the additive manufacturing part model size compensation and scaling method of the first aspect or any corresponding embodiment described above.

[0023] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the additive manufacturing part model size compensation scaling method of the first aspect or any corresponding embodiment described above.

[0024] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the additive manufacturing part model size compensation and scaling method of the first aspect or any corresponding embodiment described above. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a single additive manufacturing part model to be formed according to an embodiment of the present invention;

[0027] Figure 2A This is a top view of additive manufacturing parts to be formed, which are located at different positions within the forming space according to an embodiment of the present invention.

[0028] Figure 2B This is a schematic diagram of an additive manufacturing part model before compensation based on the coordinates of individual points according to a nonlinear compensation function, according to an embodiment of the present invention.

[0029] Figure 2C This is a schematic diagram of an additive manufacturing part model after compensation based on the coordinates of individual points according to a nonlinear compensation function, according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic flowchart of a method for size compensation and scaling of an additive manufacturing part model according to an embodiment of the present invention;

[0031] Figure 4 This is a schematic flowchart of another additive manufacturing part model size compensation and scaling method according to an embodiment of the present invention;

[0032] Figure 5 This is a flowchart illustrating another additive manufacturing part model size compensation and scaling method according to an embodiment of the present invention;

[0033] Figure 6A This is a top view of 45 STLs that are compensated for scaling within the molding space according to an embodiment of the present invention;

[0034] Figure 6B This is a right view of 45 STLs with compensated scaling within the molding space according to an embodiment of the present invention;

[0035] Figure 7This is a schematic diagram of the intersection of the center line of the vertical horizontal plane of the bounding box of the molding space geometry determined by the molding chamber hardware according to an embodiment of the present invention and the lowest horizontal plane of the space of the molding chamber used for molding the workpiece.

[0036] Figure 8 This is a schematic diagram of the STL triangle face vertex, the plane perpendicular to the z-coordinate axis where the vertex is located, the center line of the STL minimum axis aligned bounding box in the z-coordinate axis direction, and the intersection point of the plane and the center line according to an embodiment of the present invention.

[0037] Figure 9 This is a structural block diagram of a size compensation and scaling device for an additive manufacturing part model according to an embodiment of the present invention;

[0038] Figure 10 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In selective laser sintering (SLS), powder material is precisely fed, spread, and heated before being precisely sintered by a laser according to the cross-sectional contour, layer by layer, to form a part. During this process, dimensional accuracy issues arise due to shrinkage differences within the workpiece position in the forming cylinder. Therefore, a nonlinear dimensional compensation algorithm is used to process the additive manufacturing part model before processing: based on the coordinates of the triangle vertices in the forming space, the scaling ratio in each coordinate axis direction is calculated, and the scaling center is fixed to reposition the vertices, generating a corrected additive manufacturing part model to compensate for shrinkage errors. A single additive manufacturing part model to be formed is shown below. Figure 1 As shown.

[0041] However, this method, which calculates compensation coefficients independently based on single-point coordinates and applies nonlinear compensation functions, causes the triangular faces originally perpendicular to the compensation axis to deviate from their original perpendicularity to the coordinate axis to be compensated due to varying compensation values. As a result, the surface of the processed additively manufactured parts exhibits significant step-like textures, negatively impacting the appearance quality of the additively manufactured parts.

[0042] For example, a method that independently calculates compensation coefficients based on the coordinate position of a single point and applies a nonlinear compensation function is used for... Figure 2AThe dimensional accuracy of the additive manufacturing parts to be formed, which are located at different positions within the forming space, after dimensional compensation is shown in Table 1 below:

[0043] Table 1. Dimensional accuracy of additively manufactured parts after compensation based on independent calculation of compensation coefficients using single-point coordinate positions and application of nonlinear compensation functions.

[0044]

[0045]

[0046] For example, such as Figure 2B and Figure 2C As shown, after compensation based on the coordinates of individual points using a nonlinear compensation function, the z-coordinate values ​​of the vertices of the triangular face originally perpendicular to the compensation axis are no longer at the same height. The resulting plane parallel to the xy-plane (perpendicular to the z-axis) will no longer be parallel to the xy-plane (no longer perpendicular to the z-axis). Therefore, by independently calculating the compensation coefficient based on the coordinates of a single point and applying a nonlinear compensation function, the triangular face originally perpendicular to the compensation axis deviates from its original perpendicularity due to the varying compensation values ​​of each vertex, resulting in a significant step-like texture on the surface of the machined workpiece.

[0047] According to an embodiment of the present invention, a method for size compensation scaling of an additive manufacturing part model is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0048] This embodiment provides a method for dimensional compensation and scaling of additive manufacturing part models, which can be used in electronic devices such as computers, mobile phones, and tablets. Figure 3 This is a flowchart of a method for dimensional compensation and scaling of an additive manufacturing part model according to an embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps:

[0049] Step S301: Obtain the initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the size compensation function and scaling reference center coordinate values ​​in the direction of the coordinate axis to be compensated.

[0050] Specifically, the forming space coordinate system refers to a Cartesian coordinate system established within the forming space defined by the forming chamber hardware used for forming the workpiece in the forming equipment, with the origin of the coordinate system located at any point within the forming space. Here, forming space refers to the space within the forming equipment chamber used for forming the workpiece in selective laser sintering (SLS) technology.

[0051] Preferably, the origin of the coordinate system is located on the center line of the vertical horizontal plane of the bounding box of the molding space geometry determined by the molding chamber hardware.

[0052] Optimal, the origin of the coordinate system is located at the intersection of the centerline of the vertical horizontal plane of the axis-aligned bounding box of the forming space geometry defined by the forming chamber hardware and the lowest horizontal plane of the space in the forming chamber used to form the workpiece.

[0053] Furthermore, the size compensation function can be obtained from a fixed scaling center point, and its output is a function of any form representing the scaling factor of a single point in the corresponding coordinate axis direction.

[0054] The fixed scaling center point represents the scaling reference point selected when obtaining the size compensation function, which can be any point in the forming space coordinate system.

[0055] Preferably, the fixed scaling center point is located on the center line of the vertical horizontal plane of the bounding box of the molding space geometry determined by the molding chamber hardware.

[0056] Optimal, the fixed scaling center point is located at the intersection of the center line of the vertical horizontal plane of the axis-aligned bounding box of the molding space geometry determined by the molding chamber hardware and the lowest horizontal plane of the space in the molding chamber used to mold the workpiece.

[0057] Specifically, the dimension compensation function in a single coordinate direction is expressed as the following relationship (1):

[0058]

[0059] In the formula: (x1, y1, z1) represents the original coordinate values ​​of any point in the additive manufacturing part model in the forming space coordinate system; The scaling factor represents the compensation scaling factor at any point in the additive manufacturing part model along the corresponding coordinate axis; f(x1,y1,z1) represents the functional relationship between (x1,y1,z1) and the compensation scaling factor.

[0060] Furthermore, the scaling reference center coordinates represent the coordinates of the scaling reference center in the forming space coordinate system. The scaling reference center can be any point in the forming space coordinate system.

[0061] Preferably, the distance between the scaling reference center and the fixed scaling center point is less than or equal to 100mm.

[0062] Ideally, the scaling reference center should coincide with the fixed scaling center point.

[0063] Step S302: Obtain the objective function that increases monotonically in the direction of the coordinate axis to be compensated.

[0064] Specifically, the objective function can be either a continuous function or a piecewise function.

[0065] Step S303: Determine the reference axis of the additive manufacturing part model to be compensated in the direction of the coordinate axis to be compensated based on the objective function.

[0066] Specifically, when the objective function is a continuous function that monotonically increases in the direction of the coordinate axis to be compensated, the reference axis can be a continuous straight line or a curve.

[0067] Furthermore, when the objective function is a piecewise function that monotonically increases along the coordinate axis to be compensated, the reference axis can be a piecewise straight line or curve.

[0068] Preferably, the reference axis is the center line of the bounding box of the additive manufacturing part model to be compensated for in the direction of the coordinate axis to be compensated.

[0069] Step S304: Calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated for all the vertices of the triangular faces.

[0070] Specifically, the intersection coordinates represent the coordinates of the intersection points of the plane perpendicular to the coordinate axis to be compensated and the corresponding reference axis within the model of the additively manufactured part to be compensated, where all the vertices of the triangular faces are located.

[0071] Step S305: Based on the size compensation function, the coordinate values ​​of the scaling reference center, the coordinate values ​​of each intersection point, and each initial coordinate value, determine the target additive manufacturing part model after size compensation and scaling.

[0072] Specifically, based on the obtained coordinate values ​​of multiple intersection points, the obtained size compensation function, the coordinate values ​​of the scaling reference center, and each initial coordinate value are combined to perform size compensation scaling on the additive manufacturing part model to be compensated and scaled, and obtain the target additive manufacturing part model after size compensation scaling. This improves the dimensional accuracy of the additive manufacturing part model to be compensated and scaled while also improving its appearance.

[0073] The dimension compensation and scaling method for additive manufacturing part models provided in this embodiment sets a corresponding reference axis for the additive manufacturing part model to be compensated and scaled in the direction of the coordinate axis to be compensated by a monotonically increasing objective function. Then, it calculates the coordinate values ​​of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis at the vertices of all triangular faces in the additive manufacturing part model. By combining the initial coordinate values ​​of each triangular face vertex of the additive manufacturing part model to be compensated and scaled, the dimension compensation function in the direction of the coordinate axis to be compensated, and the coordinate values ​​of the scaling reference center, the final dimension-compensated and scaled target additive manufacturing part model can be determined. This ensures that the coordinate values ​​of the plane formed by the triangular faces originally perpendicular to the coordinate axis to be compensated remain consistent in the direction of the coordinate axis after compensation, thereby improving both the dimensional accuracy and appearance of the additive manufacturing part model to be compensated and scaled.

[0074] This embodiment provides a method for dimensional compensation and scaling of additive manufacturing part models, which can be used in electronic devices such as computers, mobile phones, and tablets. Figure 4 This is a flowchart of a method for dimensional compensation and scaling of an additive manufacturing part model according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps:

[0075] Step S401: Obtain the initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the dimension compensation function and scaling reference center coordinate values ​​along the coordinate axes to be compensated. For details, please refer to [link to relevant documentation]. Figure 3 Step S301 of the illustrated embodiment will not be described again here.

[0076] Step S402: Obtain the objective function that increases monotonically along the coordinate axis to be compensated. For details, please refer to [link to relevant documentation]. Figure 3 Step S302 of the illustrated embodiment will not be described again here.

[0077] Step S403: Determine the reference axis of the additive manufacturing part model to be compensated in the direction of the coordinate axis to be compensated based on the objective function. For details, please refer to [link to relevant documentation]. Figure 3 Step S303 of the illustrated embodiment will not be described again here.

[0078] Step S404: Calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated for all the vertices of the triangular faces.

[0079] Specifically, step S404 includes:

[0080] Step S4041: Obtain the plane equation of each plane and the parametric equation of the objective function corresponding to the reference axis.

[0081] Specifically, the plane equation for each plane is shown in the following relation (2):

[0082] Ax + By + Cz + D = 0 (2)

[0083] In the formula: A, B, and C represent the three components of the normal vector of the plane perpendicular to the coordinate axis to be compensated, where the coordinates of a single point on each plane are located; x, y, and z represent the coordinate values ​​of a single point on each plane; D represents the distance between the plane and the origin. When calculating different coordinate axis directions to be compensated, the values ​​of A, B, C, and D are as shown in the following relationship (3):

[0084]

[0085] In the formula: x ori y ori , z ori This represents the initial coordinates of a single point to be calculated in the modeling space coordinate system.

[0086] Furthermore, the parametric equation of the objective function is shown in the following relation (4):

[0087]

[0088] In the formula: x2, y2, z2 represent the coordinate values ​​of the reference axis determined by the parametric equation at parameter t; x2(t), y2(t), z2(t) represent the functional relationships between x2, y2, z2 and the reference axis parameter t, respectively; a, b represent the range of values ​​of the reference axis parameter t, which are determined by the objective function.

[0089] Furthermore, when the objective function is a continuous function, a = -∞, b = +∞, and x2(t), y2(t), z2(t) have unique forms; when the objective function is a piecewise function, a and b are multiple pairs of continuous data, while x2(t), y2(t), z2(t) have different forms with different values ​​of a and b.

[0090] Step S4042: Based on each plane equation and parametric equation, calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated for all triangular face vertices.

[0091] Specifically, by simultaneously solving the equations of each plane and the parametric equations, we can obtain the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis, where all the vertices of the triangular faces are located.

[0092] Step S405: Based on the size compensation function, the coordinate values ​​of the scaling reference center, the coordinate values ​​of each intersection point, and each initial coordinate value, determine the target additive manufacturing part model after size compensation and scaling.

[0093] Specifically, step S405 includes:

[0094] Step S4051: Determine the compensation scaling factor based on the coordinate values ​​of each intersection point and the size compensation function.

[0095] Specifically, using the size compensation function shown in the above relationship (1), and combining the obtained coordinate values ​​of each intersection point, the corresponding compensation scaling factor can be calculated. The following relation (5) is shown:

[0096]

[0097] In the formula: (x intersect ,y intersect ,z intersect () represents the coordinates of the intersection point.

[0098] Step S4052: Based on the compensation scaling factor, the scaling reference center coordinate value, and each initial coordinate value, determine the target coordinate value of each triangle vertex after size compensation scaling.

[0099] Specifically, the target coordinate values ​​of each triangle vertex after size compensation scaling can be calculated using the following relationship (6):

[0100]

[0101] In the formula: c′ represents the target coordinate value of the triangle vertex in the corresponding coordinate axis direction after size compensation scaling; c orisbase This indicates the coordinate value of the scaling reference center along the corresponding coordinate axis; c ori This represents the initial coordinate value in the corresponding coordinate axis direction.

[0102] Step S4053: Determine the target additive manufacturing part model after size compensation scaling based on each target coordinate value.

[0103] Specifically, each target coordinate value obtained is used as the coordinate value of each vertex of the triangle face after the additive manufacturing part model to be compensated and scaled is scaled, and the corresponding target additive manufacturing part model after size compensation and scaling is formed.

[0104] Step S406: The target additive manufacturing part model is processed using selective laser sintering technology.

[0105] Specifically, selective laser sintering technology is used to process the target additive manufacturing part model after size compensation and scaling, which improves the dimensional accuracy of the additive manufacturing part model to be compensated and scaled while also improving its appearance.

[0106] The dimension compensation and scaling method for additive manufacturing part models provided in this embodiment calculates the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and scaled within the additive manufacturing part model by combining the plane equation of each plane and the parametric equation of the reference axis. Then, the compensation scaling coefficient based on the dimension compensation function can be calculated using the intersection point coordinates and the dimension compensation function. Furthermore, the compensation scaling coefficient is used as the compensation scaling coefficient of the additive manufacturing part model to be compensated and scaled, and the dimension compensation and scaling of the model is performed. Finally, selective laser sintering technology is used to process the dimensionally compensated and scaled target additive manufacturing part model, which can ensure that the coordinate values ​​of the planes composed of the original triangular faces perpendicular to the coordinate axis to be compensated remain consistent in the direction of the coordinate axis after compensation. This improves both the dimensional accuracy and the appearance of the additive manufacturing part model to be compensated and scaled.

[0107] In one example, a method for dimensional compensation scaling of a workpiece data model is provided, such as... Figure 5 As shown, 1. includes the following steps:

[0108] Step 01: Read the initial coordinate values ​​of all triangle face vertices of the workpiece (stl) to be compensated and scaled in the forming space coordinate system.

[0109] Step 02: Read the size compensation function and scaling reference center for the coordinate axis to be compensated;

[0110] Step 03: Set the reference axis of the STL file to be compensated for the direction of the coordinate axis to be compensated;

[0111] Step 04: Calculate the coordinates of the intersection points of the plane perpendicular to the coordinate axis to be compensated and the corresponding reference axis for each point in the STL file;

[0112] Step 05: Calculate the scaling compensation coefficient based on the coordinate values ​​of the intersection points calculated in Step 04 and the size compensation function of the coordinate axis direction to be compensated read in Step 02;

[0113] Step 06: Calculate the coordinates of a single point after STL scaling compensation based on the scaling compensation coefficient obtained in Step 05 and the scaling reference center read in Step 02;

[0114] Step 07: Use the point coordinates obtained in Step 06 as the vertex coordinates of the triangle face in the compensated STL file, re-output the STL file, and use the output STL file for processing.

[0115] The method for dimensional compensation and scaling of part data models provided in this example sets a separate reference axis when performing dimensional scaling compensation on a single workpiece in a single axis direction. It calculates the coordinates of the intersection points of the plane perpendicular to the coordinate axis to be compensated and the corresponding reference axis for each point in a single STL file. Based on the coordinates of the intersection points, it calculates the scaling factor based on the dimensional scaling function, which is used as the scaling factor at the point coordinates in the original STL file for scaling compensation. This ensures that the coordinate values ​​of the plane composed of the triangular faces perpendicular to the coordinate axis to be compensated remain consistent in that coordinate axis direction after compensation, thereby improving the dimensional accuracy of the formed workpiece while also improving its appearance.

[0116] Furthermore, based on the method for dimensional compensation and scaling of the part data model provided in the above examples, a specific embodiment is provided, including:

[0117] Step 01: Read the initial coordinate values ​​of all triangle vertices of the 45 compensated and scaled STLs in the forming space coordinate system. The dimensions of the axis-aligned bounding box of the forming space geometry, determined by the forming chamber hardware, are 350mm*350mm*430mm. The origin of the Cartesian coordinate system established in the forming space is located at the intersection of the center line of the vertical horizontal plane of the axis-aligned bounding box of the forming space geometry determined by the forming chamber hardware and the lowest horizontal plane of the space used by the forming chamber for forming the workpiece. Store the coordinate values ​​of all triangle vertices of a single STL in a multi-row, 3-column array. The first column of the array is the initial x-coordinate of the triangle vertex, the second column is the initial y-coordinate of the triangle vertex, and the third column is the initial z-coordinate of the triangle vertex. The top and right views of the 45 compensated and scaled STLs in the forming space are shown below. Figure 6A and Figure 6B As shown.

[0118] Step 02: Read the z-axis dimension compensation function. The z-axis dimension compensation function is obtained based on the fixed scaling center point. The fixed scaling center is located at the intersection of the center line of the vertical horizontal plane of the bounding box of the forming space geometry determined by the forming chamber hardware and the lowest horizontal plane of the space used by the forming chamber to form the workpiece, that is, the origin of the coordinate system, with coordinate values ​​of (0, 0, 0).

[0119] The intersection point of the centerline of the vertical horizontal plane of the axis-aligned bounding box of the molding space geometry determined by the molding chamber hardware and the lowest horizontal plane of the space in the molding chamber used for molding the workpiece is as follows: Figure 7 As shown.

[0120] Furthermore, the dimension compensation function in the z-axis direction is shown in the following equation (7):

[0121] R (x,y,z)=1.037833985+0.0000010968*x*y-0.0000016387*x 2 *y-0.000052639*x+0.0000006452*x*z-0.0000016387*x 2 *z+0.0001511478*y+0.0000006452*y*z-0.0018273852*z-0.0000016387*x 3 -0.0000016387*y 2 *z-0.0000842579*x 2 -0.0000065548*y 3 -0.0000655483*y 2 -0.0000032774*z 3 +0.0001307739*z 2 (7)

[0122] In the formula: x, y, z represent the original coordinates of any point in the forming space coordinate system; R (x,y,z) This represents the compensation scaling factor along the coordinate axis of a point whose original coordinates are x, y, z in the forming space coordinate system.

[0123] Furthermore, when reading the scaling reference center of the triangle face vertices in the scaling STL file, the scaling reference center is the same as the fixed scaling center point on which the z-axis size compensation function is based, i.e., the origin of the coordinate system, with coordinate values ​​of (0, 0, 0).

[0124] Step 03: Set the reference axis of a single STL file to be compensated in the z-coordinate direction as the center line of the STL model's axis-aligned bounding box in the z-coordinate direction. The calculation method is to calculate the maximum and minimum values ​​of each column of the array of all triangle face vertices of the stored single STL, and take the average of the maximum and minimum values ​​as the center coordinate value of the minimum axis-aligned bounding box. Based on the coordinate values, construct the parametric equation of the reference axis of the single STL file in the z-coordinate direction, as shown in the following relationship (8):

[0125]

[0126] In the formula: x3, y3, z3 represent the coordinate values ​​of a point on the reference axis in the z-coordinate direction of a single STL file to be compensated; x oribc y oribc , z oribc This represents the coordinates of the center point of the minimum axis-aligned bounding box of a single STL file to be compensated.

[0127] Step 04: Calculate the coordinates of the intersection point of the plane perpendicular to the z-axis and the corresponding reference axis of a single point in the STL file. The general equation expression of the plane perpendicular to the z-axis where the coordinates of a single point are located is shown in the following relation (9):

[0128] zz ori =0 (9)

[0129] In the formula: z represents the z-coordinate value of a point on a plane perpendicular to the z-coordinate axis; z ori This represents the initial z-coordinate value of a single point in the shaped space.

[0130] Furthermore, by simultaneously solving the parametric equations of the reference axis in the z-coordinate direction of a single STL file and the general equation of the plane perpendicular to the z-coordinate direction where the coordinates of a single point lie, the coordinates of the intersection point are obtained, as shown in the following relationship (10):

[0131] (x intersect ,y intersect ,z intersect )=(x oribc ,y oribc ,z ori (10)

[0132] In the formula: (x intersect ,y intersect ,z intersect This represents the coordinates of the intersection point of the reference axis in the z-axis direction and the plane perpendicular to the z-axis where the single point is located in a single STL file to be compensated; x oribc y oribc This represents the coordinates of the center point of the minimum axis-aligned bounding box of a single STL file to be compensated, on the x and y axes.

[0133] Among them, the STL triangle face vertices, the plane perpendicular to the z-coordinate axis where the vertices are located, the centerline of the STL minimum axis-aligned bounding box in the z-coordinate axis direction, and the intersection of the plane and the centerline are as follows: Figure 8 As shown.

[0134] Step 05: Calculate the compensation scaling factor at the coordinates of a single intersection point using the following relationship (11):

[0135]

[0136] Step 06: Use the z-axis scaling factor calculated at the intersection point as the z-axis scaling factor at the original vertex of the STL triangle face, and calculate the compensated z-coordinate value. The calculation formula is shown in the following relation (12):

[0137]

[0138] In the formula: z′ represents the coordinate value of the vertices of the triangle face in the STL file after compensation along the z-axis, calculated using the size compensation function of the intersection points in the corresponding coordinate axis directions; z ori This represents the original coordinates of the STL triangle vertex along the z-axis.

[0139] Step 07: Traverse all vertices of a single STL file, repeat steps 04 to 06, calculate the compensated z-coordinate value for each vertex, and store all the calculated compensated z-coordinate values ​​in a multi-row array with one column.

[0140] Step 08: Traverse all STL files to be compensated, repeat steps 03 to 07, and calculate the compensated z-coordinate value of each vertex of all STL files to be compensated.

[0141] Step 09: Combine the first and second columns of the array of all triangle vertex coordinates read in Step 01 with the compensated z-coordinate values ​​into a multi-row, 3-column array, which serves as the coordinates of all triangle vertices in the compensated single STL file. Re-output the STL file and use the output STL file for processing.

[0142] Furthermore, the z-direction error between the actual workpiece dimensions at multiple locations within the forming space and the dimensions shown in the drawing remained within ±0.3mm, as shown in Table 2 below:

[0143] Table 2. Dimensional errors of measured distances along the z-axis of 45 STL workpieces at multiple locations within the forming space after actual machining.

[0144]

[0145]

[0146] Furthermore, after the plane composed of the original triangular faces perpendicular to the z-axis is compensated, the coordinate values ​​in the z-axis direction remain consistent, resulting in a significant improvement in the surface quality of the formed workpiece.

[0147] This embodiment also provides a size compensation and scaling device for an additive manufacturing part model, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0148] This embodiment provides a size compensation and scaling device for additive manufacturing part models, such as... Figure 9 As shown, the device includes:

[0149] The first acquisition module 901 is used to acquire the initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the size compensation function and scaling reference center coordinate values ​​in the direction of the coordinate axis to be compensated. The forming space coordinate system represents the Cartesian coordinate system established in the forming space determined by the forming chamber hardware used to form the workpiece in the forming equipment. The origin of the coordinate system is located at any point in the forming space.

[0150] The second acquisition module 902 is used to acquire the objective function that increases monotonically in the direction of the coordinate axis to be compensated. The objective function is either a continuous function or a piecewise function.

[0151] The first determining module 903 is used to determine the reference axis of the additive manufacturing part model to be compensated in the direction of the coordinate axis to be compensated based on the objective function.

[0152] The calculation module 904 is used to calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated for scaling.

[0153] The second determining module 905 is used to determine the target additive manufacturing part model after compensation and scaling based on the size compensation function, the coordinate value of the scaling reference center, the coordinate value of each intersection point and each initial coordinate value.

[0154] In some alternative implementations, the computing module 904 includes:

[0155] The acquisition submodule is used to obtain the plane equations for each plane and the parametric equations of the objective function corresponding to the datum axis.

[0156] The calculation submodule is used to calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated, based on the plane equation and parametric equation.

[0157] In some alternative implementations, the second determining module 905 includes:

[0158] The first determination submodule is used to determine the compensation scaling factor based on the coordinate values ​​of each intersection point and the size compensation function.

[0159] The second determining submodule is used to determine the target coordinate value of each triangle vertex after size compensation scaling based on the compensation scaling factor, the scaling reference center coordinate value, and each initial coordinate value.

[0160] The third determination submodule is used to determine the target additive manufacturing part model after size compensation scaling based on each target coordinate value.

[0161] In some alternative implementations, the parametric equation of the objective function is expressed as:

[0162]

[0163] In the formula: x2, y2, z2 represent the coordinate values ​​of the reference axis determined by the parametric equation at parameter t; x2(t), y2(t), z2(t) represent the functional relationships between x2, y2, z2 and parameter t, respectively; a, b represent the range of values ​​of parameter t, which are determined by the objective function.

[0164] In some alternative implementations, the second determining submodule is specifically used to determine via the following relation:

[0165]

[0166] In the formula: c′ represents the target coordinate value of the triangle vertex in the corresponding coordinate axis direction after size compensation scaling; c orisbase This represents the coordinate value of the scaling reference center along the corresponding coordinate axis; (x intersect ,y intersect ,z intersect () represents the coordinates of the intersection point; This represents the compensation scaling factor in the corresponding coordinate axis direction; c ori This represents the initial coordinate value in the corresponding coordinate axis direction.

[0167] In some alternative embodiments, the device further includes:

[0168] The processing module is used to process the target additive manufacturing part model using selective laser sintering technology.

[0169] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0170] In this embodiment, the size compensation and scaling device for the additive manufacturing part model is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0171] This invention also provides a computer device having the above-described features. Figure 9 The illustrated size compensation scaling device for the additive manufacturing part model.

[0172] Please see Figure 10 , Figure 10This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 10 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 10 Take a processor 10 as an example.

[0173] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0174] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0175] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0176] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0177] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0178] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0179] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0180] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for dimensional compensation and scaling of an additive manufacturing part model, characterized in that, The method includes: The initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled are obtained in the forming space coordinate system, as well as the size compensation function and the coordinate values ​​of the scaling reference center in the direction of the coordinate axis to be compensated. The forming space coordinate system represents the Cartesian coordinate system established in the forming space determined by the forming chamber hardware used to form the workpiece in the forming equipment. The origin of the coordinate system is located at any point in the forming space. Obtain the objective function that increases monotonically along the coordinate axis to be compensated, wherein the objective function is either a continuous function or a piecewise function; The reference axis of the scaled additive manufacturing part model to be compensated is determined based on the objective function along the coordinate axis to be compensated. Calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additively manufactured part to be compensated, where all the vertices of the triangular faces are located; Based on the size compensation function, the coordinate values ​​of the scaling reference center, the coordinate values ​​of each intersection point, and each initial coordinate value, the target additive manufacturing part model after size compensation and scaling is determined. The calculation of the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additively manufactured part to be compensated, where all the vertices of the triangular faces are located, includes: Obtain the plane equation for each plane and the parametric equation of the objective function corresponding to the reference axis; Based on each of the plane equations and the parametric equations, calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated, where all the vertices of the triangular faces are located.

2. The method according to claim 1, characterized in that, Based on the size compensation function, the coordinates of the scaling reference center, the coordinates of each intersection point, and each initial coordinate value, the target additive manufacturing part model after size compensation and scaling is determined, including: Based on the coordinate values ​​of each intersection point and the size compensation function, the compensation scaling factor is determined; Based on the compensation scaling factor, the scaling reference center coordinate value, and each of the initial coordinate values, determine the target coordinate value of each triangle vertex after size compensation scaling; The target additive manufacturing part model is determined based on the size compensation scaling of each target coordinate value.

3. The method according to claim 1, characterized in that, The parametric equation of the objective function is expressed as: In the formula: ， ， This indicates that the reference axis determined by the parametric equation is in the parameter... The corresponding coordinate value at that time; , , They represent , , With parameters The functional relationship; , Indicates parameters The range of values ​​for is determined by the form of the objective function.

4. The method according to claim 2, characterized in that, Based on the compensation scaling factor, the scaling reference center coordinates, and each initial coordinate value, the target coordinates of each triangle vertex after size compensation scaling are determined, including by: determining the following relationship: In the formula: This represents the target coordinate values ​​of the vertices of the triangle face after size compensation and scaling, in the corresponding coordinate axis direction; This indicates the coordinate value of the scaling reference center in the corresponding coordinate axis direction; Indicates the coordinates of the intersection point; This represents the compensation scaling factor in the corresponding coordinate axis direction; This represents the initial coordinate value in the corresponding coordinate axis direction.

5. The method according to claim 1, characterized in that, The method further includes: The target additive manufacturing part model is processed using selective laser sintering technology.

6. A size compensation and scaling device for an additive manufacturing part model, characterized in that, The device includes: The first acquisition module is used to acquire the initial coordinate values ​​of each triangle vertex of the additive manufacturing part model to be compensated and scaled in the forming space coordinate system, as well as the size compensation function and scaling reference center coordinate values ​​in the direction of the coordinate axis to be compensated. The forming space coordinate system represents the Cartesian coordinate system established in the forming space determined by the forming chamber hardware used to form the workpiece in the forming equipment. The origin of the coordinate system is located at any point in the forming space. The second acquisition module is used to acquire the target function that increases monotonically in the direction of the coordinate axis to be compensated, wherein the target function is either a continuous function or a piecewise function. The first determining module is used to determine the reference axis of the scaled additive manufacturing part model to be compensated in the direction of the coordinate axis to be compensated based on the objective function; The calculation module is used to calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additively manufactured part to be compensated, where all the vertices of the triangular faces are located; The second determining module is used to determine the target additive manufacturing part model after compensation and scaling based on the size compensation function, the coordinate value of the scaling reference center, the coordinate value of each intersection point and each initial coordinate value. The computing module includes: The acquisition submodule is used to acquire the plane equation of each plane and the parametric equation of the objective function corresponding to the reference axis; The calculation submodule is used to calculate the coordinates of the intersection points of each plane perpendicular to the direction of the coordinate axis to be compensated and the reference axis within the model of the additive manufacturing part to be compensated, based on each plane equation and the parametric equation.

7. A computer device, characterized in that, include: A memory and a processor are communicatively connected, the memory storing computer instructions, and the processor executing the computer instructions to perform the dimensional compensation scaling method for the additive manufacturing part model according to any one of claims 1 to 6.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the dimensional compensation scaling method for the additive manufacturing part model according to any one of claims 1 to 5.

9. A computer program product, characterized in that, Includes computer instructions for causing a computer to perform the dimensional compensation scaling method for an additive manufacturing part model as described in any one of claims 1 to 5.

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