Output correction method and system for multi-field coupling three-dimensional printing

Abstract

The invention relates to the technical field of three-dimensional printing control, and particularly discloses an output correction method and system for multi-field coupling three-dimensional printing, and the method comprises the steps: obtaining an actual printing progress at regular time, activating a shooting point, and obtaining an actual observation image based on the activated shooting point; acquiring multi-field data according to a sensor arranged in a printer, and determining a printing speed according to the multi-field data; and establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjusting the printing speed according to the comparison result. The shooting point is introduced into the printer, the actual image is obtained through the shooting point, the theoretical image at the shooting point is determined according to the to-be-printed model, the theoretical image and the actual image are compared, whether the current printing state meets the theoretical state or not can be judged, then the printing speed is adjusted, and the printing accuracy of three-dimensional printing is extracted.

Description

Technical Field

[0001] The present invention relates to the field of three-dimensional printing control technology, and in particular to an output correction method and system for multi-field coupling three-dimensional printing. Background Art

[0002] Three-dimensional printing (3D printing) is a layer-by-layer manufacturing technology, also known as additive manufacturing (AM). It is the opposite of traditional subtractive manufacturing, building objects by stacking materials layer by layer instead of cutting or processing solid materials to form the final shape.

[0003] During the 3D printing process, a variety of sensors will be built into the printer to construct a multi-field coupled 3D printing architecture. In the existing multi-field coupled 3D printing (Multiphysics Coupled 3D Printing), "multi-field" refers to the coupling and mutual influence of multiple physical fields. These physical fields work together on different aspects of the 3D printing process, affecting the quality, speed and final performance of the printing, including thermal fields, mechanical fields, fluid fields and electromagnetic fields, etc. Most of these fields are conventional physical fields. In fact, with the advancement of technology, the "field" of multi-field coupled 3D printing technology can be further expanded, and visual monitoring parameters can be introduced into the existing printing process as a "visual field" to optimize the printing process.

[0004] Therefore, how to introduce a visual inspection process into the existing technical solution to correct the printing process is the technical problem that the technical solution of the present invention aims to solve. Summary of the invention

[0005] The object of the present invention is to provide an output correction method and system for multi-field coupling three-dimensional printing to solve the problems raised in the above background technology.

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

[0007] An output correction method for multi-field coupling three-dimensional printing, the method comprising:

[0008] Shooting points are evenly arranged on the circumference of the printer, and observation points corresponding to the shooting points are arranged in the model to be printed according to the positional relationship between the model to be printed and the printer;

[0009] Obtain theoretical observation images of each observation point under different printing progress;

[0010] During the actual printing process, the actual printing progress is obtained at regular intervals, the shooting points are activated, and the actual observation images are obtained based on the activated shooting points;

[0011] Acquire multiple fields of data according to a sensor built into the printer, and determine a printing speed according to the multiple fields of data;

[0012] A printed model is established according to the actual printing progress, the actual observation image of each shooting point is compared with the theoretical observation image of the corresponding observation point, and the printing speed is adjusted according to the comparison result.

[0013] As a further solution of the present invention: the step of evenly setting shooting points on the circumference of the printer and setting observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer comprises:

[0014] Determine the number of shooting points based on the printer's resources;

[0015] Get the number of circumferences of the printer, divide the number of shooting points by the number of circumferences and round down to get the number of shooting points on each circumference;

[0016] For any circumferential surface, a dynamic-size grid is constructed with the endpoints of the circumferential surface as base points, and the number of grid points in the circumferential surface is obtained; the dynamic size is the side length of the grid unit;

[0017] Keep increasing the dynamic size until the number of grid points is less than the number of shooting points on the surface, and then output the current grid;

[0018] Read the grid points of the current grid as shooting points;

[0019] Taking the bottom surface of the model to be printed as the reference, insert the reference planes corresponding to the peripheral surfaces of the printer, and select the observation points corresponding to the shooting points in the reference planes.

[0020] As a further solution of the present invention: the step of obtaining theoretical observation images of each observation point under different printing progresses includes:

[0021] Add model hiding mask;

[0022] Get the printing range under different printing progress in the preset printing order;

[0023] Select an area in the model hidden mask based on the printing range, delete the selected area in the model hidden mask, and obtain the printed model under different printing progress;

[0024] For any printing progress, an image pointing in the direction of the center of the printed model is obtained at each observation point as a theoretical observation image.

[0025] As a further solution of the present invention: in the actual printing process, the steps of regularly acquiring the actual printing progress, activating the shooting points, and acquiring the actual observation image based on the activated shooting points include:

[0026] During the actual printing process, the actual printing progress is obtained regularly;

[0027] Randomly select shooting points and activate them;

[0028] An image pointing to the center of the to-be-printed model is acquired based on the activated shooting point to obtain an actual observation image;

[0029] Among them, the selection probability of each shooting point is:

[0030] Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth surface is selected before the current printing time; K is the number of surfaces.

[0031] As a further solution of the present invention: the step of establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjusting the printing speed according to the comparison result includes:

[0032] Read the printed model according to the actual printing progress;

[0033] Select shooting points in sequence and read the actual observation images at the shooting points;

[0034] Query the observation point corresponding to the selected shooting point and read the theoretical observation image of the observation point;

[0035] Perform contour recognition on both the actual observation image and the theoretical observation image to obtain the model contour;

[0036] A difference contour segment is determined according to the model contour, and a printing speed is adjusted according to the difference contour segment.

[0037] As a further solution of the present invention: the step of determining the difference contour segment according to the model contour and adjusting the printing speed according to the difference contour segment comprises:

[0038] Get the center of the printed model, and construct a spherical ray group in a preset direction with the center as the starting point;

[0039] On any ray, query the contour points in the actual observation image and the contour points in the theoretical observation image, and the difference between the two contour points on the ray;

[0040] Contour points whose statistical difference is greater than a preset threshold are marked as difference contour segments;

[0041] Count the total length of the difference contour segments in the printed model, and adjust the printing speed according to the total length and actual printing progress;

[0042] The adjustment range of the printing speed is as follows according to the total length and actual printing progress:

[0043] Where F is the adjustment range of the printing speed, β is the preset correction coefficient, L is the total length of the difference contour segment, and S is the actual printing progress.

[0044] The technical solution of the present invention also provides an output correction system for multi-field coupled three-dimensional printing, the system comprising:

[0045] A point position preset module is used to evenly set shooting points on the circumference of the printer, and to set observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer;

[0046] Theoretical image determination module, used to obtain theoretical observation images of each observation point under different printing progress;

[0047] An actual image determination module is used to obtain the actual printing progress at regular intervals during the actual printing process, activate the shooting points, and obtain the actual observation image based on the activated shooting points;

[0048] A multi-field coupling application module, used to obtain multi-field data according to a sensor built into the printer, and determine a printing speed according to the multi-field data;

[0049] The correction module is used to establish a printed model according to the actual printing progress, compare the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjust the printing speed according to the comparison result.

[0050] As a further solution of the present invention: the point preset module includes:

[0051] A quantity determination unit, used for determining the number of shooting points according to the resource quantity of the printer;

[0052] The point calculation unit is used to obtain the number of the peripheral surface of the printer, and the number of shooting points is divided by the number of peripheral surfaces and rounded down to obtain the number of shooting points on each peripheral surface;

[0053] A grid application unit is used to construct a grid of dynamic size for any circumference with the endpoints of the circumference as base points, and obtain the number of grid points in the circumference; the dynamic size is the side length of the grid unit;

[0054] A grid output unit is used to continuously increase the dynamic size until the number of grid points is less than the number of shooting points on the circumference, and output the current grid;

[0055] A shooting point output unit is used to read the grid points of the current grid as shooting points;

[0056] The observation point selection unit is used to insert reference surfaces corresponding to the peripheral surfaces of the printer based on the bottom surface of the model to be printed, and select observation points corresponding to the shooting points in the reference surfaces.

[0057] As a further solution of the present invention: the theoretical image determination module includes:

[0058] Mask adding unit, used to add model hidden mask;

[0059] A range acquisition unit, used to acquire the printing range under different printing progress in a preset printing order;

[0060] A mask deletion unit is used to select an area in the model hidden mask based on the printing range, delete the selected area in the model hidden mask, and obtain a printed model under different printing progress;

[0061] The first acquisition unit is used to acquire, for any printing progress, an image pointing in the direction of the center of the printed model at each observation point as a theoretical observation image.

[0062] As a further solution of the present invention: the actual image determination module includes:

[0063] A progress acquisition unit, used to regularly acquire the actual printing progress during the actual printing process;

[0064] A shooting point activation unit, used to randomly select shooting points and activate them;

[0065] A second acquisition unit is used to acquire an image pointing to the center of the to-be-printed model based on the activated shooting point to obtain an actual observation image;

[0066] Among them, the selection probability of each shooting point is:

[0067] Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth surface is selected before the current printing time; K is the number of surfaces.

[0068] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention introduces shooting points in the printer, obtains actual images from the shooting points, and determines the theoretical image at the shooting points according to the model to be printed. By comparing the theoretical image and the actual image, it can be determined whether the current printing state conforms to the theoretical state, and then the printing speed is adjusted to extract the printing accuracy of three-dimensional printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention.

[0070] Figure 1 A flowchart of an output correction method for multi-field coupled 3D printing.

[0071] Figure 2 The first sub-flow chart of the output correction method for multi-field coupling 3D printing is shown.

[0072] Figure 3 The second sub-process flowchart of the output correction method for multi-field coupling three-dimensional printing.

[0073] Figure 4 The third sub-process flowchart of the output correction method for multi-field coupling three-dimensional printing.

[0074] Figure 5 This is a fourth sub-process flowchart of the output correction method for multi-field coupling three-dimensional printing.

[0075] Figure 6 The structure block diagram of the output correction system for multi-field coupled 3D printing. DETAILED DESCRIPTION

[0076] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0077] Figure 1 The flowchart of the output correction method for multi-field coupling 3D printing is as follows. In an embodiment of the present invention, an output correction method for multi-field coupling 3D printing includes:

[0078] Step S100: evenly setting shooting points on the circumference of the printer, and setting observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer;

[0079] A 3D printer generally has six circumferential surfaces, namely, two bottom surfaces, and four side surfaces, left, right, front, and back. Shooting points are evenly arranged on the six circumferential surfaces, and image acquisition devices are installed at the shooting points. The working process of the image acquisition device is generally in the form of flash photography, that is, shooting when receiving a shooting instruction or shooting at a preset frequency.

[0080] After the shooting point is determined, the point corresponding to the shooting point is marked in the model to be printed, which is called the observation point. This process is not complicated. Align the bottom center of the model to be printed with the bottom center of the 3D printer to determine the corresponding relationship, obtain the azimuth and distance of the shooting point relative to the bottom center of the printer, and then obtain the point at the same azimuth and distance based on the bottom center of the model to be printed, which is the observation point.

[0081] In layman's terms, the process of generating observation points is to add points corresponding to the actual shooting points in the model to be printed.

[0082] Step S200: obtaining theoretical observation images of each observation point under different printing progress;

[0083] Before the 3D printer executes a printing task, it will analyze the model to be printed and generate a task list. These task lists are segmented, that is, how much content is printed at a time. Each section is called a printing progress. The printing progress is expressed in percentages, 0% means just starting to print, 50% means halfway completed, and 100% means printing is complete. The printing progress is a fixed parameter of the 3D printer and is regarded as known data in the technical solution of this application.

[0084] It should be noted that the printing progress is discrete, generally jumping in units of 1%. If you want higher accuracy, you can set the unit to 0.1% or 0.01%.

[0085] The theoretical observation images at each observation point under different printing progress are obtained. This process occurs in the model and is very simple. Connect the observation point and the center to get a straight line, obtain a plane perpendicular to the straight line, and then look directly at the plane and adjust the zoom ratio. The model observed under the printing progress is the theoretical observation image.

[0086] Step S300: During the actual printing process, the actual printing progress is obtained at regular intervals, the shooting points are activated, and the actual observation images are obtained based on the activated shooting points;

[0087] During the actual printing process, the 3D printer will display the printing progress in real time, which is called the actual printing progress. Every time the actual printing progress jumps, a shooting point is activated, and the actual observation image is obtained by the activated shooting point.

[0088] In step S200, the theoretical observation image under each printing progress has been obtained, and by comparing the actual observation image with the theoretical observation image, it can be determined whether the printing process is normal from a visual perspective.

[0089] Step S400: acquiring multiple fields of data according to a sensor built into the printer, and determining a printing speed according to the multiple fields of data;

[0090] There are many sensors inside the 3D printer, such as temperature sensors and humidity sensors, which are used to obtain the temperature and humidity inside the printer. Each type of data is represented by a separate matrix, called field data, such as temperature field data and humidity field data. Based on this data, the printing speed can be determined in real time.

[0091] It should be noted that step S400 is actually a prior art. Existing 3D printers are equipped with sensors and application algorithms of sensor data, which can dynamically determine the printing speed.

[0092] Step S500: establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjusting the printing speed according to the comparison result;

[0093] A printed model is established according to the actual printing progress. The printed model is a part of the complete model to be printed, and the establishment process is not difficult. Its function is to count the shooting and analysis results of all shooting points. Since the number of shooting points is not unique, it will be very cumbersome to set up a separate analysis process for each shooting point. Converting it to a unified model (printed model) can greatly simplify the difficulty of data analysis without considering the situation of each shooting point.

[0094] By comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, the printed model is adjusted, and the printing speed is determined according to the adjusted printed model. The visual analysis process is introduced into the original multi-field coupling analysis process, which greatly improves the adaptability of the printing speed and optimizes the correction effect.

[0095] Among them, the correction process refers to adjusting the printing speed.

[0096] Figure 2 The first sub-flow chart of the output correction method for multi-field coupling 3D printing is provided, wherein the steps of evenly setting shooting points on the circumference of the printer and setting observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer include:

[0097] Step S101: determining the number of shooting points according to the resource amount of the printer;

[0098] Step S102: Obtain the number of circumferences of the printer, divide the number of shooting points by the number of circumferences and round down to get the number of shooting points on each circumference;

[0099] Step S103: for any circumferential surface, a grid of dynamic size is constructed with the endpoints of the circumferential surface as base points, and the number of grid points in the circumferential surface is obtained; the dynamic size is the side length of the grid unit;

[0100] Step S104: continuously increasing the dynamic size until the number of grid points is less than the number of shooting points on the circumference, and outputting the current grid;

[0101] Step S105: reading the grid points of the current grid as shooting points;

[0102] Step S106: Taking the bottom surface of the model to be printed as a reference, insert reference surfaces corresponding to the peripheral surfaces of the printer, and select observation points corresponding to the shooting points in the reference surfaces.

[0103] The above content limits the process of setting shooting points and observation points, which are described as follows:

[0104] Shooting points: Determine the number of shooting points based on the resources of the printer. The more shooting points there are, the more resources are required. The shooting points need to be evenly distributed on each circumference of the printer. The number of shooting points on each circumference can be obtained by dividing the number of shooting points by the number of circumferences (usually six) and then rounding down.

[0105] A grid is set on each circumferential surface, and the grid units are continuously enlarged. As the magnification increases, the number of grid nodes in the circumferential surface will become smaller and smaller until it is less than the number of shooting points on the circumferential surface. When the number of grid nodes is less than the number of shooting points on the circumferential surface, the enlargement process stops and the grid is output; at this time, the grid points of the grid are the shooting points.

[0106] In the software, take the bottom surface of the model to be printed as the reference, insert reference surfaces corresponding to the peripheral surfaces of the printer, usually six, and select the observation point corresponding to the shooting point in the reference surface according to the orientation and distance.

[0107] Figure 3 The second sub-flow chart of the output correction method for multi-field coupling 3D printing is as follows. The step of obtaining theoretical observation images of each observation point under different printing progresses includes:

[0108] Step S201: Add model hiding mask;

[0109] Step S202: obtaining the printing range under different printing progress in a preset printing order;

[0110] Step S203: selecting an area in the model hidden mask based on the printing range, deleting the selected area in the model hidden mask, and obtaining a printed model under different printing progress;

[0111] Step S204: For any printing progress, an image pointing in the direction of the center of the printed model is obtained at each observation point as a theoretical observation image.

[0112] The above content provides a specific theoretical observation image generation process. First, a model hidden mask is generated to hide the entire model to be printed. Then, the printed range is obtained under different printing progress, and the mask within the range is deleted (at this time, the hidden range is no longer hidden, and the effect is displayed). Then, the printing range can be displayed in the model to be printed. This process is essentially a display processing process. In the field of image processing, this idea is often used and belongs to the migration application of image processing technology.

[0113] Finally, after the displayed part of the model is determined by the printing progress, an image pointing in the direction of the center of the printed model is obtained at each observation point as a theoretical observation image.

[0114] Figure 4 The third sub-flow chart of the output correction method for multi-field coupling 3D printing is shown in the figure. In the actual printing process, the steps of regularly obtaining the actual printing progress, activating the shooting points, and obtaining the actual observation image based on the activated shooting points include:

[0115] Step S301: During the actual printing process, the actual printing progress is obtained regularly;

[0116] Step S302: randomly select a shooting point and activate it;

[0117] Step S303: acquiring an image pointing to the center of the to-be-printed model based on the activated shooting point to obtain an actual observation image.

[0118] In the actual printing stage, the actual printing progress is obtained regularly, and some shooting points are randomly selected and activated. The purpose of random selection is to reduce resource consumption. The image pointing to the center of the model to be printed can be obtained according to the selected shooting points.

[0119] The key point in the above content is the selection process of the shooting points, where the selection probability of each shooting point is:

[0120] Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth surface is selected before the current printing time; K is the number of surfaces.

[0121] The logic for determining the selection probability is: if a shooting point has not been selected for a long time, then its probability of being selected will be greater, and the longer the time, the greater the probability of being selected; further, considering the diversity of shooting, the more angles the better, therefore, for each shooting point, the number of selections of shooting points with the same coordinates in all circumferences is obtained, the greater the number of selections, the smaller the probability of the shooting point being selected; finally, the result can be corrected by a pre-set coefficient.

[0122] Figure 5 The fourth sub-flow diagram of the output correction method for multi-field coupling 3D printing is as follows: the steps of establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjusting the printing speed according to the comparison result include:

[0123] Step S501: reading the printed model according to the actual printing progress;

[0124] Step S502: selecting shooting points in sequence and reading actual observation images at the shooting points;

[0125] Step S503: querying the observation point corresponding to the selected shooting point, and reading the theoretical observation image of the observation point;

[0126] Step S504: performing contour recognition on both the actual observation image and the theoretical observation image to obtain a model contour;

[0127] Step S505: determining a difference contour segment according to the model contour, and adjusting the printing speed according to the difference contour segment.

[0128] The above content specifically describes the application process of the actual observation image and the theoretical observation image. First, the printed model (the theoretical state under different printing progress in step S203) is read as the reference model according to the actual printing progress; then, the shooting points are selected in turn, the actual observation image at the shooting point is read, and the theoretical observation image at the corresponding observation point is queried synchronously, and contour recognition is performed on the actual observation image and the theoretical observation image to obtain the contour of the printed model in the image, which is called the model contour; finally, the model contour in the actual observation image and the model contour in the theoretical observation image are compared to determine the difference part, which is called the difference contour segment. The difference contour segment is the position in the printing process that is inconsistent with the theoretical situation. The printing speed is adjusted based on the difference contour segment. On the basis of the original multi-field coupling, a vision-based adjustment process is introduced.

[0129] Specifically, the step of determining the difference contour segment according to the model contour and adjusting the printing speed according to the difference contour segment includes:

[0130] Get the center of the printed model, and construct a spherical ray group in a preset direction with the center as the starting point;

[0131] On any ray, query the contour points in the actual observation image and the contour points in the theoretical observation image, and the difference between the two contour points on the ray;

[0132] Contour points whose statistical difference is greater than a preset threshold are marked as difference contour segments;

[0133] Count the total length of the difference contour segments in the printed model, and adjust the printing speed according to the total length and actual printing progress;

[0134] The adjustment range of the printing speed is as follows according to the total length and actual printing progress:

[0135] Where F is the adjustment range of the printing speed, β is the preset correction coefficient, L is the total length of the difference contour segment, and S is the actual printing progress.

[0136] The above content defines the process of adjusting the printing speed according to the difference contour segment. First, a spherical ray group is created based on the center of the printed model, and the distance between the model contours in the two images on any ray (the difference on the ray) is obtained. If the distance is large enough, the intersection of the ray and the model contour is marked as a contour point, and all marked contour points are counted to obtain the difference contour segment.

[0137] Finally, the printing speed can be adjusted according to the total length of the difference contour segment and the actual printing progress.

[0138] It should be noted that the printing speed is adjusted in this application to reduce the printing speed. The lower the printing speed, the smaller the probability of risk and the better the printing effect. The extent of reducing the printing speed is the above-mentioned adjustment range, which is directly proportional to the ratio of the total length to the actual printing progress. Combined with the preset correction coefficient, the adjustment range can be adjusted to within the preset range.

[0139] Figure 6 The output correction system for multi-field coupling 3D printing is a structural block diagram of the components. In an embodiment of the present invention, an output correction system for multi-field coupling 3D printing is provided. The system 10 includes:

[0140] The point position preset module 11 is used to evenly set shooting points on the circumference of the printer, and to set observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer;

[0141] Theoretical image determination module 12, used to obtain theoretical observation images of each observation point under different printing progress;

[0142] The actual image determination module 13 is used to obtain the actual printing progress at regular intervals during the actual printing process, activate the shooting points, and obtain the actual observation image based on the activated shooting points;

[0143] A multi-field coupling application module 14, used to obtain multi-field data according to a sensor built into the printer, and determine a printing speed according to the multi-field data;

[0144] The correction module 15 is used to establish a printed model according to the actual printing progress, compare the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjust the printing speed according to the comparison result.

[0145] Furthermore, the point preset module 11 includes:

[0146] A quantity determination unit, used for determining the number of shooting points according to the resource quantity of the printer;

[0147] The point calculation unit is used to obtain the number of the peripheral surface of the printer, and the number of shooting points is divided by the number of peripheral surfaces and rounded down to obtain the number of shooting points on each peripheral surface;

[0148] A grid application unit is used to construct a grid of dynamic size for any circumference with the endpoints of the circumference as base points, and obtain the number of grid points in the circumference; the dynamic size is the side length of the grid unit;

[0149] A grid output unit is used to continuously increase the dynamic size until the number of grid points is less than the number of shooting points on the circumference, and output the current grid;

[0150] A shooting point output unit is used to read the grid points of the current grid as shooting points;

[0151] The observation point selection unit is used to insert reference surfaces corresponding to the peripheral surfaces of the printer based on the bottom surface of the model to be printed, and select observation points corresponding to the shooting points in the reference surfaces.

[0152] Specifically, the theoretical image determination module 12 includes:

[0153] Mask adding unit, used to add model hidden mask;

[0154] A range acquisition unit, used to acquire the printing range under different printing progress in a preset printing order;

[0155] A mask deletion unit is used to select an area in the model hidden mask based on the printing range, delete the selected area in the model hidden mask, and obtain a printed model under different printing progress;

[0156] The first acquisition unit is used to acquire, for any printing progress, an image pointing in the direction of the center of the printed model at each observation point as a theoretical observation image.

[0157] In addition, the actual image determination module 13 includes:

[0158] A progress acquisition unit, used to regularly acquire the actual printing progress during the actual printing process;

[0159] A shooting point activation unit, used to randomly select shooting points and activate them;

[0160] A second acquisition unit is used to acquire an image pointing to the center of the to-be-printed model based on the activated shooting point to obtain an actual observation image;

[0161] Among them, the selection probability of each shooting point is:

[0162] Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth surface is selected before the current printing time; K is the number of surfaces.

[0163] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An output correction method for multi-field coupling 3D printing, characterized in that: The method comprises: Shooting points are evenly arranged on the circumference of the printer, and observation points corresponding to the shooting points are arranged in the model to be printed according to the positional relationship between the model to be printed and the printer; Obtain theoretical observation images of each observation point under different printing progress; During the actual printing process, the actual printing progress is obtained at regular intervals, the shooting points are activated, and the actual observation images are obtained based on the activated shooting points; Acquire multiple fields of data according to a sensor built into the printer, and determine a printing speed according to the multiple fields of data; A printed model is established according to the actual printing progress, the actual observation image of each shooting point is compared with the theoretical observation image of the corresponding observation point, and the printing speed is adjusted according to the comparison result.

2. The output correction method for multi-field coupling 3D printing according to claim 1, characterized in that: The steps of evenly setting shooting points on the circumference of the printer and setting observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer include: Determine the number of shooting points based on the printer's resources; Get the number of circumferences of the printer, divide the number of shooting points by the number of circumferences and round down to get the number of shooting points on each circumference; For any circumferential surface, a dynamic-size grid is constructed with the endpoints of the circumferential surface as base points, and the number of grid points in the circumferential surface is obtained; the dynamic size is the side length of the grid unit; Keep increasing the dynamic size until the number of grid points is less than the number of shooting points on the surface, and then output the current grid; Read the grid points of the current grid as shooting points; Taking the bottom surface of the model to be printed as the reference, insert the reference planes corresponding to the peripheral surfaces of the printer, and select the observation points corresponding to the shooting points in the reference planes.

3. The output correction method for multi-field coupling 3D printing according to claim 1, characterized in that: The step of obtaining theoretical observation images of each observation point under different printing progresses includes: Add model hiding mask; Get the printing range under different printing progress in the preset printing order; Select an area in the model hidden mask based on the printing range, delete the selected area in the model hidden mask, and obtain the printed model under different printing progress; For any printing progress, an image pointing in the direction of the center of the printed model is obtained at each observation point as a theoretical observation image.

4. The output correction method for multi-field coupling 3D printing according to claim 1, characterized in that: The steps of periodically acquiring the actual printing progress, activating the shooting points, and acquiring the actual observation image based on the activated shooting points during the actual printing process include: During the actual printing process, the actual printing progress is obtained regularly; Randomly select shooting points and activate them; An image pointing to the center of the to-be-printed model is acquired based on the activated shooting point to obtain an actual observation image; Among them, the selection probability of each shooting point is: Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth circumference is selected before the current printing moment; K is the number of circumferences; α is the preset correction coefficient.

5. The output correction method for multi-field coupling 3D printing according to claim 3, characterized in that: The step of establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjusting the printing speed according to the comparison result includes: Read the printed model according to the actual printing progress; Select shooting points in sequence and read the actual observation images at the shooting points; Query the observation point corresponding to the selected shooting point and read the theoretical observation image of the observation point; Perform contour recognition on both the actual observation image and the theoretical observation image to obtain the model contour; A difference contour segment is determined according to the model contour, and a printing speed is adjusted according to the difference contour segment.

6. The output correction method for multi-field coupling 3D printing according to claim 5, characterized in that: The step of determining the difference contour segment according to the model contour and adjusting the printing speed according to the difference contour segment comprises: Get the center of the printed model, and construct a spherical ray group in a preset direction with the center as the starting point; On any ray, query the contour points in the actual observation image and the contour points in the theoretical observation image, and the difference between the two contour points on the ray; Contour points whose statistical difference is greater than a preset threshold are marked as difference contour segments; Count the total length of the difference contour segments in the printed model, and adjust the printing speed according to the total length and actual printing progress; The adjustment range of the printing speed is as follows according to the total length and actual printing progress: Where F is the adjustment range of the printing speed, β is the preset correction coefficient, L is the total length of the difference contour segment, and S is the actual printing progress.

7. An output correction system for multi-field coupling 3D printing, characterized in that: The system comprises: A point position preset module is used to evenly set shooting points on the circumference of the printer, and to set observation points corresponding to the shooting points in the model to be printed according to the positional relationship between the model to be printed and the printer; Theoretical image determination module, used to obtain theoretical observation images of each observation point under different printing progress; An actual image determination module is used to obtain the actual printing progress at regular intervals during the actual printing process, activate the shooting points, and obtain the actual observation image based on the activated shooting points; A multi-field coupling application module, used to obtain multi-field data according to a sensor built into the printer, and determine a printing speed according to the multi-field data; The correction module is used to establish a printed model according to the actual printing progress, compare the actual observation image of each shooting point with the theoretical observation image of the corresponding observation point, and adjust the printing speed according to the comparison result.

8. The output correction system for multi-field coupling 3D printing according to claim 7, characterized in that: The point preset module includes: A quantity determination unit, used for determining the number of shooting points according to the resource quantity of the printer; The point calculation unit is used to obtain the number of the peripheral surface of the printer, and the number of shooting points is divided by the number of peripheral surfaces and rounded down to obtain the number of shooting points on each peripheral surface; A grid application unit is used to construct a grid of dynamic size for any circumference with the endpoints of the circumference as base points, and obtain the number of grid points in the circumference; the dynamic size is the side length of the grid unit; A grid output unit is used to continuously increase the dynamic size until the number of grid points is less than the number of shooting points on the circumference, and output the current grid; A shooting point output unit is used to read the grid points of the current grid as shooting points; The observation point selection unit is used to insert reference surfaces corresponding to the peripheral surfaces of the printer based on the bottom surface of the model to be printed, and select observation points corresponding to the shooting points in the reference surfaces.

9. The output correction system for multi-field coupling 3D printing according to claim 7, characterized in that: The theoretical image determination module comprises: Mask adding unit, used to add model hidden mask; A range acquisition unit, used to acquire the printing range under different printing progress in a preset printing order; A mask deletion unit is used to select an area in the model hidden mask based on the printing range, delete the selected area in the model hidden mask, and obtain a printed model under different printing progress; The first acquisition unit is used to acquire, for any printing progress, an image pointing in the direction of the center of the printed model at each observation point as a theoretical observation image.

10. The output correction system for multi-field coupling 3D printing according to claim 7, characterized in that: The actual image determination module comprises: A progress acquisition unit, used to regularly acquire the actual printing progress during the actual printing process; A shooting point activation unit, used to randomly select shooting points and activate them; A second acquisition unit is used to acquire an image pointing to the center of the to-be-printed model based on the activated shooting point to obtain an actual observation image; Among them, the selection probability of each shooting point is: Where P(i, j) is the probability of selecting a shooting point with coordinates (i, j) in a certain surface, Δt is the time difference between the current moment and the last time the shooting point with coordinates (i, j) was selected; N k (i, j) is the number of times the shooting point with coordinates (i, j) in the kth surface is selected before the current printing time; K is the number of surfaces.

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