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

Abstract

The application 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, which comprises the following steps: acquiring an actual printing progress at a fixed time, activating a shooting point, and acquiring an actual observation image based on the activated shooting point; acquiring multi-field data based on a sensor built in a printer, and determining a printing speed based on the multi-field data; establishing a printed model according to the actual printing progress, comparing the actual observation image of each shooting point with a theoretical observation image of a corresponding observation point, and adjusting the printing speed according to a comparison result. The application introduces a shooting point into the printer, acquires an actual image from the shooting point, determines a theoretical image at the shooting point according to a to-be-printed model, compares the theoretical image with the actual image, can determine whether the current printing state conforms to a theoretical state, and further adjusts the printing speed, so that the printing accuracy of three-dimensional printing is extracted.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of three-dimensional printing control, and particularly relates to an output correction method and system for multiphysics coupled three-dimensional printing. BACKGROUND

[0002] Three-dimensional printing (3D printing) is a layer-by-layer manufacturing technology, also known as additive manufacturing (AM). It is contrary to traditional subtractive manufacturing, and builds objects by layer-by-layer stacking of materials, rather than forming the final shape by cutting or machining solid materials.

[0003] In the three-dimensional printing process, multiple sensors are built into the printer to construct a multiphysics coupled three-dimensional printing architecture. In the existing multiphysics coupled three-dimensional printing, "multiple fields" refer to the coupling and mutual influence of multiple physical fields, which jointly act on different aspects of the three-dimensional printing process, affecting the printing quality, speed and final performance, including thermal field, mechanical field, fluid field and electromagnetic field, etc. Most of these fields belong to conventional physical fields. In fact, with the advancement of technology, the "fields" of the multiphysics coupled three-dimensional printing technology can be further expanded. Visual monitoring parameters can be introduced as a "visual field" into the existing printing process to optimize the printing process.

[0004] Therefore, how to introduce a visual detection process into the existing technical solution to correct the printing process is a technical problem that the present application technical solution wants to solve. SUMMARY

[0005] The present application aims to provide an output correction method and system for multiphysics coupled three-dimensional printing to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution:

[0007] An output correction method for multiphysics coupled three-dimensional printing, the method comprising:

[0008] Uniformly setting shooting points on the peripheral surface of the printer, and setting observation points corresponding to the shooting points in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer;

[0009] Obtaining theoretical observation images of each observation point at different printing progress;

[0010] In 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] acquiring multi-field data according to a sensor built in the printer, determining the printing speed according to the multi-field data;

[0012] establishing a printed model according to an actual printing progress, comparing an actual observation image of each shooting point with a theoretical observation image of a corresponding observation point, and adjusting the printing speed according to a comparison result.

[0013] As a further scheme of the present application, the step of uniformly arranging the shooting points on the circumferential surface of the printer and arranging the observation points corresponding to the shooting points in the model to be printed according to a positional relationship between the model to be printed and the printer comprises:

[0014] determining the number of shooting points according to a resource amount of the printer;

[0015] acquiring the number of circumferential surfaces of the printer, dividing the number of shooting points by the number of circumferential surfaces and taking an integer less than or equal to the result, and obtaining the number of shooting points on each circumferential surface;

[0016] for any circumferential surface, constructing a grid of a dynamic size with an end point of the circumferential surface as a base point, and acquiring the number of grid points in the circumferential surface; the dynamic size is a side length of a grid unit;

[0017] continuously increasing the dynamic size until the number of grid points is less than the number of shooting points on the circumferential surface, and outputting a current grid;

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

[0019] taking the bottom surface of the model to be printed as a reference, inserting reference surfaces corresponding to the circumferential surfaces of the printer, and selecting the observation points corresponding to the shooting points in the reference surfaces.

[0020] As a further scheme of the present application, the step of acquiring the theoretical observation images of the observation points under different printing progresses comprises:

[0021] adding a model hidden mask;

[0022] acquiring a printing range under different printing progresses in a preset printing order;

[0023] selecting regions in the model hidden mask based on the printing range, deleting the selected regions in the model hidden mask, and obtaining the printed models under different printing progresses;

[0024] for any printing progress, acquiring images directed to a center direction of the printed model at the observation points as the theoretical observation images.

[0025] As a further scheme of the present application, the step of acquiring the actual printing progress in the actual printing process, activating the shooting points, and acquiring the actual observation images based on the activated shooting points comprises:

[0026] In the actual printing process, the actual printing progress is acquired in real time;

[0027] Randomly selecting a shooting point and activating;

[0028] Based on the activated shooting point, an image pointing to the center of the to-be-printed model is acquired, and an actual observation image is obtained;

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

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

[0031] As a further scheme of the present application, the step of adjusting the printing speed according to the comparison result comprises:

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

[0033] Selecting the shooting points in sequence and reading the actual observation images at the shooting points;

[0034] Querying the observation points corresponding to the selected shooting points and reading the theoretical observation images of the observation points;

[0035] Performing contour recognition on the actual observation images and the theoretical observation images to obtain a model contour;

[0036] Determining a difference contour section according to the model contour, and adjusting the printing speed according to the difference contour section.

[0037] As a further scheme of the present application, the step of determining the difference contour section according to the model contour and adjusting the printing speed according to the difference contour section comprises:

[0038] Acquiring the center of the printed model, and constructing a group of spherical rays in a preset direction from the center as a starting point;

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

[0040] Counting the contour points with a difference greater than a preset threshold and marking them as difference contour sections;

[0041] The total length of the difference profile section in the printed model is counted, and the printing speed is adjusted according to the total length and the actual printing progress;

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

[0043] In the formula, F is the adjustment range of the printing speed, β is a preset correction coefficient, L is the total length of the difference profile section, and S is the actual printing progress.

[0044] The technical scheme of the present application also provides an output correction system for multi-field coupling three-dimensional printing, which comprises:

[0045] A point preset module is configured to uniformly set a shooting point on the peripheral surface of the printer and set an observation point corresponding to the shooting point in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer;

[0046] A theoretical image determination module is configured to obtain a theoretical observation image of each observation point at different printing progress;

[0047] An actual image determination module is configured to obtain an actual printing progress at regular time intervals in an actual printing process, activate the shooting point, and obtain an actual observation image based on the activated shooting point;

[0048] A multi-field coupling application module is configured to obtain multi-field data by using a sensor built in the printer and determine a printing speed according to the multi-field data;

[0049] A correction module is configured 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 scheme of the present application, the point preset module comprises:

[0051] A number determination unit is configured to determine the number of shooting points according to the resource amount of the printer;

[0052] A point number calculation unit is configured to obtain the number of peripheral surfaces of the printer, divide the number of shooting points by the number of peripheral surfaces and take the integer part, and obtain the number of shooting points on each peripheral surface;

[0053] A grid application unit is configured to construct a grid with a dynamic size taking the end point of the peripheral surface as a base point for any peripheral surface, and obtain the number of grid points in the peripheral surface; the dynamic size is the side length of the grid unit;

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

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

[0056] An observation point selection unit is configured to insert reference surfaces corresponding to the circumferential 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 scheme of the present application, the theoretical image determination module comprises:

[0058] A mask addition unit is configured to add a model hidden mask.

[0059] A range acquisition unit is configured to acquire the printing range under different printing progress under a preset printing order.

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

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

[0062] As a further scheme of the present application, the actual image determination module comprises:

[0063] A progress acquisition unit is configured to acquire the actual printing progress at regular time intervals during the actual printing process.

[0064] A shooting point activation unit is configured to randomly select and activate a shooting point.

[0065] A second acquisition unit is configured to acquire an image pointing to the center of the model to be printed based on the activated shooting point, and obtain an actual observation image.

[0066] The selection probability of each shooting point is:

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

[0068] Compared with the prior art, the present application has the following advantages: the present application introduces a shooting point into the printer, acquires an actual image from the shooting point, and determines a theoretical image at the shooting point based on 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 the printing speed is adjusted, thereby improving the printing accuracy of three-dimensional printing. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention.

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

[0071] Figure 2 This is the first sub-flowchart of the output correction method for multi-field coupled 3D printing.

[0072] Figure 3 This is the second sub-flowchart of the output correction method for multi-field coupled 3D printing.

[0073] Figure 4 This is the third sub-flowchart of the output correction method for multi-field coupled 3D printing.

[0074] Figure 5 This is the fourth sub-flowchart of the output correction method for multi-field coupled 3D printing.

[0075] Figure 6 This is a block diagram of the output correction system used for multi-field coupled 3D printing. Detailed Implementation

[0076] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0077] Figure 1 This is a flowchart of an output correction method for multi-field coupled 3D printing. In this embodiment of the invention, an output correction method for multi-field coupled 3D printing includes:

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

[0079] A 3D printer typically has six surfaces: two bottom surfaces (top and bottom) and four sides (left, right, front, and back). Shooting points are evenly distributed across these six surfaces, and image acquisition devices are installed at these shooting points. The image acquisition devices generally operate in a flashing manner, that is, they take pictures when a shooting command is received or at preset frequencies.

[0080] After the shooting point is determined, mark the point corresponding to the shooting point in the model to be printed, called the observation point. This process is not complex. Align the center of the bottom surface of the model to be printed with the center of the lower bottom surface of the three-dimensional printer to determine the corresponding relationship, obtain the orientation and distance of the shooting point relative to the center of the lower bottom surface of the printer, and then obtain the point at the same orientation and distance based on the center of the bottom surface of the model to be printed, that is, the observation point.

[0081] In simple terms, the generation process of the observation point is to add a point corresponding to the actual shooting point in the model to be printed.

[0082] Step S200: Obtain the theoretical observation image of each observation point at different printing progress;

[0083] Before the three-dimensional printer performs a printing task, the model to be printed will be analyzed to generate a task table. These task tables are segmented, that is, how much content is printed at a time. Each segment is called a printing progress. The printing progress is expressed in percentage. 0% indicates the beginning of printing, 50% indicates that half of the printing is completed, and 100% indicates that the printing is completed. The printing progress is a fixed parameter of the three-dimensional printer and is considered known data in the technical solution of the present application.

[0084] It should be noted that the printing progress is discrete and generally jumps by 1%. If higher precision is desired, the unit can be set to 0.1% or 0.01%.

[0085] Obtain the theoretical observation image at each observation point at different printing progress. This process occurs in the model and is very simple. Connect the observation point and the center to obtain a straight line, obtain a plane perpendicular to the straight line, and then view the plane and adjust the scaling ratio. The model observed at this printing progress is the theoretical observation image.

[0086] Step S300: In the actual printing process, obtain the actual printing progress at regular intervals, activate the shooting point, and obtain the actual observation image based on the activated shooting point;

[0087] In the actual printing process, the three-dimensional printer will display the printing progress in real time, called the actual printing progress. The actual printing progress is activated once for each jump, and the actual observation image is obtained from the activated shooting point.

[0088] In step S200, the theoretical observation image at each printing progress has been obtained. By comparing the actual observation image with the theoretical observation image, it can be determined whether the printing process is normal under the visual angle.

[0089] Step S400: Obtain multiple field data from the sensor built into the printer, and determine the printing speed based on the multiple field data;

[0090] The three-dimensional printer is internally provided with various sensors, such as temperature sensors and humidity sensors, for acquiring the temperature and humidity inside the printer, and each kind of data is represented by a separate matrix, referred to as field data, such as temperature field data and humidity field data, and according to these data, the printing speed can be determined in real time.

[0091] It should be noted that step S400 is actually the prior art, and the existing three-dimensional printer is equipped with sensors and application algorithms of sensing data, and 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] The printed model is a part of the complete to-be-printed model, and the establishment process is not difficult; its role is to count the shooting and analysis results of all shooting points; since the number of shooting points is not unique, setting up a separate analysis process for each shooting point will be very cumbersome, and converting it to a unified model (printed model) can greatly simplify the data analysis difficulty, without considering the situation of each shooting point.

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

[0095] The correction process refers to adjusting the printing speed.

[0096] Figure 2 The first sub-flow block diagram of the output correction method for multi-field coupling three-dimensional printing, the step of uniformly arranging the shooting points on the circumferential surface of the printer and arranging the observation points corresponding to the shooting points in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer comprises:

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

[0098] Step S102: obtaining the number of circumferential surfaces of the printer, dividing the number of shooting points by the number of circumferential surfaces and taking the integer part to obtain the number of shooting points on each circumferential surface;

[0099] Step S103: for any circumferential surface, a grid of dynamic size is constructed with the circumferential surface endpoint as the base point, 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 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;

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

[0102] Step S106: take the bottom surface of the model to be printed as the reference, insert the reference surface corresponding to each circumference of the printer, and select the observation points corresponding to the shooting points in the reference surface.

[0103] The above describes the setting process of the shooting points and the observation points, which is explained as follows:

[0104] Shooting points: the number of shooting points is determined according to the resource amount of the printer, and the more the number of shooting points, the more the resource amount required; the shooting points need to be evenly distributed on each circumference of the printer, and the number of shooting points on each circumference can be obtained by dividing the number of shooting points by the number of circumferences (generally six) and then rounding down.

[0105] In each circumference, a grid is set, and the unit of the grid is continuously enlarged; as the magnification increases, the number of grid nodes in the circumference decreases, until it is less than the number of shooting points on the circumference; when the number of grid nodes is less than the number of shooting points on the circumference, 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, the bottom surface of the model to be printed is taken as the reference, and the reference surface corresponding to each circumference of the printer is inserted, generally six; according to the orientation and distance, the observation points corresponding to the shooting points can be selected in the reference surface.

[0107] Figure 3 The second sub-flow chart for the output correction method for multi-field coupling three-dimensional printing, the step of obtaining the theoretical observation image of each observation point at different printing progress includes:

[0108] Step S201: add a model hidden mask;

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

[0110] Step S203: select regions in the model hidden mask based on the printing range, delete the selected regions in the model hidden mask, and obtain the printed model at different printing progress;

[0111] Step S204: for any printing progress, obtain the image at each observation point pointing to the center direction of the printed model as the theoretical observation image.

[0112] The above provides a specific theoretical observation image generation process, first, a model hidden mask is generated for hiding the entire model to be printed, then, the range printed at different printing progress is obtained, the mask in the range is deleted (at this time, the hidden range is no longer hidden, and the effect is displayed), that is, the printing range is displayed in the model to be printed. This process is essentially a display processing process, which is often used in the field of image processing and belongs to the migration application of image processing technology.

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

[0114] Figure 4 For the third sub-flow chart of the output correction method for multi-field coupling three-dimensional printing, the step of obtaining the actual observation image based on the activated shooting point in the actual printing process includes:

[0115] Step S301: In the actual printing process, the actual printing progress is obtained at a certain time;

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

[0117] Step S303: Based on the activated shooting point, an image pointing to the center of the model to be printed is obtained, and an actual observation image is obtained.

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

[0119] The focus of the above is the selection process of the shooting point, wherein the selection probability of each shooting point is:

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

[0121] The determination logic of the selection probability is: if a shooting point is not selected for a long time, the probability of being selected is larger, and the longer the time is, the larger the probability of being selected is; further, considering the diversity of shooting, the more the angles of shooting are, the better the shooting is, therefore, for each shooting point, the selection times of the shooting points with the same coordinates in all the circumferences are obtained, the larger the selection times are, the smaller the selection probability of the shooting point is; finally, the result is corrected by a pre-set coefficient.

[0122] Figure 5 For the fourth sub-flow block diagram of the output correction method for multi-field coupling three-dimensional printing, the step of adjusting the printing speed according to the comparison result includes:

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

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

[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 the actual observation image and the theoretical observation image to obtain the model contour;

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

[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 sequence, the actual observation image at the shooting point is read, the theoretical observation image at the corresponding observation point is queried synchronously, the 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 section. The difference contour section is the position that does not conform to the theoretical condition in the printing process. The printing speed is adjusted based on the difference contour section. On the basis of the original multi-field coupling, the visual-based adjustment process is introduced.

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

[0130] Obtaining the center of the printed model, and constructing a group of spherical rays in a preset direction from the center as a starting point;

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

[0132] Counting the profile points with a difference greater than a preset threshold, and marking the profile points as a difference profile segment;

[0133] Counting the total length of the difference profile segment in the printed model, and adjusting the printing speed according to the total length and the actual printing progress;

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

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

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

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

[0138] It should be noted that the printing speed adjusted in the present application is reduced, and the smaller the printing speed, the smaller the risk probability, and the better the printing effect. The adjustment range of the reduced printing speed is the above-mentioned adjustment range, which is directly proportional to the ratio of the total length and the actual printing progress, and the adjustment range is adjusted to a preset range by combining the preset correction coefficient.

[0139] Figure 6 The present application is a component structure block diagram of an output correction system for multi-field coupling three-dimensional printing. In the embodiment of the present application, an output correction system for multi-field coupling three-dimensional printing, the system 10 comprises:

[0140] A point preset module 11 is configured to uniformly set a shooting point on the peripheral surface of the printer, and set an observation point corresponding to the shooting point in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer;

[0141] A theoretical image determination module 12 is configured to obtain theoretical observation images of the observation points at different printing progress;

[0142] The actual image determining module 13 is configured to acquire actual printing progress in an actual printing process, activate a shooting point, and acquire an actual observation image based on the activated shooting point.

[0143] The multi-field coupling application module 14 is configured to acquire multi-field data based on a sensor built in the printer, and determine a printing speed based on the multi-field data.

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

[0145] Further, the point position presetting module 11 comprises:

[0146] The number determining unit is configured to determine a number of shooting points based on a resource amount of the printer.

[0147] The point number calculating unit is configured to acquire a number of circumferential surfaces of the printer, divide the number of shooting points by the number of circumferential surfaces and take an integer less than or equal to the result, and obtain a number of shooting points on each circumferential surface.

[0148] The grid application unit is configured to, for any circumferential surface, construct a grid with a dynamic size based on an end point of the circumferential surface, and acquire a number of grid points in the circumferential surface; the dynamic size is a side length of a grid unit.

[0149] The grid output unit is configured to continuously increase the dynamic size until the number of grid points is less than the number of shooting points on the circumferential surface, and output a current grid.

[0150] The shooting point output unit is configured to read the grid points of the current grid as shooting points.

[0151] The observation point selecting unit is configured to take a bottom surface of the model to be printed as a reference, insert reference surfaces corresponding to circumferential surfaces of the printer, and select observation points corresponding to the shooting points in the reference surfaces.

[0152] Specifically, the theoretical image determining module 12 comprises:

[0153] The mask adding unit is configured to add a model hidden mask.

[0154] The range acquiring unit is configured to acquire a printing range under different printing progress in a preset printing order.

[0155] The mask deleting unit is configured to select a region in the model hidden mask based on the printing range, delete the selected region in the model hidden mask, and obtain a printed model under different printing progress.

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

[0157] In addition, the actual image determining module 13 comprises:

[0158] a progress obtaining unit, configured to obtain an actual printing progress at a timing during an actual printing process;

[0159] a shooting point activating unit, configured to randomly select and activate a shooting point;

[0160] a second obtaining unit, configured to obtain an image pointing to a center of the model to be printed based on the activated shooting point, to obtain an actual observation image;

[0161] wherein, a selection probability of each shooting point is:

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

[0163] The preferred embodiments of the present application have been described above with reference to the drawings, but the present application is not limited to the above examples, and any modification, equivalent replacement, and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An output rectification method for multi-field coupled three-dimensional printing, characterized by, The method comprises: Uniformly arranging shooting points on the circumferential surface of the printer, and arranging observation points corresponding to the shooting points in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer; Obtaining theoretical observation images of each observation point under different printing progress; In the actual printing process, the actual printing progress is obtained at regular time intervals, the shooting points are activated, and the actual observation images are obtained based on the activated shooting points; Obtaining multi-field data by a sensor built in the printer, and determining the printing speed according to the multi-field data; According to the actual printing progress, the printed model is established, the actual observation images of each shooting point are compared with the theoretical observation images of the corresponding observation points, and the printing speed is adjusted according to the comparison result; The step of uniformly arranging shooting points on the circumferential surface of the printer, and arranging observation points corresponding to the shooting points in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer comprises: Determining the number of shooting points according to the resource amount of the printer; Obtaining the number of circumferential surfaces of the printer, dividing the number of shooting points by the number of circumferential surfaces and taking the integer part to obtain the number of shooting points on each circumferential surface; For any circumferential surface, a grid of dynamic size is constructed with the end point of the circumferential surface as the base point, and the number of grid points in the circumferential surface is obtained; the dynamic size is the side length of the grid unit; The dynamic size is continuously increased until the number of grid points is less than the number of shooting points on the circumferential surface, and the current grid is output; Reading the grid points of the current grid as shooting points; Taking the bottom surface of the to-be-printed model as the reference, inserting reference surfaces corresponding to each circumferential surface of the printer, and selecting observation points corresponding to the shooting points in the reference surfaces.

2. The output rectification method for multi-field coupled three-dimensional printing according to claim 1, characterized in that, The step of obtaining theoretical observation images of each observation point under different printing progress comprises: Adding a model hidden mask; Obtaining the printing range under different printing progress in the preset printing order; Selecting regions in the model hidden mask based on the printing range, deleting the selected regions in the model hidden mask, and obtaining the printed model under different printing progress; For any printing progress, an image pointing to the center direction of the printed model is obtained at each observation point as a theoretical observation image.

3. The output rectification method for multi-field coupled three-dimensional printing of claim 1, wherein, The step of obtaining the actual printing progress at regular time intervals in the actual printing process, activating the shooting points, and obtaining the actual observation images based on the activated shooting points comprises: In the actual printing process, the actual printing progress is obtained at regular time intervals; Randomly selecting and activating the shooting points; Based on the activated shooting points, an image pointing to the center of the to-be-printed model is obtained to obtain the actual observation image; Wherein, the selection probability of each shooting point is: ; wherein, is the selection probability of a shooting point with coordinates in a certain surface, is the time difference between the current time and the time when the shooting point with coordinates was last selected; is the number of times the shooting point with coordinates in the surface was selected before the current printing time; is the number of surfaces; is a preset correction coefficient.

4. The output rectification method for multi-field coupled three-dimensional printing of claim 2, wherein, The step of establishing the printed model according to the actual printing progress, comparing the actual observation images of each shooting point with the theoretical observation images of the corresponding observation points, and adjusting the printing speed according to the comparison result comprises: Reading the printed model according to the actual printing progress; Selecting the shooting points in turn and reading the actual observation images at the shooting points; Querying the observation points corresponding to the selected shooting points and reading the theoretical observation images of the observation points; Performing contour recognition on the actual observation images and the theoretical observation images to obtain the model contour; Determining the difference contour section according to the model contour, and adjusting the printing speed according to the difference contour section.

5. The output rectification method for multi-field coupled three-dimensional printing according to claim 4, characterized in that, The step of determining the difference contour section according to the model contour, and adjusting the printing speed according to the difference contour section comprises: Acquire the center of the printed model, and construct a group of spherical rays in a preset direction from the center as a 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; Statistical difference contour points greater than the preset threshold, marked as difference contour segment; Statistical difference contour segment length in the printed model, and adjust the printing speed according to the total length and the actual printing progress; The adjustment range of the printing speed according to the total length and the actual printing progress is: ; wherein, is the adjustment range of the printing speed, is the preset correction coefficient, is the total length of the difference profile segment, is the actual printing progress.

6. An output correction system for multi-field coupled three-dimensional printing, characterized by, The system comprises: A point preset module, configured to uniformly set shooting points on the circumferential surface of the printer, and set observation points corresponding to the shooting points in the to-be-printed model according to the positional relationship between the to-be-printed model and the printer; A theoretical image determination module, configured to acquire theoretical observation images of the observation points at different printing progresses; An actual image determination module, configured to acquire the actual printing progress in the actual printing process, activate the shooting points, and acquire actual observation images based on the activated shooting points; A multi-field coupling application module, configured to acquire multi-field data based on a sensor built in the printer, and determine the printing speed based on the multi-field data; A correction module, configured to establish a printed model according to the actual printing progress, compare the actual observation images of the shooting points with the theoretical observation images of the observation points, and adjust the printing speed according to the comparison result; The point preset module comprises: A number determination unit, configured to determine the number of shooting points according to the resource amount of the printer; A point number calculation unit, configured to acquire the number of circumferential surfaces of the printer, divide the number of shooting points by the number of circumferential surfaces, and obtain the number of shooting points on each circumferential surface by rounding down; A grid application unit, configured to, for any circumferential surface, construct a grid of a dynamic size with the end points of the circumferential surface as the base points, and acquire the number of grid points in the circumferential surface; the dynamic size is the side length of the grid unit; A grid output unit, configured to continuously increase the dynamic size until the number of grid points is less than the number of shooting points on the circumferential surface, and output the current grid; A shooting point output unit, configured to read the grid points of the current grid as the shooting points; An observation point selection unit, configured to insert reference planes corresponding to the circumferential surfaces of the printer in the bottom surface of the to-be-printed model as the reference, and select observation points corresponding to the shooting points in the reference planes.

7. The output correction system for multi-field coupled three-dimensional printing of claim 6, wherein, The theoretical image determination module comprises: A mask adding unit, configured to add a model hidden mask; A range acquisition unit, configured to acquire the printing range at different printing progresses under a preset printing sequence; A mask deleting unit, configured to select a region in the model hidden mask based on the printing range, delete the selected region in the model hidden mask, and obtain the printed model at different printing progresses; A first acquisition unit, configured to, for any printing progress, acquire images at the observation points and pointing to the center direction of the printed model as the theoretical observation images.

8. The output correction system for multi-field coupled three-dimensional printing of claim 6, wherein, The actual image determination module comprises: A progress acquisition unit, configured to acquire the actual printing progress at a timing in the actual printing process; A shooting point activation unit, configured to randomly select and activate the shooting points; A second acquisition unit, configured to acquire images pointing to the center of the to-be-printed model based on the activated shooting points, and obtain the actual observation images; Wherein, the selection probability of each shooting point is: ; wherein, is the selection probability of a shooting point with coordinates in a certain surface, is the time difference between the current time and the time when the shooting point with coordinates was last selected; is the number of times the shooting point with coordinates in the surface was selected before the current printing time; is the number of surfaces; is a preset correction coefficient.

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